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<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* This file contains functions for managing user access
*
* <b>Public API vs internals</b>
*
* General users probably only care about
*
* Context handling
* - context_course::instance($courseid), context_module::instance($cm->id), context_coursecat::instance($catid)
* - context::instance_by_id($contextid)
* - $context->get_parent_contexts();
* - $context->get_child_contexts();
*
* Whether the user can do something...
* - has_capability()
* - has_any_capability()
* - has_all_capabilities()
* - require_capability()
* - require_login() (from moodlelib)
* - is_enrolled()
* - is_viewing()
* - is_guest()
* - is_siteadmin()
* - isguestuser()
* - isloggedin()
*
* What courses has this user access to?
* - get_enrolled_users()
*
* What users can do X in this context?
* - get_enrolled_users() - at and bellow course context
* - get_users_by_capability() - above course context
*
* Modify roles
* - role_assign()
* - role_unassign()
* - role_unassign_all()
*
* Advanced - for internal use only
* - load_all_capabilities()
* - reload_all_capabilities()
* - has_capability_in_accessdata()
* - get_user_roles_sitewide_accessdata()
* - etc.
*
* <b>Name conventions</b>
*
* "ctx" means context
* "ra" means role assignment
* "rdef" means role definition
*
* <b>accessdata</b>
*
* Access control data is held in the "accessdata" array
* which - for the logged-in user, will be in $USER->access
*
* For other users can be generated and passed around (but may also be cached
* against userid in $ACCESSLIB_PRIVATE->accessdatabyuser).
*
* $accessdata is a multidimensional array, holding
* role assignments (RAs), role switches and initialization time.
*
* Things are keyed on "contextpaths" (the path field of
* the context table) for fast walking up/down the tree.
* <code>
* $accessdata['ra'][$contextpath] = array($roleid=>$roleid)
* [$contextpath] = array($roleid=>$roleid)
* [$contextpath] = array($roleid=>$roleid)
* </code>
*
* <b>Stale accessdata</b>
*
* For the logged-in user, accessdata is long-lived.
*
* On each pageload we load $ACCESSLIB_PRIVATE->dirtycontexts which lists
* context paths affected by changes. Any check at-or-below
* a dirty context will trigger a transparent reload of accessdata.
*
* Changes at the system level will force the reload for everyone.
*
* <b>Default role caps</b>
* The default role assignment is not in the DB, so we
* add it manually to accessdata.
*
* This means that functions that work directly off the
* DB need to ensure that the default role caps
* are dealt with appropriately.
*
* @package core_access
* @copyright 1999 onwards Martin Dougiamas http://dougiamas.com
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
defined('MOODLE_INTERNAL') || die();
/** No capability change */
define('CAP_INHERIT', 0);
/** Allow permission, overrides CAP_PREVENT defined in parent contexts */
define('CAP_ALLOW', 1);
/** Prevent permission, overrides CAP_ALLOW defined in parent contexts */
define('CAP_PREVENT', -1);
/** Prohibit permission, overrides everything in current and child contexts */
define('CAP_PROHIBIT', -1000);
/** System context level - only one instance in every system */
define('CONTEXT_SYSTEM', 10);
/** User context level - one instance for each user describing what others can do to user */
define('CONTEXT_USER', 30);
/** Course category context level - one instance for each category */
define('CONTEXT_COURSECAT', 40);
/** Course context level - one instances for each course */
define('CONTEXT_COURSE', 50);
/** Course module context level - one instance for each course module */
define('CONTEXT_MODULE', 70);
/**
* Block context level - one instance for each block, sticky blocks are tricky
* because ppl think they should be able to override them at lower contexts.
* Any other context level instance can be parent of block context.
*/
define('CONTEXT_BLOCK', 80);
/** Capability allow management of trusts - NOT IMPLEMENTED YET - see {@link http://docs.moodle.org/dev/Hardening_new_Roles_system} */
define('RISK_MANAGETRUST', 0x0001);
/** Capability allows changes in system configuration - see {@link http://docs.moodle.org/dev/Hardening_new_Roles_system} */
define('RISK_CONFIG', 0x0002);
/** Capability allows user to add scripted content - see {@link http://docs.moodle.org/dev/Hardening_new_Roles_system} */
define('RISK_XSS', 0x0004);
/** Capability allows access to personal user information - see {@link http://docs.moodle.org/dev/Hardening_new_Roles_system} */
define('RISK_PERSONAL', 0x0008);
/** Capability allows users to add content others may see - see {@link http://docs.moodle.org/dev/Hardening_new_Roles_system} */
define('RISK_SPAM', 0x0010);
/** capability allows mass delete of data belonging to other users - see {@link http://docs.moodle.org/dev/Hardening_new_Roles_system} */
define('RISK_DATALOSS', 0x0020);
/** rolename displays - the name as defined in the role definition, localised if name empty */
define('ROLENAME_ORIGINAL', 0);
/** rolename displays - the name as defined by a role alias at the course level, falls back to ROLENAME_ORIGINAL if alias not present */
define('ROLENAME_ALIAS', 1);
/** rolename displays - Both, like this: Role alias (Original) */
define('ROLENAME_BOTH', 2);
/** rolename displays - the name as defined in the role definition and the shortname in brackets */
define('ROLENAME_ORIGINALANDSHORT', 3);
/** rolename displays - the name as defined by a role alias, in raw form suitable for editing */
define('ROLENAME_ALIAS_RAW', 4);
/** rolename displays - the name is simply short role name */
define('ROLENAME_SHORT', 5);
if (!defined('CONTEXT_CACHE_MAX_SIZE')) {
/** maximum size of context cache - it is possible to tweak this config.php or in any script before inclusion of context.php */
define('CONTEXT_CACHE_MAX_SIZE', 2500);
}
/**
* Although this looks like a global variable, it isn't really.
*
* It is just a private implementation detail to accesslib that MUST NOT be used elsewhere.
* It is used to cache various bits of data between function calls for performance reasons.
* Sadly, a PHP global variable is the only way to implement this, without rewriting everything
* as methods of a class, instead of functions.
*
* @access private
* @global stdClass $ACCESSLIB_PRIVATE
* @name $ACCESSLIB_PRIVATE
*/
global $ACCESSLIB_PRIVATE;
$ACCESSLIB_PRIVATE = new stdClass();
$ACCESSLIB_PRIVATE->cacheroledefs = array(); // Holds site-wide role definitions.
$ACCESSLIB_PRIVATE->dirtycontexts = null; // Dirty contexts cache, loaded from DB once per page
$ACCESSLIB_PRIVATE->dirtyusers = null; // Dirty users cache, loaded from DB once per $USER->id
$ACCESSLIB_PRIVATE->accessdatabyuser = array(); // Holds the cache of $accessdata structure for users (including $USER)
/**
* Clears accesslib's private caches. ONLY BE USED BY UNIT TESTS
*
* This method should ONLY BE USED BY UNIT TESTS. It clears all of
* accesslib's private caches. You need to do this before setting up test data,
* and also at the end of the tests.
*
* @access private
* @return void
*/
function accesslib_clear_all_caches_for_unit_testing() {
global $USER;
if (!PHPUNIT_TEST) {
throw new coding_exception('You must not call clear_all_caches outside of unit tests.');
}
accesslib_clear_all_caches(true);
accesslib_reset_role_cache();
unset($USER->access);
}
/**
* Clears accesslib's private caches. ONLY BE USED FROM THIS LIBRARY FILE!
*
* This reset does not touch global $USER.
*
* @access private
* @param bool $resetcontexts
* @return void
*/
function accesslib_clear_all_caches($resetcontexts) {
global $ACCESSLIB_PRIVATE;
$ACCESSLIB_PRIVATE->dirtycontexts = null;
$ACCESSLIB_PRIVATE->dirtyusers = null;
$ACCESSLIB_PRIVATE->accessdatabyuser = array();
if ($resetcontexts) {
context_helper::reset_caches();
}
}
/**
* Full reset of accesslib's private role cache. ONLY TO BE USED FROM THIS LIBRARY FILE!
*
* This reset does not touch global $USER.
*
* Note: Only use this when the roles that need a refresh are unknown.
*
* @see accesslib_clear_role_cache()
*
* @access private
* @return void
*/
function accesslib_reset_role_cache() {
global $ACCESSLIB_PRIVATE;
$ACCESSLIB_PRIVATE->cacheroledefs = array();
$cache = cache::make('core', 'roledefs');
$cache->purge();
}
/**
* Clears accesslib's private cache of a specific role or roles. ONLY BE USED FROM THIS LIBRARY FILE!
*
* This reset does not touch global $USER.
*
* @access private
* @param int|array $roles
* @return void
*/
function accesslib_clear_role_cache($roles) {
global $ACCESSLIB_PRIVATE;
if (!is_array($roles)) {
$roles = [$roles];
}
foreach ($roles as $role) {
if (isset($ACCESSLIB_PRIVATE->cacheroledefs[$role])) {
unset($ACCESSLIB_PRIVATE->cacheroledefs[$role]);
}
}
$cache = cache::make('core', 'roledefs');
$cache->delete_many($roles);
}
/**
* Role is assigned at system context.
*
* @access private
* @param int $roleid
* @return array
*/
function get_role_access($roleid) {
$accessdata = get_empty_accessdata();
$accessdata['ra']['/'.SYSCONTEXTID] = array((int)$roleid => (int)$roleid);
return $accessdata;
}
/**
* Fetch raw "site wide" role definitions.
* Even MUC static acceleration cache appears a bit slow for this.
* Important as can be hit hundreds of times per page.
*
* @param array $roleids List of role ids to fetch definitions for.
* @return array Complete definition for each requested role.
*/
function get_role_definitions(array $roleids) {
global $ACCESSLIB_PRIVATE;
if (empty($roleids)) {
return array();
}
// Grab all keys we have not yet got in our static cache.
if ($uncached = array_diff($roleids, array_keys($ACCESSLIB_PRIVATE->cacheroledefs))) {
$cache = cache::make('core', 'roledefs');
foreach ($cache->get_many($uncached) as $roleid => $cachedroledef) {
if (is_array($cachedroledef)) {
$ACCESSLIB_PRIVATE->cacheroledefs[$roleid] = $cachedroledef;
}
}
// Check we have the remaining keys from the MUC.
if ($uncached = array_diff($roleids, array_keys($ACCESSLIB_PRIVATE->cacheroledefs))) {
$uncached = get_role_definitions_uncached($uncached);
$ACCESSLIB_PRIVATE->cacheroledefs += $uncached;
$cache->set_many($uncached);
}
}
// Return just the roles we need.
return array_intersect_key($ACCESSLIB_PRIVATE->cacheroledefs, array_flip($roleids));
}
/**
* Query raw "site wide" role definitions.
*
* @param array $roleids List of role ids to fetch definitions for.
* @return array Complete definition for each requested role.
*/
function get_role_definitions_uncached(array $roleids) {
global $DB;
if (empty($roleids)) {
return array();
}
// Create a blank results array: even if a role has no capabilities,
// we need to ensure it is included in the results to show we have
// loaded all the capabilities that there are.
$rdefs = array();
foreach ($roleids as $roleid) {
$rdefs[$roleid] = array();
}
// Load all the capabilities for these roles in all contexts.
list($sql, $params) = $DB->get_in_or_equal($roleids);
$sql = "SELECT ctx.path, rc.roleid, rc.capability, rc.permission
FROM {role_capabilities} rc
JOIN {context} ctx ON rc.contextid = ctx.id
JOIN {capabilities} cap ON rc.capability = cap.name
WHERE rc.roleid $sql";
$rs = $DB->get_recordset_sql($sql, $params);
// Store the capabilities into the expected data structure.
foreach ($rs as $rd) {
if (!isset($rdefs[$rd->roleid][$rd->path])) {
$rdefs[$rd->roleid][$rd->path] = array();
}
$rdefs[$rd->roleid][$rd->path][$rd->capability] = (int) $rd->permission;
}
$rs->close();
// Sometimes (e.g. get_user_capability_course_helper::get_capability_info_at_each_context)
// we process role definitinons in a way that requires we see parent contexts
// before child contexts. This sort ensures that works (and is faster than
// sorting in the SQL query).
foreach ($rdefs as $roleid => $rdef) {
ksort($rdefs[$roleid]);
}
return $rdefs;
}
/**
* Get the default guest role, this is used for guest account,
* search engine spiders, etc.
*
* @return stdClass role record
*/
function get_guest_role() {
global $CFG, $DB;
if (empty($CFG->guestroleid)) {
if ($roles = $DB->get_records('role', array('archetype'=>'guest'))) {
$guestrole = array_shift($roles); // Pick the first one
set_config('guestroleid', $guestrole->id);
return $guestrole;
} else {
debugging('Can not find any guest role!');
return false;
}
} else {
if ($guestrole = $DB->get_record('role', array('id'=>$CFG->guestroleid))) {
return $guestrole;
} else {
// somebody is messing with guest roles, remove incorrect setting and try to find a new one
set_config('guestroleid', '');
return get_guest_role();
}
}
}
/**
* Check whether a user has a particular capability in a given context.
*
* For example:
* $context = context_module::instance($cm->id);
* has_capability('mod/forum:replypost', $context)
*
* By default checks the capabilities of the current user, but you can pass a
* different userid. By default will return true for admin users, but you can override that with the fourth argument.
*
* Guest and not-logged-in users can never get any dangerous capability - that is any write capability
* or capabilities with XSS, config or data loss risks.
*
* @category access
*
* @param string $capability the name of the capability to check. For example mod/forum:view
* @param context $context the context to check the capability in. You normally get this with instance method of a context class.
* @param integer|stdClass $user A user id or object. By default (null) checks the permissions of the current user.
* @param boolean $doanything If false, ignores effect of admin role assignment
* @return boolean true if the user has this capability. Otherwise false.
*/
function has_capability($capability, context $context, $user = null, $doanything = true) {
global $USER, $CFG, $SCRIPT, $ACCESSLIB_PRIVATE;
if (during_initial_install()) {
if ($SCRIPT === "/$CFG->admin/index.php"
or $SCRIPT === "/$CFG->admin/cli/install.php"
or $SCRIPT === "/$CFG->admin/cli/install_database.php"
or (defined('BEHAT_UTIL') and BEHAT_UTIL)
or (defined('PHPUNIT_UTIL') and PHPUNIT_UTIL)) {
// we are in an installer - roles can not work yet
return true;
} else {
return false;
}
}
if (strpos($capability, 'moodle/legacy:') === 0) {
throw new coding_exception('Legacy capabilities can not be used any more!');
}
if (!is_bool($doanything)) {
throw new coding_exception('Capability parameter "doanything" is wierd, only true or false is allowed. This has to be fixed in code.');
}
// capability must exist
if (!$capinfo = get_capability_info($capability)) {
debugging('Capability "'.$capability.'" was not found! This has to be fixed in code.');
return false;
}
if (!isset($USER->id)) {
// should never happen
$USER->id = 0;
debugging('Capability check being performed on a user with no ID.', DEBUG_DEVELOPER);
}
// make sure there is a real user specified
if ($user === null) {
$userid = $USER->id;
} else {
$userid = is_object($user) ? $user->id : $user;
}
// make sure forcelogin cuts off not-logged-in users if enabled
if (!empty($CFG->forcelogin) and $userid == 0) {
return false;
}
// make sure the guest account and not-logged-in users never get any risky caps no matter what the actual settings are.
if (($capinfo->captype === 'write') or ($capinfo->riskbitmask & (RISK_XSS | RISK_CONFIG | RISK_DATALOSS))) {
if (isguestuser($userid) or $userid == 0) {
return false;
}
}
// Check whether context locking is enabled.
if (!empty($CFG->contextlocking)) {
if ($capinfo->captype === 'write' && $context->locked) {
// Context locking applies to any write capability in a locked context.
// It does not apply to moodle/site:managecontextlocks - this is to allow context locking to be unlocked.
if ($capinfo->name !== 'moodle/site:managecontextlocks') {
// It applies to all users who are not site admins.
// It also applies to site admins when contextlockappliestoadmin is set.
if (!is_siteadmin($userid) || !empty($CFG->contextlockappliestoadmin)) {
return false;
}
}
}
}
// somehow make sure the user is not deleted and actually exists
if ($userid != 0) {
if ($userid == $USER->id and isset($USER->deleted)) {
// this prevents one query per page, it is a bit of cheating,
// but hopefully session is terminated properly once user is deleted
if ($USER->deleted) {
return false;
}
} else {
if (!context_user::instance($userid, IGNORE_MISSING)) {
// no user context == invalid userid
return false;
}
}
}
// context path/depth must be valid
if (empty($context->path) or $context->depth == 0) {
// this should not happen often, each upgrade tries to rebuild the context paths
debugging('Context id '.$context->id.' does not have valid path, please use context_helper::build_all_paths()');
if (is_siteadmin($userid)) {
return true;
} else {
return false;
}
}
// Find out if user is admin - it is not possible to override the doanything in any way
// and it is not possible to switch to admin role either.
if ($doanything) {
if (is_siteadmin($userid)) {
if ($userid != $USER->id) {
return true;
}
// make sure switchrole is not used in this context
if (empty($USER->access['rsw'])) {
return true;
}
$parts = explode('/', trim($context->path, '/'));
$path = '';
$switched = false;
foreach ($parts as $part) {
$path .= '/' . $part;
if (!empty($USER->access['rsw'][$path])) {
$switched = true;
break;
}
}
if (!$switched) {
return true;
}
//ok, admin switched role in this context, let's use normal access control rules
}
}
// Careful check for staleness...
$context->reload_if_dirty();
if ($USER->id == $userid) {
if (!isset($USER->access)) {
load_all_capabilities();
}
$access =& $USER->access;
} else {
// make sure user accessdata is really loaded
get_user_accessdata($userid, true);
$access =& $ACCESSLIB_PRIVATE->accessdatabyuser[$userid];
}
return has_capability_in_accessdata($capability, $context, $access);
}
/**
* Check if the user has any one of several capabilities from a list.
*
* This is just a utility method that calls has_capability in a loop. Try to put
* the capabilities that most users are likely to have first in the list for best
* performance.
*
* @category access
* @see has_capability()
*
* @param array $capabilities an array of capability names.
* @param context $context the context to check the capability in. You normally get this with instance method of a context class.
* @param integer|stdClass $user A user id or object. By default (null) checks the permissions of the current user.
* @param boolean $doanything If false, ignore effect of admin role assignment
* @return boolean true if the user has any of these capabilities. Otherwise false.
*/
function has_any_capability(array $capabilities, context $context, $user = null, $doanything = true) {
foreach ($capabilities as $capability) {
if (has_capability($capability, $context, $user, $doanything)) {
return true;
}
}
return false;
}
/**
* Check if the user has all the capabilities in a list.
*
* This is just a utility method that calls has_capability in a loop. Try to put
* the capabilities that fewest users are likely to have first in the list for best
* performance.
*
* @category access
* @see has_capability()
*
* @param array $capabilities an array of capability names.
* @param context $context the context to check the capability in. You normally get this with instance method of a context class.
* @param integer|stdClass $user A user id or object. By default (null) checks the permissions of the current user.
* @param boolean $doanything If false, ignore effect of admin role assignment
* @return boolean true if the user has all of these capabilities. Otherwise false.
*/
function has_all_capabilities(array $capabilities, context $context, $user = null, $doanything = true) {
foreach ($capabilities as $capability) {
if (!has_capability($capability, $context, $user, $doanything)) {
return false;
}
}
return true;
}
/**
* Is course creator going to have capability in a new course?
*
* This is intended to be used in enrolment plugins before or during course creation,
* do not use after the course is fully created.
*
* @category access
*
* @param string $capability the name of the capability to check.
* @param context $context course or category context where is course going to be created
* @param integer|stdClass $user A user id or object. By default (null) checks the permissions of the current user.
* @return boolean true if the user will have this capability.
*
* @throws coding_exception if different type of context submitted
*/
function guess_if_creator_will_have_course_capability($capability, context $context, $user = null) {
global $CFG;
if ($context->contextlevel != CONTEXT_COURSE and $context->contextlevel != CONTEXT_COURSECAT) {
throw new coding_exception('Only course or course category context expected');
}
if (has_capability($capability, $context, $user)) {
// User already has the capability, it could be only removed if CAP_PROHIBIT
// was involved here, but we ignore that.
return true;
}
if (!has_capability('moodle/course:create', $context, $user)) {
return false;
}
if (!enrol_is_enabled('manual')) {
return false;
}
if (empty($CFG->creatornewroleid)) {
return false;
}
if ($context->contextlevel == CONTEXT_COURSE) {
if (is_viewing($context, $user, 'moodle/role:assign') or is_enrolled($context, $user, 'moodle/role:assign')) {
return false;
}
} else {
if (has_capability('moodle/course:view', $context, $user) and has_capability('moodle/role:assign', $context, $user)) {
return false;
}
}
// Most likely they will be enrolled after the course creation is finished,
// does the new role have the required capability?
list($neededroles, $forbiddenroles) = get_roles_with_cap_in_context($context, $capability);
return isset($neededroles[$CFG->creatornewroleid]);
}
/**
* Check if the user is an admin at the site level.
*
* Please note that use of proper capabilities is always encouraged,
* this function is supposed to be used from core or for temporary hacks.
*
* @category access
*
* @param int|stdClass $user_or_id user id or user object
* @return bool true if user is one of the administrators, false otherwise
*/
function is_siteadmin($user_or_id = null) {
global $CFG, $USER;
if ($user_or_id === null) {
$user_or_id = $USER;
}
if (empty($user_or_id)) {
return false;
}
if (!empty($user_or_id->id)) {
$userid = $user_or_id->id;
} else {
$userid = $user_or_id;
}
// Because this script is called many times (150+ for course page) with
// the same parameters, it is worth doing minor optimisations. This static
// cache stores the value for a single userid, saving about 2ms from course
// page load time without using significant memory. As the static cache
// also includes the value it depends on, this cannot break unit tests.
static $knownid, $knownresult, $knownsiteadmins;
if ($knownid === $userid && $knownsiteadmins === $CFG->siteadmins) {
return $knownresult;
}
$knownid = $userid;
$knownsiteadmins = $CFG->siteadmins;
$siteadmins = explode(',', $CFG->siteadmins);
$knownresult = in_array($userid, $siteadmins);
return $knownresult;
}
/**
* Returns true if user has at least one role assign
* of 'coursecontact' role (is potentially listed in some course descriptions).
*
* @param int $userid
* @return bool
*/
function has_coursecontact_role($userid) {
global $DB, $CFG;
if (empty($CFG->coursecontact)) {
return false;
}
$sql = "SELECT 1
FROM {role_assignments}
WHERE userid = :userid AND roleid IN ($CFG->coursecontact)";
return $DB->record_exists_sql($sql, array('userid'=>$userid));
}
/**
* Does the user have a capability to do something?
*
* Walk the accessdata array and return true/false.
* Deals with prohibits, role switching, aggregating
* capabilities, etc.
*
* The main feature of here is being FAST and with no
* side effects.
*
* Notes:
*
* Switch Role merges with default role
* ------------------------------------
* If you are a teacher in course X, you have at least
* teacher-in-X + defaultloggedinuser-sitewide. So in the
* course you'll have techer+defaultloggedinuser.
* We try to mimic that in switchrole.
*
* Permission evaluation
* ---------------------
* Originally there was an extremely complicated way
* to determine the user access that dealt with
* "locality" or role assignments and role overrides.
* Now we simply evaluate access for each role separately
* and then verify if user has at least one role with allow
* and at the same time no role with prohibit.
*
* @access private
* @param string $capability
* @param context $context
* @param array $accessdata
* @return bool
*/
function has_capability_in_accessdata($capability, context $context, array &$accessdata) {
global $CFG;
// Build $paths as a list of current + all parent "paths" with order bottom-to-top
$path = $context->path;
$paths = array($path);
while ($path = rtrim($path, '0123456789')) {
$path = rtrim($path, '/');
if ($path === '') {
break;
}
$paths[] = $path;
}
$roles = array();
$switchedrole = false;
// Find out if role switched
if (!empty($accessdata['rsw'])) {
// From the bottom up...
foreach ($paths as $path) {
if (isset($accessdata['rsw'][$path])) {
// Found a switchrole assignment - check for that role _plus_ the default user role
$roles = array($accessdata['rsw'][$path]=>null, $CFG->defaultuserroleid=>null);
$switchedrole = true;
break;
}
}
}
if (!$switchedrole) {
// get all users roles in this context and above
foreach ($paths as $path) {
if (isset($accessdata['ra'][$path])) {
foreach ($accessdata['ra'][$path] as $roleid) {
$roles[$roleid] = null;
}
}
}
}
// Now find out what access is given to each role, going bottom-->up direction
$rdefs = get_role_definitions(array_keys($roles));
$allowed = false;
foreach ($roles as $roleid => $ignored) {
foreach ($paths as $path) {
if (isset($rdefs[$roleid][$path][$capability])) {
$perm = (int)$rdefs[$roleid][$path][$capability];
if ($perm === CAP_PROHIBIT) {
// any CAP_PROHIBIT found means no permission for the user
return false;
}
if (is_null($roles[$roleid])) {
$roles[$roleid] = $perm;
}
}
}
// CAP_ALLOW in any role means the user has a permission, we continue only to detect prohibits
$allowed = ($allowed or $roles[$roleid] === CAP_ALLOW);
}
return $allowed;
}
/**
* A convenience function that tests has_capability, and displays an error if
* the user does not have that capability.
*
* NOTE before Moodle 2.0, this function attempted to make an appropriate
* require_login call before checking the capability. This is no longer the case.
* You must call require_login (or one of its variants) if you want to check the
* user is logged in, before you call this function.
*
* @see has_capability()
*
* @param string $capability the name of the capability to check. For example mod/forum:view
* @param context $context the context to check the capability in. You normally get this with context_xxxx::instance().
* @param int $userid A user id. By default (null) checks the permissions of the current user.
* @param bool $doanything If false, ignore effect of admin role assignment
* @param string $errormessage The error string to to user. Defaults to 'nopermissions'.
* @param string $stringfile The language file to load the error string from. Defaults to 'error'.
* @return void terminates with an error if the user does not have the given capability.
*/
function require_capability($capability, context $context, $userid = null, $doanything = true,
$errormessage = 'nopermissions', $stringfile = '') {
if (!has_capability($capability, $context, $userid, $doanything)) {
throw new required_capability_exception($context, $capability, $errormessage, $stringfile);
}
}
/**
* A convenience function that tests has_capability for a list of capabilities, and displays an error if
* the user does not have that capability.
*
* This is just a utility method that calls has_capability in a loop. Try to put
* the capabilities that fewest users are likely to have first in the list for best
* performance.
*
* @category access
* @see has_capability()
*
* @param array $capabilities an array of capability names.
* @param context $context the context to check the capability in. You normally get this with context_xxxx::instance().
* @param int $userid A user id. By default (null) checks the permissions of the current user.
* @param bool $doanything If false, ignore effect of admin role assignment
* @param string $errormessage The error string to to user. Defaults to 'nopermissions'.
* @param string $stringfile The language file to load the error string from. Defaults to 'error'.
* @return void terminates with an error if the user does not have the given capability.
*/
function require_all_capabilities(array $capabilities, context $context, $userid = null, $doanything = true,
$errormessage = 'nopermissions', $stringfile = ''): void {
foreach ($capabilities as $capability) {
if (!has_capability($capability, $context, $userid, $doanything)) {
throw new required_capability_exception($context, $capability, $errormessage, $stringfile);
}
}
}
/**
* Return a nested array showing all role assignments for the user.
* [ra] => [contextpath][roleid] = roleid
*
* @access private
* @param int $userid - the id of the user
* @return array access info array
*/
function get_user_roles_sitewide_accessdata($userid) {
global $CFG, $DB;
$accessdata = get_empty_accessdata();
// start with the default role
if (!empty($CFG->defaultuserroleid)) {
$syscontext = context_system::instance();
$accessdata['ra'][$syscontext->path][(int)$CFG->defaultuserroleid] = (int)$CFG->defaultuserroleid;
}
// load the "default frontpage role"
if (!empty($CFG->defaultfrontpageroleid)) {
$frontpagecontext = context_course::instance(get_site()->id);
if ($frontpagecontext->path) {
$accessdata['ra'][$frontpagecontext->path][(int)$CFG->defaultfrontpageroleid] = (int)$CFG->defaultfrontpageroleid;
}
}
// Preload every assigned role.
$sql = "SELECT ctx.path, ra.roleid, ra.contextid
FROM {role_assignments} ra
JOIN {context} ctx ON ctx.id = ra.contextid
WHERE ra.userid = :userid";
$rs = $DB->get_recordset_sql($sql, array('userid' => $userid));
foreach ($rs as $ra) {
// RAs leafs are arrays to support multi-role assignments...
$accessdata['ra'][$ra->path][(int)$ra->roleid] = (int)$ra->roleid;
}
$rs->close();
return $accessdata;
}
/**
* Returns empty accessdata structure.
*
* @access private
* @return array empt accessdata
*/
function get_empty_accessdata() {
$accessdata = array(); // named list
$accessdata['ra'] = array();
$accessdata['time'] = time();
$accessdata['rsw'] = array();
return $accessdata;
}
/**
* Get accessdata for a given user.
*
* @access private
* @param int $userid
* @param bool $preloadonly true means do not return access array
* @return array accessdata
*/
function get_user_accessdata($userid, $preloadonly=false) {
global $CFG, $ACCESSLIB_PRIVATE, $USER;
if (isset($USER->access)) {
$ACCESSLIB_PRIVATE->accessdatabyuser[$USER->id] = $USER->access;
}
if (!isset($ACCESSLIB_PRIVATE->accessdatabyuser[$userid])) {
if (empty($userid)) {
if (!empty($CFG->notloggedinroleid)) {
$accessdata = get_role_access($CFG->notloggedinroleid);
} else {
// weird
return get_empty_accessdata();
}
} else if (isguestuser($userid)) {
if ($guestrole = get_guest_role()) {
$accessdata = get_role_access($guestrole->id);
} else {
//weird
return get_empty_accessdata();
}
} else {
// Includes default role and frontpage role.
$accessdata = get_user_roles_sitewide_accessdata($userid);
}
$ACCESSLIB_PRIVATE->accessdatabyuser[$userid] = $accessdata;
}
if ($preloadonly) {
return;
} else {
return $ACCESSLIB_PRIVATE->accessdatabyuser[$userid];
}
}
/**
* A convenience function to completely load all the capabilities
* for the current user. It is called from has_capability() and functions change permissions.
*
* Call it only _after_ you've setup $USER and called check_enrolment_plugins();
* @see check_enrolment_plugins()
*
* @access private
* @return void
*/
function load_all_capabilities() {
global $USER;
// roles not installed yet - we are in the middle of installation
if (during_initial_install()) {
return;
}
if (!isset($USER->id)) {
// this should not happen
$USER->id = 0;
}
unset($USER->access);
$USER->access = get_user_accessdata($USER->id);
// Clear to force a refresh
unset($USER->mycourses);
// init/reset internal enrol caches - active course enrolments and temp access
$USER->enrol = array('enrolled'=>array(), 'tempguest'=>array());
}
/**
* A convenience function to completely reload all the capabilities
* for the current user when roles have been updated in a relevant
* context -- but PRESERVING switchroles and loginas.
* This function resets all accesslib and context caches.
*
* That is - completely transparent to the user.
*
* Note: reloads $USER->access completely.
*
* @access private
* @return void
*/
function reload_all_capabilities() {
global $USER, $DB, $ACCESSLIB_PRIVATE;
// copy switchroles
$sw = array();
if (!empty($USER->access['rsw'])) {
$sw = $USER->access['rsw'];
}
accesslib_clear_all_caches(true);
unset($USER->access);
// Prevent dirty flags refetching on this page.
$ACCESSLIB_PRIVATE->dirtycontexts = array();
$ACCESSLIB_PRIVATE->dirtyusers = array($USER->id => false);
load_all_capabilities();
foreach ($sw as $path => $roleid) {
if ($record = $DB->get_record('context', array('path'=>$path))) {
$context = context::instance_by_id($record->id);
if (has_capability('moodle/role:switchroles', $context)) {
role_switch($roleid, $context);
}
}
}
}
/**
* Adds a temp role to current USER->access array.
*
* Useful for the "temporary guest" access we grant to logged-in users.
* This is useful for enrol plugins only.
*
* @since Moodle 2.2
* @param context_course $coursecontext
* @param int $roleid
* @return void
*/
function load_temp_course_role(context_course $coursecontext, $roleid) {
global $USER, $SITE;
if (empty($roleid)) {
debugging('invalid role specified in load_temp_course_role()');
return;
}
if ($coursecontext->instanceid == $SITE->id) {
debugging('Can not use temp roles on the frontpage');
return;
}
if (!isset($USER->access)) {
load_all_capabilities();
}
$coursecontext->reload_if_dirty();
if (isset($USER->access['ra'][$coursecontext->path][$roleid])) {
return;
}
$USER->access['ra'][$coursecontext->path][(int)$roleid] = (int)$roleid;
}
/**
* Removes any extra guest roles from current USER->access array.
* This is useful for enrol plugins only.
*
* @since Moodle 2.2
* @param context_course $coursecontext
* @return void
*/
function remove_temp_course_roles(context_course $coursecontext) {
global $DB, $USER, $SITE;
if ($coursecontext->instanceid == $SITE->id) {
debugging('Can not use temp roles on the frontpage');
return;
}
if (empty($USER->access['ra'][$coursecontext->path])) {
//no roles here, weird
return;
}
$sql = "SELECT DISTINCT ra.roleid AS id
FROM {role_assignments} ra
WHERE ra.contextid = :contextid AND ra.userid = :userid";
$ras = $DB->get_records_sql($sql, array('contextid'=>$coursecontext->id, 'userid'=>$USER->id));
$USER->access['ra'][$coursecontext->path] = array();
foreach ($ras as $r) {
$USER->access['ra'][$coursecontext->path][(int)$r->id] = (int)$r->id;
}
}
/**
* Returns array of all role archetypes.
*
* @return array
*/
function get_role_archetypes() {
return array(
'manager' => 'manager',
'coursecreator' => 'coursecreator',
'editingteacher' => 'editingteacher',
'teacher' => 'teacher',
'student' => 'student',
'guest' => 'guest',
'user' => 'user',
'frontpage' => 'frontpage'
);
}
/**
* Assign the defaults found in this capability definition to roles that have
* the corresponding legacy capabilities assigned to them.
*
* @param string $capability
* @param array $legacyperms an array in the format (example):
* 'guest' => CAP_PREVENT,
* 'student' => CAP_ALLOW,
* 'teacher' => CAP_ALLOW,
* 'editingteacher' => CAP_ALLOW,
* 'coursecreator' => CAP_ALLOW,
* 'manager' => CAP_ALLOW
* @return boolean success or failure.
*/
function assign_legacy_capabilities($capability, $legacyperms) {
$archetypes = get_role_archetypes();
foreach ($legacyperms as $type => $perm) {
$systemcontext = context_system::instance();
if ($type === 'admin') {
debugging('Legacy type admin in access.php was renamed to manager, please update the code.');
$type = 'manager';
}
if (!array_key_exists($type, $archetypes)) {
print_error('invalidlegacy', '', '', $type);
}
if ($roles = get_archetype_roles($type)) {
foreach ($roles as $role) {
// Assign a site level capability.
if (!assign_capability($capability, $perm, $role->id, $systemcontext->id)) {
return false;
}
}
}
}
return true;
}
/**
* Verify capability risks.
*
* @param stdClass $capability a capability - a row from the capabilities table.
* @return boolean whether this capability is safe - that is, whether people with the
* safeoverrides capability should be allowed to change it.
*/
function is_safe_capability($capability) {
return !((RISK_DATALOSS | RISK_MANAGETRUST | RISK_CONFIG | RISK_XSS | RISK_PERSONAL) & $capability->riskbitmask);
}
/**
* Get the local override (if any) for a given capability in a role in a context
*
* @param int $roleid
* @param int $contextid
* @param string $capability
* @return stdClass local capability override
*/
function get_local_override($roleid, $contextid, $capability) {
global $DB;
return $DB->get_record_sql("
SELECT rc.*
FROM {role_capabilities} rc
JOIN {capability} cap ON rc.capability = cap.name
WHERE rc.roleid = :roleid AND rc.capability = :capability AND rc.contextid = :contextid", [
'roleid' => $roleid,
'contextid' => $contextid,
'capability' => $capability,
]);
}
/**
* Returns context instance plus related course and cm instances
*
* @param int $contextid
* @return array of ($context, $course, $cm)
*/
function get_context_info_array($contextid) {
global $DB;
$context = context::instance_by_id($contextid, MUST_EXIST);
$course = null;
$cm = null;
if ($context->contextlevel == CONTEXT_COURSE) {
$course = $DB->get_record('course', array('id'=>$context->instanceid), '*', MUST_EXIST);
} else if ($context->contextlevel == CONTEXT_MODULE) {
$cm = get_coursemodule_from_id('', $context->instanceid, 0, false, MUST_EXIST);
$course = $DB->get_record('course', array('id'=>$cm->course), '*', MUST_EXIST);
} else if ($context->contextlevel == CONTEXT_BLOCK) {
$parent = $context->get_parent_context();
if ($parent->contextlevel == CONTEXT_COURSE) {
$course = $DB->get_record('course', array('id'=>$parent->instanceid), '*', MUST_EXIST);
} else if ($parent->contextlevel == CONTEXT_MODULE) {
$cm = get_coursemodule_from_id('', $parent->instanceid, 0, false, MUST_EXIST);
$course = $DB->get_record('course', array('id'=>$cm->course), '*', MUST_EXIST);
}
}
return array($context, $course, $cm);
}
/**
* Function that creates a role
*
* @param string $name role name
* @param string $shortname role short name
* @param string $description role description
* @param string $archetype
* @return int id or dml_exception
*/
function create_role($name, $shortname, $description, $archetype = '') {
global $DB;
if (strpos($archetype, 'moodle/legacy:') !== false) {
throw new coding_exception('Use new role archetype parameter in create_role() instead of old legacy capabilities.');
}
// verify role archetype actually exists
$archetypes = get_role_archetypes();
if (empty($archetypes[$archetype])) {
$archetype = '';
}
// Insert the role record.
$role = new stdClass();
$role->name = $name;
$role->shortname = $shortname;
$role->description = $description;
$role->archetype = $archetype;
//find free sortorder number
$role->sortorder = $DB->get_field('role', 'MAX(sortorder) + 1', array());
if (empty($role->sortorder)) {
$role->sortorder = 1;
}
$id = $DB->insert_record('role', $role);
return $id;
}
/**
* Function that deletes a role and cleanups up after it
*
* @param int $roleid id of role to delete
* @return bool always true
*/
function delete_role($roleid) {
global $DB;
// first unssign all users
role_unassign_all(array('roleid'=>$roleid));
// cleanup all references to this role, ignore errors
$DB->delete_records('role_capabilities', array('roleid'=>$roleid));
$DB->delete_records('role_allow_assign', array('roleid'=>$roleid));
$DB->delete_records('role_allow_assign', array('allowassign'=>$roleid));
$DB->delete_records('role_allow_override', array('roleid'=>$roleid));
$DB->delete_records('role_allow_override', array('allowoverride'=>$roleid));
$DB->delete_records('role_names', array('roleid'=>$roleid));
$DB->delete_records('role_context_levels', array('roleid'=>$roleid));
// Get role record before it's deleted.
$role = $DB->get_record('role', array('id'=>$roleid));
// Finally delete the role itself.
$DB->delete_records('role', array('id'=>$roleid));
// Trigger event.
$event = \core\event\role_deleted::create(
array(
'context' => context_system::instance(),
'objectid' => $roleid,
'other' =>
array(
'shortname' => $role->shortname,
'description' => $role->description,
'archetype' => $role->archetype
)
)
);
$event->add_record_snapshot('role', $role);
$event->trigger();
// Reset any cache of this role, including MUC.
accesslib_clear_role_cache($roleid);
return true;
}
/**
* Function to write context specific overrides, or default capabilities.
*
* @param string $capability string name
* @param int $permission CAP_ constants
* @param int $roleid role id
* @param int|context $contextid context id
* @param bool $overwrite
* @return bool always true or exception
*/
function assign_capability($capability, $permission, $roleid, $contextid, $overwrite = false) {
global $USER, $DB;
if ($contextid instanceof context) {
$context = $contextid;
} else {
$context = context::instance_by_id($contextid);
}
// Capability must exist.
if (!$capinfo = get_capability_info($capability)) {
throw new coding_exception("Capability '{$capability}' was not found! This has to be fixed in code.");
}
if (empty($permission) || $permission == CAP_INHERIT) { // if permission is not set
unassign_capability($capability, $roleid, $context->id);
return true;
}
$existing = $DB->get_record('role_capabilities', array('contextid'=>$context->id, 'roleid'=>$roleid, 'capability'=>$capability));
if ($existing and !$overwrite) { // We want to keep whatever is there already
return true;
}
$cap = new stdClass();
$cap->contextid = $context->id;
$cap->roleid = $roleid;
$cap->capability = $capability;
$cap->permission = $permission;
$cap->timemodified = time();
$cap->modifierid = empty($USER->id) ? 0 : $USER->id;
if ($existing) {
$cap->id = $existing->id;
$DB->update_record('role_capabilities', $cap);
} else {
if ($DB->record_exists('context', array('id'=>$context->id))) {
$DB->insert_record('role_capabilities', $cap);
}
}
// Trigger capability_assigned event.
\core\event\capability_assigned::create([
'userid' => $cap->modifierid,
'context' => $context,
'objectid' => $roleid,
'other' => [
'capability' => $capability,
'oldpermission' => $existing->permission ?? CAP_INHERIT,
'permission' => $permission
]
])->trigger();
// Reset any cache of this role, including MUC.
accesslib_clear_role_cache($roleid);
return true;
}
/**
* Unassign a capability from a role.
*
* @param string $capability the name of the capability
* @param int $roleid the role id
* @param int|context $contextid null means all contexts
* @return boolean true or exception
*/
function unassign_capability($capability, $roleid, $contextid = null) {
global $DB, $USER;
// Capability must exist.
if (!$capinfo = get_capability_info($capability)) {
throw new coding_exception("Capability '{$capability}' was not found! This has to be fixed in code.");
}
if (!empty($contextid)) {
if ($contextid instanceof context) {
$context = $contextid;
} else {
$context = context::instance_by_id($contextid);
}
// delete from context rel, if this is the last override in this context
$DB->delete_records('role_capabilities', array('capability'=>$capability, 'roleid'=>$roleid, 'contextid'=>$context->id));
} else {
$DB->delete_records('role_capabilities', array('capability'=>$capability, 'roleid'=>$roleid));
}
// Trigger capability_assigned event.
\core\event\capability_unassigned::create([
'userid' => $USER->id,
'context' => $context ?? context_system::instance(),
'objectid' => $roleid,
'other' => [
'capability' => $capability,
]
])->trigger();
// Reset any cache of this role, including MUC.
accesslib_clear_role_cache($roleid);
return true;
}
/**
* Get the roles that have a given capability assigned to it
*
* This function does not resolve the actual permission of the capability.
* It just checks for permissions and overrides.
* Use get_roles_with_cap_in_context() if resolution is required.
*
* @param string $capability capability name (string)
* @param string $permission optional, the permission defined for this capability
* either CAP_ALLOW, CAP_PREVENT or CAP_PROHIBIT. Defaults to null which means any.
* @param stdClass $context null means any
* @return array of role records
*/
function get_roles_with_capability($capability, $permission = null, $context = null) {
global $DB;
if ($context) {
$contexts = $context->get_parent_context_ids(true);
list($insql, $params) = $DB->get_in_or_equal($contexts, SQL_PARAMS_NAMED, 'ctx');
$contextsql = "AND rc.contextid $insql";
} else {
$params = array();
$contextsql = '';
}
if ($permission) {
$permissionsql = " AND rc.permission = :permission";
$params['permission'] = $permission;
} else {
$permissionsql = '';
}
$sql = "SELECT r.*
FROM {role} r
WHERE r.id IN (SELECT rc.roleid
FROM {role_capabilities} rc
JOIN {capabilities} cap ON rc.capability = cap.name
WHERE rc.capability = :capname
$contextsql
$permissionsql)";
$params['capname'] = $capability;
return $DB->get_records_sql($sql, $params);
}
/**
* This function makes a role-assignment (a role for a user in a particular context)
*
* @param int $roleid the role of the id
* @param int $userid userid
* @param int|context $contextid id of the context
* @param string $component example 'enrol_ldap', defaults to '' which means manual assignment,
* @param int $itemid id of enrolment/auth plugin
* @param string $timemodified defaults to current time
* @return int new/existing id of the assignment
*/
function role_assign($roleid, $userid, $contextid, $component = '', $itemid = 0, $timemodified = '') {
global $USER, $DB;
// first of all detect if somebody is using old style parameters
if ($contextid === 0 or is_numeric($component)) {
throw new coding_exception('Invalid call to role_assign(), code needs to be updated to use new order of parameters');
}
// now validate all parameters
if (empty($roleid)) {
throw new coding_exception('Invalid call to role_assign(), roleid can not be empty');
}
if (empty($userid)) {
throw new coding_exception('Invalid call to role_assign(), userid can not be empty');
}
if ($itemid) {
if (strpos($component, '_') === false) {
throw new coding_exception('Invalid call to role_assign(), component must start with plugin type such as"enrol_" when itemid specified', 'component:'.$component);
}
} else {
$itemid = 0;
if ($component !== '' and strpos($component, '_') === false) {
throw new coding_exception('Invalid call to role_assign(), invalid component string', 'component:'.$component);
}
}
if (!$DB->record_exists('user', array('id'=>$userid, 'deleted'=>0))) {
throw new coding_exception('User ID does not exist or is deleted!', 'userid:'.$userid);
}
if ($contextid instanceof context) {
$context = $contextid;
} else {
$context = context::instance_by_id($contextid, MUST_EXIST);
}
if (!$timemodified) {
$timemodified = time();
}
// Check for existing entry
$ras = $DB->get_records('role_assignments', array('roleid'=>$roleid, 'contextid'=>$context->id, 'userid'=>$userid, 'component'=>$component, 'itemid'=>$itemid), 'id');
if ($ras) {
// role already assigned - this should not happen
if (count($ras) > 1) {
// very weird - remove all duplicates!
$ra = array_shift($ras);
foreach ($ras as $r) {
$DB->delete_records('role_assignments', array('id'=>$r->id));
}
} else {
$ra = reset($ras);
}
// actually there is no need to update, reset anything or trigger any event, so just return
return $ra->id;
}
// Create a new entry
$ra = new stdClass();
$ra->roleid = $roleid;
$ra->contextid = $context->id;
$ra->userid = $userid;
$ra->component = $component;
$ra->itemid = $itemid;
$ra->timemodified = $timemodified;
$ra->modifierid = empty($USER->id) ? 0 : $USER->id;
$ra->sortorder = 0;
$ra->id = $DB->insert_record('role_assignments', $ra);
// Role assignments have changed, so mark user as dirty.
mark_user_dirty($userid);
core_course_category::role_assignment_changed($roleid, $context);
$event = \core\event\role_assigned::create(array(
'context' => $context,
'objectid' => $ra->roleid,
'relateduserid' => $ra->userid,
'other' => array(
'id' => $ra->id,
'component' => $ra->component,
'itemid' => $ra->itemid
)
));
$event->add_record_snapshot('role_assignments', $ra);
$event->trigger();
return $ra->id;
}
/**
* Removes one role assignment
*
* @param int $roleid
* @param int $userid
* @param int $contextid
* @param string $component
* @param int $itemid
* @return void
*/
function role_unassign($roleid, $userid, $contextid, $component = '', $itemid = 0) {
// first make sure the params make sense
if ($roleid == 0 or $userid == 0 or $contextid == 0) {
throw new coding_exception('Invalid call to role_unassign(), please use role_unassign_all() when removing multiple role assignments');
}
if ($itemid) {
if (strpos($component, '_') === false) {
throw new coding_exception('Invalid call to role_assign(), component must start with plugin type such as "enrol_" when itemid specified', 'component:'.$component);
}
} else {
$itemid = 0;
if ($component !== '' and strpos($component, '_') === false) {
throw new coding_exception('Invalid call to role_assign(), invalid component string', 'component:'.$component);
}
}
role_unassign_all(array('roleid'=>$roleid, 'userid'=>$userid, 'contextid'=>$contextid, 'component'=>$component, 'itemid'=>$itemid), false, false);
}
/**
* Removes multiple role assignments, parameters may contain:
* 'roleid', 'userid', 'contextid', 'component', 'enrolid'.
*
* @param array $params role assignment parameters
* @param bool $subcontexts unassign in subcontexts too
* @param bool $includemanual include manual role assignments too
* @return void
*/
function role_unassign_all(array $params, $subcontexts = false, $includemanual = false) {
global $USER, $CFG, $DB;
if (!$params) {
throw new coding_exception('Missing parameters in role_unsassign_all() call');
}
$allowed = array('roleid', 'userid', 'contextid', 'component', 'itemid');
foreach ($params as $key=>$value) {
if (!in_array($key, $allowed)) {
throw new coding_exception('Unknown role_unsassign_all() parameter key', 'key:'.$key);
}
}
if (isset($params['component']) and $params['component'] !== '' and strpos($params['component'], '_') === false) {
throw new coding_exception('Invalid component paramter in role_unsassign_all() call', 'component:'.$params['component']);
}
if ($includemanual) {
if (!isset($params['component']) or $params['component'] === '') {
throw new coding_exception('include manual parameter requires component parameter in role_unsassign_all() call');
}
}
if ($subcontexts) {
if (empty($params['contextid'])) {
throw new coding_exception('subcontexts paramtere requires component parameter in role_unsassign_all() call');
}
}
$ras = $DB->get_records('role_assignments', $params);
foreach ($ras as $ra) {
$DB->delete_records('role_assignments', array('id'=>$ra->id));
if ($context = context::instance_by_id($ra->contextid, IGNORE_MISSING)) {
// Role assignments have changed, so mark user as dirty.
mark_user_dirty($ra->userid);
$event = \core\event\role_unassigned::create(array(
'context' => $context,
'objectid' => $ra->roleid,
'relateduserid' => $ra->userid,
'other' => array(
'id' => $ra->id,
'component' => $ra->component,
'itemid' => $ra->itemid
)
));
$event->add_record_snapshot('role_assignments', $ra);
$event->trigger();
core_course_category::role_assignment_changed($ra->roleid, $context);
}
}
unset($ras);
// process subcontexts
if ($subcontexts and $context = context::instance_by_id($params['contextid'], IGNORE_MISSING)) {
if ($params['contextid'] instanceof context) {
$context = $params['contextid'];
} else {
$context = context::instance_by_id($params['contextid'], IGNORE_MISSING);
}
if ($context) {
$contexts = $context->get_child_contexts();
$mparams = $params;
foreach ($contexts as $context) {
$mparams['contextid'] = $context->id;
$ras = $DB->get_records('role_assignments', $mparams);
foreach ($ras as $ra) {
$DB->delete_records('role_assignments', array('id'=>$ra->id));
// Role assignments have changed, so mark user as dirty.
mark_user_dirty($ra->userid);
$event = \core\event\role_unassigned::create(
array('context'=>$context, 'objectid'=>$ra->roleid, 'relateduserid'=>$ra->userid,
'other'=>array('id'=>$ra->id, 'component'=>$ra->component, 'itemid'=>$ra->itemid)));
$event->add_record_snapshot('role_assignments', $ra);
$event->trigger();
core_course_category::role_assignment_changed($ra->roleid, $context);
}
}
}
}
// do this once more for all manual role assignments
if ($includemanual) {
$params['component'] = '';
role_unassign_all($params, $subcontexts, false);
}
}
/**
* Mark a user as dirty (with timestamp) so as to force reloading of the user session.
*
* @param int $userid
* @return void
*/
function mark_user_dirty($userid) {
global $CFG, $ACCESSLIB_PRIVATE;
if (during_initial_install()) {
return;
}
// Throw exception if invalid userid is provided.
if (empty($userid)) {
throw new coding_exception('Invalid user parameter supplied for mark_user_dirty() function!');
}
// Set dirty flag in database, set dirty field locally, and clear local accessdata cache.
set_cache_flag('accesslib/dirtyusers', $userid, 1, time() + $CFG->sessiontimeout);
$ACCESSLIB_PRIVATE->dirtyusers[$userid] = 1;
unset($ACCESSLIB_PRIVATE->accessdatabyuser[$userid]);
}
/**
* Determines if a user is currently logged in
*
* @category access
*
* @return bool
*/
function isloggedin() {
global $USER;
return (!empty($USER->id));
}
/**
* Determines if a user is logged in as real guest user with username 'guest'.
*
* @category access
*
* @param int|object $user mixed user object or id, $USER if not specified
* @return bool true if user is the real guest user, false if not logged in or other user
*/
function isguestuser($user = null) {
global $USER, $DB, $CFG;
// make sure we have the user id cached in config table, because we are going to use it a lot
if (empty($CFG->siteguest)) {
if (!$guestid = $DB->get_field('user', 'id', array('username'=>'guest', 'mnethostid'=>$CFG->mnet_localhost_id))) {
// guest does not exist yet, weird
return false;
}
set_config('siteguest', $guestid);
}
if ($user === null) {
$user = $USER;
}
if ($user === null) {
// happens when setting the $USER
return false;
} else if (is_numeric($user)) {
return ($CFG->siteguest == $user);
} else if (is_object($user)) {
if (empty($user->id)) {
return false; // not logged in means is not be guest
} else {
return ($CFG->siteguest == $user->id);
}
} else {
throw new coding_exception('Invalid user parameter supplied for isguestuser() function!');
}
}
/**
* Does user have a (temporary or real) guest access to course?
*
* @category access
*
* @param context $context
* @param stdClass|int $user
* @return bool
*/
function is_guest(context $context, $user = null) {
global $USER;
// first find the course context
$coursecontext = $context->get_course_context();
// make sure there is a real user specified
if ($user === null) {
$userid = isset($USER->id) ? $USER->id : 0;
} else {
$userid = is_object($user) ? $user->id : $user;
}
if (isguestuser($userid)) {
// can not inspect or be enrolled
return true;
}
if (has_capability('moodle/course:view', $coursecontext, $user)) {
// viewing users appear out of nowhere, they are neither guests nor participants
return false;
}
// consider only real active enrolments here
if (is_enrolled($coursecontext, $user, '', true)) {
return false;
}
return true;
}
/**
* Returns true if the user has moodle/course:view capability in the course,
* this is intended for admins, managers (aka small admins), inspectors, etc.
*
* @category access
*
* @param context $context
* @param int|stdClass $user if null $USER is used
* @param string $withcapability extra capability name
* @return bool
*/
function is_viewing(context $context, $user = null, $withcapability = '') {
// first find the course context
$coursecontext = $context->get_course_context();
if (isguestuser($user)) {
// can not inspect
return false;
}
if (!has_capability('moodle/course:view', $coursecontext, $user)) {
// admins are allowed to inspect courses
return false;
}
if ($withcapability and !has_capability($withcapability, $context, $user)) {
// site admins always have the capability, but the enrolment above blocks
return false;
}
return true;
}
/**
* Returns true if the user is able to access the course.
*
* This function is in no way, shape, or form a substitute for require_login.
* It should only be used in circumstances where it is not possible to call require_login
* such as the navigation.
*
* This function checks many of the methods of access to a course such as the view
* capability, enrollments, and guest access. It also makes use of the cache
* generated by require_login for guest access.
*
* The flags within the $USER object that are used here should NEVER be used outside
* of this function can_access_course and require_login. Doing so WILL break future
* versions.
*
* @param stdClass $course record
* @param stdClass|int|null $user user record or id, current user if null
* @param string $withcapability Check for this capability as well.
* @param bool $onlyactive consider only active enrolments in enabled plugins and time restrictions
* @return boolean Returns true if the user is able to access the course
*/
function can_access_course(stdClass $course, $user = null, $withcapability = '', $onlyactive = false) {
global $DB, $USER;
// this function originally accepted $coursecontext parameter
if ($course instanceof context) {
if ($course instanceof context_course) {
debugging('deprecated context parameter, please use $course record');
$coursecontext = $course;
$course = $DB->get_record('course', array('id'=>$coursecontext->instanceid));
} else {
debugging('Invalid context parameter, please use $course record');
return false;
}
} else {
$coursecontext = context_course::instance($course->id);
}
if (!isset($USER->id)) {
// should never happen
$USER->id = 0;
debugging('Course access check being performed on a user with no ID.', DEBUG_DEVELOPER);
}
// make sure there is a user specified
if ($user === null) {
$userid = $USER->id;
} else {
$userid = is_object($user) ? $user->id : $user;
}
unset($user);
if ($withcapability and !has_capability($withcapability, $coursecontext, $userid)) {
return false;
}
if ($userid == $USER->id) {
if (!empty($USER->access['rsw'][$coursecontext->path])) {
// the fact that somebody switched role means they can access the course no matter to what role they switched
return true;
}
}
if (!$course->visible and !has_capability('moodle/course:viewhiddencourses', $coursecontext, $userid)) {
return false;
}
if (is_viewing($coursecontext, $userid)) {
return true;
}
if ($userid != $USER->id) {
// for performance reasons we do not verify temporary guest access for other users, sorry...
return is_enrolled($coursecontext, $userid, '', $onlyactive);
}
// === from here we deal only with $USER ===
$coursecontext->reload_if_dirty();
if (isset($USER->enrol['enrolled'][$course->id])) {
if ($USER->enrol['enrolled'][$course->id] > time()) {
return true;
}
}
if (isset($USER->enrol['tempguest'][$course->id])) {
if ($USER->enrol['tempguest'][$course->id] > time()) {
return true;
}
}
if (is_enrolled($coursecontext, $USER, '', $onlyactive)) {
return true;
}
if (!core_course_category::can_view_course_info($course)) {
// No guest access if user does not have capability to browse courses.
return false;
}
// if not enrolled try to gain temporary guest access
$instances = $DB->get_records('enrol', array('courseid'=>$course->id, 'status'=>ENROL_INSTANCE_ENABLED), 'sortorder, id ASC');
$enrols = enrol_get_plugins(true);
foreach ($instances as $instance) {
if (!isset($enrols[$instance->enrol])) {
continue;
}
// Get a duration for the guest access, a timestamp in the future, 0 (always) or false.
$until = $enrols[$instance->enrol]->try_guestaccess($instance);
if ($until !== false and $until > time()) {
$USER->enrol['tempguest'][$course->id] = $until;
return true;
}
}
if (isset($USER->enrol['tempguest'][$course->id])) {
unset($USER->enrol['tempguest'][$course->id]);
remove_temp_course_roles($coursecontext);
}
return false;
}
/**
* Loads the capability definitions for the component (from file).
*
* Loads the capability definitions for the component (from file). If no
* capabilities are defined for the component, we simply return an empty array.
*
* @access private
* @param string $component full plugin name, examples: 'moodle', 'mod_forum'
* @return array array of capabilities
*/
function load_capability_def($component) {
$defpath = core_component::get_component_directory($component).'/db/access.php';
$capabilities = array();
if (file_exists($defpath)) {
require($defpath);
if (!empty(${$component.'_capabilities'})) {
// BC capability array name
// since 2.0 we prefer $capabilities instead - it is easier to use and matches db/* files
debugging('componentname_capabilities array is deprecated, please use $capabilities array only in access.php files');
$capabilities = ${$component.'_capabilities'};
}
}
return $capabilities;
}
/**
* Gets the capabilities that have been cached in the database for this component.
*
* @access private
* @param string $component - examples: 'moodle', 'mod_forum'
* @return array array of capabilities
*/
function get_cached_capabilities($component = 'moodle') {
global $DB;
$caps = get_all_capabilities();
$componentcaps = array();
foreach ($caps as $cap) {
if ($cap['component'] == $component) {
$componentcaps[] = (object) $cap;
}
}
return $componentcaps;
}
/**
* Returns default capabilities for given role archetype.
*
* @param string $archetype role archetype
* @return array
*/
function get_default_capabilities($archetype) {
global $DB;
if (!$archetype) {
return array();
}
$alldefs = array();
$defaults = array();
$components = array();
$allcaps = get_all_capabilities();
foreach ($allcaps as $cap) {
if (!in_array($cap['component'], $components)) {
$components[] = $cap['component'];
$alldefs = array_merge($alldefs, load_capability_def($cap['component']));
}
}
foreach ($alldefs as $name=>$def) {
// Use array 'archetypes if available. Only if not specified, use 'legacy'.
if (isset($def['archetypes'])) {
if (isset($def['archetypes'][$archetype])) {
$defaults[$name] = $def['archetypes'][$archetype];
}
// 'legacy' is for backward compatibility with 1.9 access.php
} else {
if (isset($def['legacy'][$archetype])) {
$defaults[$name] = $def['legacy'][$archetype];
}
}
}
return $defaults;
}
/**
* Return default roles that can be assigned, overridden or switched
* by give role archetype.
*
* @param string $type assign|override|switch|view
* @param string $archetype
* @return array of role ids
*/
function get_default_role_archetype_allows($type, $archetype) {
global $DB;
if (empty($archetype)) {
return array();
}
$roles = $DB->get_records('role');
$archetypemap = array();
foreach ($roles as $role) {
if ($role->archetype) {
$archetypemap[$role->archetype][$role->id] = $role->id;
}
}
$defaults = array(
'assign' => array(
'manager' => array('manager', 'coursecreator', 'editingteacher', 'teacher', 'student'),
'coursecreator' => array(),
'editingteacher' => array('teacher', 'student'),
'teacher' => array(),
'student' => array(),
'guest' => array(),
'user' => array(),
'frontpage' => array(),
),
'override' => array(
'manager' => array('manager', 'coursecreator', 'editingteacher', 'teacher', 'student', 'guest', 'user', 'frontpage'),
'coursecreator' => array(),
'editingteacher' => array('teacher', 'student', 'guest'),
'teacher' => array(),
'student' => array(),
'guest' => array(),
'user' => array(),
'frontpage' => array(),
),
'switch' => array(
'manager' => array('editingteacher', 'teacher', 'student', 'guest'),
'coursecreator' => array(),
'editingteacher' => array('teacher', 'student', 'guest'),
'teacher' => array('student', 'guest'),
'student' => array(),
'guest' => array(),
'user' => array(),
'frontpage' => array(),
),
'view' => array(
'manager' => array('manager', 'coursecreator', 'editingteacher', 'teacher', 'student', 'guest', 'user', 'frontpage'),
'coursecreator' => array('coursecreator', 'editingteacher', 'teacher', 'student'),
'editingteacher' => array('coursecreator', 'editingteacher', 'teacher', 'student'),
'teacher' => array('coursecreator', 'editingteacher', 'teacher', 'student'),
'student' => array('coursecreator', 'editingteacher', 'teacher', 'student'),
'guest' => array(),
'user' => array(),
'frontpage' => array(),
),
);
if (!isset($defaults[$type][$archetype])) {
debugging("Unknown type '$type'' or archetype '$archetype''");
return array();
}
$return = array();
foreach ($defaults[$type][$archetype] as $at) {
if (isset($archetypemap[$at])) {
foreach ($archetypemap[$at] as $roleid) {
$return[$roleid] = $roleid;
}
}
}
return $return;
}
/**
* Reset role capabilities to default according to selected role archetype.
* If no archetype selected, removes all capabilities.
*
* This applies to capabilities that are assigned to the role (that you could
* edit in the 'define roles' interface), and not to any capability overrides
* in different locations.
*
* @param int $roleid ID of role to reset capabilities for
*/
function reset_role_capabilities($roleid) {
global $DB;
$role = $DB->get_record('role', array('id'=>$roleid), '*', MUST_EXIST);
$defaultcaps = get_default_capabilities($role->archetype);
$systemcontext = context_system::instance();
$DB->delete_records('role_capabilities',
array('roleid' => $roleid, 'contextid' => $systemcontext->id));
foreach ($defaultcaps as $cap=>$permission) {
assign_capability($cap, $permission, $roleid, $systemcontext->id);
}
// Reset any cache of this role, including MUC.
accesslib_clear_role_cache($roleid);
}
/**
* Updates the capabilities table with the component capability definitions.
* If no parameters are given, the function updates the core moodle
* capabilities.
*
* Note that the absence of the db/access.php capabilities definition file
* will cause any stored capabilities for the component to be removed from
* the database.
*
* @access private
* @param string $component examples: 'moodle', 'mod_forum', 'block_quiz_results'
* @return boolean true if success, exception in case of any problems
*/
function update_capabilities($component = 'moodle') {
global $DB, $OUTPUT;
$storedcaps = array();
$filecaps = load_capability_def($component);
foreach ($filecaps as $capname=>$unused) {
if (!preg_match('|^[a-z]+/[a-z_0-9]+:[a-z_0-9]+$|', $capname)) {
debugging("Coding problem: Invalid capability name '$capname', use 'clonepermissionsfrom' field for migration.");
}
}
// It is possible somebody directly modified the DB (according to accesslib_test anyway).
// So ensure our updating is based on fresh data.
cache::make('core', 'capabilities')->delete('core_capabilities');
$cachedcaps = get_cached_capabilities($component);
if ($cachedcaps) {
foreach ($cachedcaps as $cachedcap) {
array_push($storedcaps, $cachedcap->name);
// update risk bitmasks and context levels in existing capabilities if needed
if (array_key_exists($cachedcap->name, $filecaps)) {
if (!array_key_exists('riskbitmask', $filecaps[$cachedcap->name])) {
$filecaps[$cachedcap->name]['riskbitmask'] = 0; // no risk if not specified
}
if ($cachedcap->captype != $filecaps[$cachedcap->name]['captype']) {
$updatecap = new stdClass();
$updatecap->id = $cachedcap->id;
$updatecap->captype = $filecaps[$cachedcap->name]['captype'];
$DB->update_record('capabilities', $updatecap);
}
if ($cachedcap->riskbitmask != $filecaps[$cachedcap->name]['riskbitmask']) {
$updatecap = new stdClass();
$updatecap->id = $cachedcap->id;
$updatecap->riskbitmask = $filecaps[$cachedcap->name]['riskbitmask'];
$DB->update_record('capabilities', $updatecap);
}
if (!array_key_exists('contextlevel', $filecaps[$cachedcap->name])) {
$filecaps[$cachedcap->name]['contextlevel'] = 0; // no context level defined
}
if ($cachedcap->contextlevel != $filecaps[$cachedcap->name]['contextlevel']) {
$updatecap = new stdClass();
$updatecap->id = $cachedcap->id;
$updatecap->contextlevel = $filecaps[$cachedcap->name]['contextlevel'];
$DB->update_record('capabilities', $updatecap);
}
}
}
}
// Flush the cached again, as we have changed DB.
cache::make('core', 'capabilities')->delete('core_capabilities');
// Are there new capabilities in the file definition?
$newcaps = array();
foreach ($filecaps as $filecap => $def) {
if (!$storedcaps ||
($storedcaps && in_array($filecap, $storedcaps) === false)) {
if (!array_key_exists('riskbitmask', $def)) {
$def['riskbitmask'] = 0; // no risk if not specified
}
$newcaps[$filecap] = $def;
}
}
// Add new capabilities to the stored definition.
$existingcaps = $DB->get_records_menu('capabilities', array(), 'id', 'id, name');
foreach ($newcaps as $capname => $capdef) {
$capability = new stdClass();
$capability->name = $capname;
$capability->captype = $capdef['captype'];
$capability->contextlevel = $capdef['contextlevel'];
$capability->component = $component;
$capability->riskbitmask = $capdef['riskbitmask'];
$DB->insert_record('capabilities', $capability, false);
// Flush the cached, as we have changed DB.
cache::make('core', 'capabilities')->delete('core_capabilities');
if (isset($capdef['clonepermissionsfrom']) && in_array($capdef['clonepermissionsfrom'], $existingcaps)){
if ($rolecapabilities = $DB->get_records('role_capabilities', array('capability'=>$capdef['clonepermissionsfrom']))){
foreach ($rolecapabilities as $rolecapability){
//assign_capability will update rather than insert if capability exists
if (!assign_capability($capname, $rolecapability->permission,
$rolecapability->roleid, $rolecapability->contextid, true)){
echo $OUTPUT->notification('Could not clone capabilities for '.$capname);
}
}
}
// we ignore archetype key if we have cloned permissions
} else if (isset($capdef['archetypes']) && is_array($capdef['archetypes'])) {
assign_legacy_capabilities($capname, $capdef['archetypes']);
// 'legacy' is for backward compatibility with 1.9 access.php
} else if (isset($capdef['legacy']) && is_array($capdef['legacy'])) {
assign_legacy_capabilities($capname, $capdef['legacy']);
}
}
// Are there any capabilities that have been removed from the file
// definition that we need to delete from the stored capabilities and
// role assignments?
capabilities_cleanup($component, $filecaps);
// reset static caches
accesslib_reset_role_cache();
// Flush the cached again, as we have changed DB.
cache::make('core', 'capabilities')->delete('core_capabilities');
return true;
}
/**
* Deletes cached capabilities that are no longer needed by the component.
* Also unassigns these capabilities from any roles that have them.
* NOTE: this function is called from lib/db/upgrade.php
*
* @access private
* @param string $component examples: 'moodle', 'mod_forum', 'block_quiz_results'
* @param array $newcapdef array of the new capability definitions that will be
* compared with the cached capabilities
* @return int number of deprecated capabilities that have been removed
*/
function capabilities_cleanup($component, $newcapdef = null) {
global $DB;
$removedcount = 0;
if ($cachedcaps = get_cached_capabilities($component)) {
foreach ($cachedcaps as $cachedcap) {
if (empty($newcapdef) ||
array_key_exists($cachedcap->name, $newcapdef) === false) {
// Delete from roles.
if ($roles = get_roles_with_capability($cachedcap->name)) {
foreach ($roles as $role) {
if (!unassign_capability($cachedcap->name, $role->id)) {
print_error('cannotunassigncap', 'error', '', (object)array('cap'=>$cachedcap->name, 'role'=>$role->name));
}
}
}
// Remove from role_capabilities for any old ones.
$DB->delete_records('role_capabilities', array('capability' => $cachedcap->name));
// Remove from capabilities cache.
$DB->delete_records('capabilities', array('name' => $cachedcap->name));
$removedcount++;
} // End if.
}
}
if ($removedcount) {
cache::make('core', 'capabilities')->delete('core_capabilities');
}
return $removedcount;
}
/**
* Returns an array of all the known types of risk
* The array keys can be used, for example as CSS class names, or in calls to
* print_risk_icon. The values are the corresponding RISK_ constants.
*
* @return array all the known types of risk.
*/
function get_all_risks() {
return array(
'riskmanagetrust' => RISK_MANAGETRUST,
'riskconfig' => RISK_CONFIG,
'riskxss' => RISK_XSS,
'riskpersonal' => RISK_PERSONAL,
'riskspam' => RISK_SPAM,
'riskdataloss' => RISK_DATALOSS,
);
}
/**
* Return a link to moodle docs for a given capability name
*
* @param stdClass $capability a capability - a row from the mdl_capabilities table.
* @return string the human-readable capability name as a link to Moodle Docs.
*/
function get_capability_docs_link($capability) {
$url = get_docs_url('Capabilities/' . $capability->name);
return '<a onclick="this.target=\'docspopup\'" href="' . $url . '">' . get_capability_string($capability->name) . '</a>';
}
/**
* This function pulls out all the resolved capabilities (overrides and
* defaults) of a role used in capability overrides in contexts at a given
* context.
*
* @param int $roleid
* @param context $context
* @param string $cap capability, optional, defaults to ''
* @return array Array of capabilities
*/
function role_context_capabilities($roleid, context $context, $cap = '') {
global $DB;
$contexts = $context->get_parent_context_ids(true);
$contexts = '('.implode(',', $contexts).')';
$params = array($roleid);
if ($cap) {
$search = " AND rc.capability = ? ";
$params[] = $cap;
} else {
$search = '';
}
$sql = "SELECT rc.*
FROM {role_capabilities} rc
JOIN {context} c ON rc.contextid = c.id
JOIN {capabilities} cap ON rc.capability = cap.name
WHERE rc.contextid in $contexts
AND rc.roleid = ?
$search
ORDER BY c.contextlevel DESC, rc.capability DESC";
$capabilities = array();
if ($records = $DB->get_records_sql($sql, $params)) {
// We are traversing via reverse order.
foreach ($records as $record) {
// If not set yet (i.e. inherit or not set at all), or currently we have a prohibit
if (!isset($capabilities[$record->capability]) || $record->permission<-500) {
$capabilities[$record->capability] = $record->permission;
}
}
}
return $capabilities;
}
/**
* Constructs array with contextids as first parameter and context paths,
* in both cases bottom top including self.
*
* @access private
* @param context $context
* @return array
*/
function get_context_info_list(context $context) {
$contextids = explode('/', ltrim($context->path, '/'));
$contextpaths = array();
$contextids2 = $contextids;
while ($contextids2) {
$contextpaths[] = '/' . implode('/', $contextids2);
array_pop($contextids2);
}
return array($contextids, $contextpaths);
}
/**
* Check if context is the front page context or a context inside it
*
* Returns true if this context is the front page context, or a context inside it,
* otherwise false.
*
* @param context $context a context object.
* @return bool
*/
function is_inside_frontpage(context $context) {
$frontpagecontext = context_course::instance(SITEID);
return strpos($context->path . '/', $frontpagecontext->path . '/') === 0;
}
/**
* Returns capability information (cached)
*
* @param string $capabilityname
* @return stdClass or null if capability not found
*/
function get_capability_info($capabilityname) {
$caps = get_all_capabilities();
if (!isset($caps[$capabilityname])) {
return null;
}
return (object) $caps[$capabilityname];
}
/**
* Returns all capabilitiy records, preferably from MUC and not database.
*
* @return array All capability records indexed by capability name
*/
function get_all_capabilities() {
global $DB;
$cache = cache::make('core', 'capabilities');
if (!$allcaps = $cache->get('core_capabilities')) {
$rs = $DB->get_recordset('capabilities');
$allcaps = array();
foreach ($rs as $capability) {
$capability->riskbitmask = (int) $capability->riskbitmask;
$allcaps[$capability->name] = (array) $capability;
}
$rs->close();
$cache->set('core_capabilities', $allcaps);
}
return $allcaps;
}
/**
* Returns the human-readable, translated version of the capability.
* Basically a big switch statement.
*
* @param string $capabilityname e.g. mod/choice:readresponses
* @return string
*/
function get_capability_string($capabilityname) {
// Typical capability name is 'plugintype/pluginname:capabilityname'
list($type, $name, $capname) = preg_split('|[/:]|', $capabilityname);
if ($type === 'moodle') {
$component = 'core_role';
} else if ($type === 'quizreport') {
//ugly hack!!
$component = 'quiz_'.$name;
} else {
$component = $type.'_'.$name;
}
$stringname = $name.':'.$capname;
if ($component === 'core_role' or get_string_manager()->string_exists($stringname, $component)) {
return get_string($stringname, $component);
}
$dir = core_component::get_component_directory($component);
if (!file_exists($dir)) {
// plugin broken or does not exist, do not bother with printing of debug message
return $capabilityname.' ???';
}
// something is wrong in plugin, better print debug
return get_string($stringname, $component);
}
/**
* This gets the mod/block/course/core etc strings.
*
* @param string $component
* @param int $contextlevel
* @return string|bool String is success, false if failed
*/
function get_component_string($component, $contextlevel) {
if ($component === 'moodle' || $component === 'core') {
return context_helper::get_level_name($contextlevel);
}
list($type, $name) = core_component::normalize_component($component);
$dir = core_component::get_plugin_directory($type, $name);
if (!file_exists($dir)) {
// plugin not installed, bad luck, there is no way to find the name
return $component . ' ???';
}
// Some plugin types need an extra prefix to make the name easy to understand.
switch ($type) {
case 'quiz':
$prefix = get_string('quizreport', 'quiz') . ': ';
break;
case 'repository':
$prefix = get_string('repository', 'repository') . ': ';
break;
case 'gradeimport':
$prefix = get_string('gradeimport', 'grades') . ': ';
break;
case 'gradeexport':
$prefix = get_string('gradeexport', 'grades') . ': ';
break;
case 'gradereport':
$prefix = get_string('gradereport', 'grades') . ': ';
break;
case 'webservice':
$prefix = get_string('webservice', 'webservice') . ': ';
break;
case 'block':
$prefix = get_string('block') . ': ';
break;
case 'mod':
$prefix = get_string('activity') . ': ';
break;
// Default case, just use the plugin name.
default:
$prefix = '';
}
return $prefix . get_string('pluginname', $component);
}
/**
* Gets the list of roles assigned to this context and up (parents)
* from the aggregation of:
* a) the list of roles that are visible on user profile page and participants page (profileroles setting) and;
* b) if applicable, those roles that are assigned in the context.
*
* @param context $context
* @return array
*/
function get_profile_roles(context $context) {
global $CFG, $DB;
// If the current user can assign roles, then they can see all roles on the profile and participants page,
// provided the roles are assigned to at least 1 user in the context. If not, only the policy-defined roles.
if (has_capability('moodle/role:assign', $context)) {
$rolesinscope = array_keys(get_all_roles($context));
} else {
$rolesinscope = empty($CFG->profileroles) ? [] : array_map('trim', explode(',', $CFG->profileroles));
}
if (empty($rolesinscope)) {
return [];
}
list($rallowed, $params) = $DB->get_in_or_equal($rolesinscope, SQL_PARAMS_NAMED, 'a');
list($contextlist, $cparams) = $DB->get_in_or_equal($context->get_parent_context_ids(true), SQL_PARAMS_NAMED, 'p');
$params = array_merge($params, $cparams);
if ($coursecontext = $context->get_course_context(false)) {
$params['coursecontext'] = $coursecontext->id;
} else {
$params['coursecontext'] = 0;
}
$sql = "SELECT DISTINCT r.id, r.name, r.shortname, r.sortorder, rn.name AS coursealias
FROM {role_assignments} ra, {role} r
LEFT JOIN {role_names} rn ON (rn.contextid = :coursecontext AND rn.roleid = r.id)
WHERE r.id = ra.roleid
AND ra.contextid $contextlist
AND r.id $rallowed
ORDER BY r.sortorder ASC";
return $DB->get_records_sql($sql, $params);
}
/**
* Gets the list of roles assigned to this context and up (parents)
*
* @param context $context
* @param boolean $includeparents, false means without parents.
* @return array
*/
function get_roles_used_in_context(context $context, $includeparents = true) {
global $DB;
if ($includeparents === true) {
list($contextlist, $params) = $DB->get_in_or_equal($context->get_parent_context_ids(true), SQL_PARAMS_NAMED, 'cl');
} else {
list($contextlist, $params) = $DB->get_in_or_equal($context->id, SQL_PARAMS_NAMED, 'cl');
}
if ($coursecontext = $context->get_course_context(false)) {
$params['coursecontext'] = $coursecontext->id;
} else {
$params['coursecontext'] = 0;
}
$sql = "SELECT DISTINCT r.id, r.name, r.shortname, r.sortorder, rn.name AS coursealias
FROM {role_assignments} ra, {role} r
LEFT JOIN {role_names} rn ON (rn.contextid = :coursecontext AND rn.roleid = r.id)
WHERE r.id = ra.roleid
AND ra.contextid $contextlist
ORDER BY r.sortorder ASC";
return $DB->get_records_sql($sql, $params);
}
/**
* This function is used to print roles column in user profile page.
* It is using the CFG->profileroles to limit the list to only interesting roles.
* (The permission tab has full details of user role assignments.)
*
* @param int $userid
* @param int $courseid
* @return string
*/
function get_user_roles_in_course($userid, $courseid) {
global $CFG, $DB;
if ($courseid == SITEID) {
$context = context_system::instance();
} else {
$context = context_course::instance($courseid);
}
// If the current user can assign roles, then they can see all roles on the profile and participants page,
// provided the roles are assigned to at least 1 user in the context. If not, only the policy-defined roles.
if (has_capability('moodle/role:assign', $context)) {
$rolesinscope = array_keys(get_all_roles($context));
} else {
$rolesinscope = empty($CFG->profileroles) ? [] : array_map('trim', explode(',', $CFG->profileroles));
}
if (empty($rolesinscope)) {
return '';
}
list($rallowed, $params) = $DB->get_in_or_equal($rolesinscope, SQL_PARAMS_NAMED, 'a');
list($contextlist, $cparams) = $DB->get_in_or_equal($context->get_parent_context_ids(true), SQL_PARAMS_NAMED, 'p');
$params = array_merge($params, $cparams);
if ($coursecontext = $context->get_course_context(false)) {
$params['coursecontext'] = $coursecontext->id;
} else {
$params['coursecontext'] = 0;
}
$sql = "SELECT DISTINCT r.id, r.name, r.shortname, r.sortorder, rn.name AS coursealias
FROM {role_assignments} ra, {role} r
LEFT JOIN {role_names} rn ON (rn.contextid = :coursecontext AND rn.roleid = r.id)
WHERE r.id = ra.roleid
AND ra.contextid $contextlist
AND r.id $rallowed
AND ra.userid = :userid
ORDER BY r.sortorder ASC";
$params['userid'] = $userid;
$rolestring = '';
if ($roles = $DB->get_records_sql($sql, $params)) {
$viewableroles = get_viewable_roles($context, $userid);
$rolenames = array();
foreach ($roles as $roleid => $unused) {
if (isset($viewableroles[$roleid])) {
$url = new moodle_url('/user/index.php', ['contextid' => $context->id, 'roleid' => $roleid]);
$rolenames[] = '<a href="' . $url . '">' . $viewableroles[$roleid] . '</a>';
}
}
$rolestring = implode(',', $rolenames);
}
return $rolestring;
}
/**
* Checks if a user can assign users to a particular role in this context
*
* @param context $context
* @param int $targetroleid - the id of the role you want to assign users to
* @return boolean
*/
function user_can_assign(context $context, $targetroleid) {
global $DB;
// First check to see if the user is a site administrator.
if (is_siteadmin()) {
return true;
}
// Check if user has override capability.
// If not return false.
if (!has_capability('moodle/role:assign', $context)) {
return false;
}
// pull out all active roles of this user from this context(or above)
if ($userroles = get_user_roles($context)) {
foreach ($userroles as $userrole) {
// if any in the role_allow_override table, then it's ok
if ($DB->get_record('role_allow_assign', array('roleid'=>$userrole->roleid, 'allowassign'=>$targetroleid))) {
return true;
}
}
}
return false;
}
/**
* Returns all site roles in correct sort order.
*
* Note: this method does not localise role names or descriptions,
* use role_get_names() if you need role names.
*
* @param context $context optional context for course role name aliases
* @return array of role records with optional coursealias property
*/
function get_all_roles(context $context = null) {
global $DB;
if (!$context or !$coursecontext = $context->get_course_context(false)) {
$coursecontext = null;
}
if ($coursecontext) {
$sql = "SELECT r.*, rn.name AS coursealias
FROM {role} r
LEFT JOIN {role_names} rn ON (rn.contextid = :coursecontext AND rn.roleid = r.id)
ORDER BY r.sortorder ASC";
return $DB->get_records_sql($sql, array('coursecontext'=>$coursecontext->id));
} else {
return $DB->get_records('role', array(), 'sortorder ASC');
}
}
/**
* Returns roles of a specified archetype
*
* @param string $archetype
* @return array of full role records
*/
function get_archetype_roles($archetype) {
global $DB;
return $DB->get_records('role', array('archetype'=>$archetype), 'sortorder ASC');
}
/**
* Gets all the user roles assigned in this context, or higher contexts for a list of users.
*
* If you try using the combination $userids = [], $checkparentcontexts = true then this is likely
* to cause an out-of-memory error on large Moodle sites, so this combination is deprecated and
* outputs a warning, even though it is the default.
*
* @param context $context
* @param array $userids. An empty list means fetch all role assignments for the context.
* @param bool $checkparentcontexts defaults to true
* @param string $order defaults to 'c.contextlevel DESC, r.sortorder ASC'
* @return array
*/
function get_users_roles(context $context, $userids = [], $checkparentcontexts = true, $order = 'c.contextlevel DESC, r.sortorder ASC') {
global $DB;
if (!$userids && $checkparentcontexts) {
debugging('Please do not call get_users_roles() with $checkparentcontexts = true ' .
'and $userids array not set. This combination causes large Moodle sites ' .
'with lots of site-wide role assignemnts to run out of memory.', DEBUG_DEVELOPER);
}
if ($checkparentcontexts) {
$contextids = $context->get_parent_context_ids();
} else {
$contextids = array();
}
$contextids[] = $context->id;
list($contextids, $params) = $DB->get_in_or_equal($contextids, SQL_PARAMS_NAMED, 'con');
// If userids was passed as an empty array, we fetch all role assignments for the course.
if (empty($userids)) {
$useridlist = ' IS NOT NULL ';
$uparams = [];
} else {
list($useridlist, $uparams) = $DB->get_in_or_equal($userids, SQL_PARAMS_NAMED, 'uids');
}
$sql = "SELECT ra.*, r.name, r.shortname, ra.userid
FROM {role_assignments} ra, {role} r, {context} c
WHERE ra.userid $useridlist
AND ra.roleid = r.id
AND ra.contextid = c.id
AND ra.contextid $contextids
ORDER BY $order";
$all = $DB->get_records_sql($sql , array_merge($params, $uparams));
// Return results grouped by userid.
$result = [];
foreach ($all as $id => $record) {
if (!isset($result[$record->userid])) {
$result[$record->userid] = [];
}
$result[$record->userid][$record->id] = $record;
}
// Make sure all requested users are included in the result, even if they had no role assignments.
foreach ($userids as $id) {
if (!isset($result[$id])) {
$result[$id] = [];
}
}
return $result;
}
/**
* Gets all the user roles assigned in this context, or higher contexts
* this is mainly used when checking if a user can assign a role, or overriding a role
* i.e. we need to know what this user holds, in order to verify against allow_assign and
* allow_override tables
*
* @param context $context
* @param int $userid
* @param bool $checkparentcontexts defaults to true
* @param string $order defaults to 'c.contextlevel DESC, r.sortorder ASC'
* @return array
*/
function get_user_roles(context $context, $userid = 0, $checkparentcontexts = true, $order = 'c.contextlevel DESC, r.sortorder ASC') {
global $USER, $DB;
if (empty($userid)) {
if (empty($USER->id)) {
return array();
}
$userid = $USER->id;
}
if ($checkparentcontexts) {
$contextids = $context->get_parent_context_ids();
} else {
$contextids = array();
}
$contextids[] = $context->id;
list($contextids, $params) = $DB->get_in_or_equal($contextids, SQL_PARAMS_QM);
array_unshift($params, $userid);
$sql = "SELECT ra.*, r.name, r.shortname
FROM {role_assignments} ra, {role} r, {context} c
WHERE ra.userid = ?
AND ra.roleid = r.id
AND ra.contextid = c.id
AND ra.contextid $contextids
ORDER BY $order";
return $DB->get_records_sql($sql ,$params);
}
/**
* Like get_user_roles, but adds in the authenticated user role, and the front
* page roles, if applicable.
*
* @param context $context the context.
* @param int $userid optional. Defaults to $USER->id
* @return array of objects with fields ->userid, ->contextid and ->roleid.
*/
function get_user_roles_with_special(context $context, $userid = 0) {
global $CFG, $USER;
if (empty($userid)) {
if (empty($USER->id)) {
return array();
}
$userid = $USER->id;
}
$ras = get_user_roles($context, $userid);
// Add front-page role if relevant.
$defaultfrontpageroleid = isset($CFG->defaultfrontpageroleid) ? $CFG->defaultfrontpageroleid : 0;
$isfrontpage = ($context->contextlevel == CONTEXT_COURSE && $context->instanceid == SITEID) ||
is_inside_frontpage($context);
if ($defaultfrontpageroleid && $isfrontpage) {
$frontpagecontext = context_course::instance(SITEID);
$ra = new stdClass();
$ra->userid = $userid;
$ra->contextid = $frontpagecontext->id;
$ra->roleid = $defaultfrontpageroleid;
$ras[] = $ra;
}
// Add authenticated user role if relevant.
$defaultuserroleid = isset($CFG->defaultuserroleid) ? $CFG->defaultuserroleid : 0;
if ($defaultuserroleid && !isguestuser($userid)) {
$systemcontext = context_system::instance();
$ra = new stdClass();
$ra->userid = $userid;
$ra->contextid = $systemcontext->id;
$ra->roleid = $defaultuserroleid;
$ras[] = $ra;
}
return $ras;
}
/**
* Creates a record in the role_allow_override table
*
* @param int $fromroleid source roleid
* @param int $targetroleid target roleid
* @return void
*/
function core_role_set_override_allowed($fromroleid, $targetroleid) {
global $DB;
$record = new stdClass();
$record->roleid = $fromroleid;
$record->allowoverride = $targetroleid;
$DB->insert_record('role_allow_override', $record);
}
/**
* Creates a record in the role_allow_assign table
*
* @param int $fromroleid source roleid
* @param int $targetroleid target roleid
* @return void
*/
function core_role_set_assign_allowed($fromroleid, $targetroleid) {
global $DB;
$record = new stdClass();
$record->roleid = $fromroleid;
$record->allowassign = $targetroleid;
$DB->insert_record('role_allow_assign', $record);
}
/**
* Creates a record in the role_allow_switch table
*
* @param int $fromroleid source roleid
* @param int $targetroleid target roleid
* @return void
*/
function core_role_set_switch_allowed($fromroleid, $targetroleid) {
global $DB;
$record = new stdClass();
$record->roleid = $fromroleid;
$record->allowswitch = $targetroleid;
$DB->insert_record('role_allow_switch', $record);
}
/**
* Creates a record in the role_allow_view table
*
* @param int $fromroleid source roleid
* @param int $targetroleid target roleid
* @return void
*/
function core_role_set_view_allowed($fromroleid, $targetroleid) {
global $DB;
$record = new stdClass();
$record->roleid = $fromroleid;
$record->allowview = $targetroleid;
$DB->insert_record('role_allow_view', $record);
}
/**
* Gets a list of roles that this user can assign in this context
*
* @param context $context the context.
* @param int $rolenamedisplay the type of role name to display. One of the
* ROLENAME_X constants. Default ROLENAME_ALIAS.
* @param bool $withusercounts if true, count the number of users with each role.
* @param integer|object $user A user id or object. By default (null) checks the permissions of the current user.
* @return array if $withusercounts is false, then an array $roleid => $rolename.
* if $withusercounts is true, returns a list of three arrays,
* $rolenames, $rolecounts, and $nameswithcounts.
*/
function get_assignable_roles(context $context, $rolenamedisplay = ROLENAME_ALIAS, $withusercounts = false, $user = null) {
global $USER, $DB;
// make sure there is a real user specified
if ($user === null) {
$userid = isset($USER->id) ? $USER->id : 0;
} else {
$userid = is_object($user) ? $user->id : $user;
}
if (!has_capability('moodle/role:assign', $context, $userid)) {
if ($withusercounts) {
return array(array(), array(), array());
} else {
return array();
}
}
$params = array();
$extrafields = '';
if ($withusercounts) {
$extrafields = ', (SELECT COUNT(DISTINCT u.id)
FROM {role_assignments} cra JOIN {user} u ON cra.userid = u.id
WHERE cra.roleid = r.id AND cra.contextid = :conid AND u.deleted = 0
) AS usercount';
$params['conid'] = $context->id;
}
if (is_siteadmin($userid)) {
// show all roles allowed in this context to admins
$assignrestriction = "";
} else {
$parents = $context->get_parent_context_ids(true);
$contexts = implode(',' , $parents);
$assignrestriction = "JOIN (SELECT DISTINCT raa.allowassign AS id
FROM {role_allow_assign} raa
JOIN {role_assignments} ra ON ra.roleid = raa.roleid
WHERE ra.userid = :userid AND ra.contextid IN ($contexts)
) ar ON ar.id = r.id";
$params['userid'] = $userid;
}
$params['contextlevel'] = $context->contextlevel;
if ($coursecontext = $context->get_course_context(false)) {
$params['coursecontext'] = $coursecontext->id;
} else {
$params['coursecontext'] = 0; // no course aliases
$coursecontext = null;
}
$sql = "SELECT r.id, r.name, r.shortname, rn.name AS coursealias $extrafields
FROM {role} r
$assignrestriction
JOIN {role_context_levels} rcl ON (rcl.contextlevel = :contextlevel AND r.id = rcl.roleid)
LEFT JOIN {role_names} rn ON (rn.contextid = :coursecontext AND rn.roleid = r.id)
ORDER BY r.sortorder ASC";
$roles = $DB->get_records_sql($sql, $params);
$rolenames = role_fix_names($roles, $coursecontext, $rolenamedisplay, true);
if (!$withusercounts) {
return $rolenames;
}
$rolecounts = array();
$nameswithcounts = array();
foreach ($roles as $role) {
$nameswithcounts[$role->id] = $rolenames[$role->id] . ' (' . $roles[$role->id]->usercount . ')';
$rolecounts[$role->id] = $roles[$role->id]->usercount;
}
return array($rolenames, $rolecounts, $nameswithcounts);
}
/**
* Gets a list of roles that this user can switch to in a context
*
* Gets a list of roles that this user can switch to in a context, for the switchrole menu.
* This function just process the contents of the role_allow_switch table. You also need to
* test the moodle/role:switchroles to see if the user is allowed to switch in the first place.
*
* @param context $context a context.
* @return array an array $roleid => $rolename.
*/
function get_switchable_roles(context $context) {
global $USER, $DB;
// You can't switch roles without this capability.
if (!has_capability('moodle/role:switchroles', $context)) {
return [];
}
$params = array();
$extrajoins = '';
$extrawhere = '';
if (!is_siteadmin()) {
// Admins are allowed to switch to any role with.
// Others are subject to the additional constraint that the switch-to role must be allowed by
// 'role_allow_switch' for some role they have assigned in this context or any parent.
$parents = $context->get_parent_context_ids(true);
$contexts = implode(',' , $parents);
$extrajoins = "JOIN {role_allow_switch} ras ON ras.allowswitch = rc.roleid
JOIN {role_assignments} ra ON ra.roleid = ras.roleid";
$extrawhere = "WHERE ra.userid = :userid AND ra.contextid IN ($contexts)";
$params['userid'] = $USER->id;
}
if ($coursecontext = $context->get_course_context(false)) {
$params['coursecontext'] = $coursecontext->id;
} else {
$params['coursecontext'] = 0; // no course aliases
$coursecontext = null;
}
$query = "
SELECT r.id, r.name, r.shortname, rn.name AS coursealias
FROM (SELECT DISTINCT rc.roleid
FROM {role_capabilities} rc
$extrajoins
$extrawhere) idlist
JOIN {role} r ON r.id = idlist.roleid
LEFT JOIN {role_names} rn ON (rn.contextid = :coursecontext AND rn.roleid = r.id)
ORDER BY r.sortorder";
$roles = $DB->get_records_sql($query, $params);
return role_fix_names($roles, $context, ROLENAME_ALIAS, true);
}
/**
* Gets a list of roles that this user can view in a context
*
* @param context $context a context.
* @param int $userid id of user.
* @return array an array $roleid => $rolename.
*/
function get_viewable_roles(context $context, $userid = null) {
global $USER, $DB;
if ($userid == null) {
$userid = $USER->id;
}
$params = array();
$extrajoins = '';
$extrawhere = '';
if (!is_siteadmin()) {
// Admins are allowed to view any role.
// Others are subject to the additional constraint that the view role must be allowed by
// 'role_allow_view' for some role they have assigned in this context or any parent.
$contexts = $context->get_parent_context_ids(true);
list($insql, $inparams) = $DB->get_in_or_equal($contexts, SQL_PARAMS_NAMED);
$extrajoins = "JOIN {role_allow_view} ras ON ras.allowview = r.id
JOIN {role_assignments} ra ON ra.roleid = ras.roleid";
$extrawhere = "WHERE ra.userid = :userid AND ra.contextid $insql";
$params += $inparams;
$params['userid'] = $userid;
}
if ($coursecontext = $context->get_course_context(false)) {
$params['coursecontext'] = $coursecontext->id;
} else {
$params['coursecontext'] = 0; // No course aliases.
$coursecontext = null;
}
$query = "
SELECT r.id, r.name, r.shortname, rn.name AS coursealias, r.sortorder
FROM {role} r
$extrajoins
LEFT JOIN {role_names} rn ON (rn.contextid = :coursecontext AND rn.roleid = r.id)
$extrawhere
GROUP BY r.id, r.name, r.shortname, rn.name, r.sortorder
ORDER BY r.sortorder";
$roles = $DB->get_records_sql($query, $params);
return role_fix_names($roles, $context, ROLENAME_ALIAS, true);
}
/**
* Gets a list of roles that this user can override in this context.
*
* @param context $context the context.
* @param int $rolenamedisplay the type of role name to display. One of the
* ROLENAME_X constants. Default ROLENAME_ALIAS.
* @param bool $withcounts if true, count the number of overrides that are set for each role.
* @return array if $withcounts is false, then an array $roleid => $rolename.
* if $withusercounts is true, returns a list of three arrays,
* $rolenames, $rolecounts, and $nameswithcounts.
*/
function get_overridable_roles(context $context, $rolenamedisplay = ROLENAME_ALIAS, $withcounts = false) {
global $USER, $DB;
if (!has_any_capability(array('moodle/role:safeoverride', 'moodle/role:override'), $context)) {
if ($withcounts) {
return array(array(), array(), array());
} else {
return array();
}
}
$parents = $context->get_parent_context_ids(true);
$contexts = implode(',' , $parents);
$params = array();
$extrafields = '';
$params['userid'] = $USER->id;
if ($withcounts) {
$extrafields = ', (SELECT COUNT(rc.id) FROM {role_capabilities} rc
WHERE rc.roleid = ro.id AND rc.contextid = :conid) AS overridecount';
$params['conid'] = $context->id;
}
if ($coursecontext = $context->get_course_context(false)) {
$params['coursecontext'] = $coursecontext->id;
} else {
$params['coursecontext'] = 0; // no course aliases
$coursecontext = null;
}
if (is_siteadmin()) {
// show all roles to admins
$roles = $DB->get_records_sql("
SELECT ro.id, ro.name, ro.shortname, rn.name AS coursealias $extrafields
FROM {role} ro
LEFT JOIN {role_names} rn ON (rn.contextid = :coursecontext AND rn.roleid = ro.id)
ORDER BY ro.sortorder ASC", $params);
} else {
$roles = $DB->get_records_sql("
SELECT ro.id, ro.name, ro.shortname, rn.name AS coursealias $extrafields
FROM {role} ro
JOIN (SELECT DISTINCT r.id
FROM {role} r
JOIN {role_allow_override} rao ON r.id = rao.allowoverride
JOIN {role_assignments} ra ON rao.roleid = ra.roleid
WHERE ra.userid = :userid AND ra.contextid IN ($contexts)
) inline_view ON ro.id = inline_view.id
LEFT JOIN {role_names} rn ON (rn.contextid = :coursecontext AND rn.roleid = ro.id)
ORDER BY ro.sortorder ASC", $params);
}
$rolenames = role_fix_names($roles, $context, $rolenamedisplay, true);
if (!$withcounts) {
return $rolenames;
}
$rolecounts = array();
$nameswithcounts = array();
foreach ($roles as $role) {
$nameswithcounts[$role->id] = $rolenames[$role->id] . ' (' . $roles[$role->id]->overridecount . ')';
$rolecounts[$role->id] = $roles[$role->id]->overridecount;
}
return array($rolenames, $rolecounts, $nameswithcounts);
}
/**
* Create a role menu suitable for default role selection in enrol plugins.
*
* @package core_enrol
*
* @param context $context
* @param int $addroleid current or default role - always added to list
* @return array roleid=>localised role name
*/
function get_default_enrol_roles(context $context, $addroleid = null) {
global $DB;
$params = array('contextlevel'=>CONTEXT_COURSE);
if ($coursecontext = $context->get_course_context(false)) {
$params['coursecontext'] = $coursecontext->id;
} else {
$params['coursecontext'] = 0; // no course names
$coursecontext = null;
}
if ($addroleid) {
$addrole = "OR r.id = :addroleid";
$params['addroleid'] = $addroleid;
} else {
$addrole = "";
}
$sql = "SELECT r.id, r.name, r.shortname, rn.name AS coursealias
FROM {role} r
LEFT JOIN {role_context_levels} rcl ON (rcl.roleid = r.id AND rcl.contextlevel = :contextlevel)
LEFT JOIN {role_names} rn ON (rn.contextid = :coursecontext AND rn.roleid = r.id)
WHERE rcl.id IS NOT NULL $addrole
ORDER BY sortorder DESC";
$roles = $DB->get_records_sql($sql, $params);
return role_fix_names($roles, $context, ROLENAME_BOTH, true);
}
/**
* Return context levels where this role is assignable.
*
* @param integer $roleid the id of a role.
* @return array list of the context levels at which this role may be assigned.
*/
function get_role_contextlevels($roleid) {
global $DB;
return $DB->get_records_menu('role_context_levels', array('roleid' => $roleid),
'contextlevel', 'id,contextlevel');
}
/**
* Return roles suitable for assignment at the specified context level.
*
* NOTE: this function name looks like a typo, should be probably get_roles_for_contextlevel()
*
* @param integer $contextlevel a contextlevel.
* @return array list of role ids that are assignable at this context level.
*/
function get_roles_for_contextlevels($contextlevel) {
global $DB;
return $DB->get_records_menu('role_context_levels', array('contextlevel' => $contextlevel),
'', 'id,roleid');
}
/**
* Returns default context levels where roles can be assigned.
*
* @param string $rolearchetype one of the role archetypes - that is, one of the keys
* from the array returned by get_role_archetypes();
* @return array list of the context levels at which this type of role may be assigned by default.
*/
function get_default_contextlevels($rolearchetype) {
static $defaults = array(
'manager' => array(CONTEXT_SYSTEM, CONTEXT_COURSECAT, CONTEXT_COURSE),
'coursecreator' => array(CONTEXT_SYSTEM, CONTEXT_COURSECAT),
'editingteacher' => array(CONTEXT_COURSE, CONTEXT_MODULE),
'teacher' => array(CONTEXT_COURSE, CONTEXT_MODULE),
'student' => array(CONTEXT_COURSE, CONTEXT_MODULE),
'guest' => array(),
'user' => array(),
'frontpage' => array());
if (isset($defaults[$rolearchetype])) {
return $defaults[$rolearchetype];
} else {
return array();
}
}
/**
* Set the context levels at which a particular role can be assigned.
* Throws exceptions in case of error.
*
* @param integer $roleid the id of a role.
* @param array $contextlevels the context levels at which this role should be assignable,
* duplicate levels are removed.
* @return void
*/
function set_role_contextlevels($roleid, array $contextlevels) {
global $DB;
$DB->delete_records('role_context_levels', array('roleid' => $roleid));
$rcl = new stdClass();
$rcl->roleid = $roleid;
$contextlevels = array_unique($contextlevels);
foreach ($contextlevels as $level) {
$rcl->contextlevel = $level;
$DB->insert_record('role_context_levels', $rcl, false, true);
}
}
/**
* Gets sql joins for finding users with capability in the given context.
*
* @param context $context Context for the join.
* @param string|array $capability Capability name or array of names.
* If an array is provided then this is the equivalent of a logical 'OR',
* i.e. the user needs to have one of these capabilities.
* @param string $useridcolumn e.g. 'u.id'.
* @return \core\dml\sql_join Contains joins, wheres, params.
* This function will set ->cannotmatchanyrows if applicable.
* This may let you skip doing a DB query.
*/
function get_with_capability_join(context $context, $capability, $useridcolumn) {
global $CFG, $DB;
// Add a unique prefix to param names to ensure they are unique.
static $i = 0;
$i++;
$paramprefix = 'eu' . $i . '_';
$defaultuserroleid = isset($CFG->defaultuserroleid) ? $CFG->defaultuserroleid : 0;
$defaultfrontpageroleid = isset($CFG->defaultfrontpageroleid) ? $CFG->defaultfrontpageroleid : 0;
$ctxids = trim($context->path, '/');
$ctxids = str_replace('/', ',', $ctxids);
// Context is the frontpage
$isfrontpage = $context->contextlevel == CONTEXT_COURSE && $context->instanceid == SITEID;
$isfrontpage = $isfrontpage || is_inside_frontpage($context);
$caps = (array) $capability;
// Construct list of context paths bottom --> top.
list($contextids, $paths) = get_context_info_list($context);
// We need to find out all roles that have these capabilities either in definition or in overrides.
$defs = [];
list($incontexts, $params) = $DB->get_in_or_equal($contextids, SQL_PARAMS_NAMED, $paramprefix . 'con');
list($incaps, $params2) = $DB->get_in_or_equal($caps, SQL_PARAMS_NAMED, $paramprefix . 'cap');
// Check whether context locking is enabled.
// Filter out any write capability if this is the case.
$excludelockedcaps = '';
$excludelockedcapsparams = [];
if (!empty($CFG->contextlocking) && $context->locked) {
$excludelockedcaps = 'AND (cap.captype = :capread OR cap.name = :managelockscap)';
$excludelockedcapsparams['capread'] = 'read';
$excludelockedcapsparams['managelockscap'] = 'moodle/site:managecontextlocks';
}
$params = array_merge($params, $params2, $excludelockedcapsparams);
$sql = "SELECT rc.id, rc.roleid, rc.permission, rc.capability, ctx.path
FROM {role_capabilities} rc
JOIN {capabilities} cap ON rc.capability = cap.name
JOIN {context} ctx on rc.contextid = ctx.id
WHERE rc.contextid $incontexts AND rc.capability $incaps $excludelockedcaps";
$rcs = $DB->get_records_sql($sql, $params);
foreach ($rcs as $rc) {
$defs[$rc->capability][$rc->path][$rc->roleid] = $rc->permission;
}
// Go through the permissions bottom-->top direction to evaluate the current permission,
// first one wins (prohibit is an exception that always wins).
$access = [];
foreach ($caps as $cap) {
foreach ($paths as $path) {
if (empty($defs[$cap][$path])) {
continue;
}
foreach ($defs[$cap][$path] as $roleid => $perm) {
if ($perm == CAP_PROHIBIT) {
$access[$cap][$roleid] = CAP_PROHIBIT;
continue;
}
if (!isset($access[$cap][$roleid])) {
$access[$cap][$roleid] = (int)$perm;
}
}
}
}
// Make lists of roles that are needed and prohibited in this context.
$needed = []; // One of these is enough.
$prohibited = []; // Must not have any of these.
foreach ($caps as $cap) {
if (empty($access[$cap])) {
continue;
}
foreach ($access[$cap] as $roleid => $perm) {
if ($perm == CAP_PROHIBIT) {
unset($needed[$cap][$roleid]);
$prohibited[$cap][$roleid] = true;
} else if ($perm == CAP_ALLOW and empty($prohibited[$cap][$roleid])) {
$needed[$cap][$roleid] = true;
}
}
if (empty($needed[$cap]) or !empty($prohibited[$cap][$defaultuserroleid])) {
// Easy, nobody has the permission.
unset($needed[$cap]);
unset($prohibited[$cap]);
} else if ($isfrontpage and !empty($prohibited[$cap][$defaultfrontpageroleid])) {
// Everybody is disqualified on the frontpage.
unset($needed[$cap]);
unset($prohibited[$cap]);
}
if (empty($prohibited[$cap])) {
unset($prohibited[$cap]);
}
}
if (empty($needed)) {
// There can not be anybody if no roles match this request.
return new \core\dml\sql_join('', '1 = 2', [], true);
}
if (empty($prohibited)) {
// We can compact the needed roles.
$n = [];
foreach ($needed as $cap) {
foreach ($cap as $roleid => $unused) {
$n[$roleid] = true;
}
}
$needed = ['any' => $n];
unset($n);
}
// Prepare query clauses.
$wherecond = [];
$params = [];
$joins = [];
$cannotmatchanyrows = false;
// We never return deleted users or guest account.
// Use a hack to get the deleted user column without an API change.
$deletedusercolumn = substr($useridcolumn, 0, -2) . 'deleted';
$wherecond[] = "$deletedusercolumn = 0 AND $useridcolumn <> :{$paramprefix}guestid";
$params[$paramprefix . 'guestid'] = $CFG->siteguest;
// Now add the needed and prohibited roles conditions as joins.
if (!empty($needed['any'])) {
// Simple case - there are no prohibits involved.
if (!empty($needed['any'][$defaultuserroleid]) ||
($isfrontpage && !empty($needed['any'][$defaultfrontpageroleid]))) {
// Everybody.
} else {
$joins[] = "JOIN (SELECT DISTINCT userid
FROM {role_assignments}
WHERE contextid IN ($ctxids)
AND roleid IN (" . implode(',', array_keys($needed['any'])) . ")
) ra ON ra.userid = $useridcolumn";
}
} else {
$unions = [];
$everybody = false;
foreach ($needed as $cap => $unused) {
if (empty($prohibited[$cap])) {
if (!empty($needed[$cap][$defaultuserroleid]) ||
($isfrontpage && !empty($needed[$cap][$defaultfrontpageroleid]))) {
$everybody = true;
break;
} else {
$unions[] = "SELECT userid
FROM {role_assignments}
WHERE contextid IN ($ctxids)
AND roleid IN (".implode(',', array_keys($needed[$cap])) .")";
}
} else {
if (!empty($prohibited[$cap][$defaultuserroleid]) ||
($isfrontpage && !empty($prohibited[$cap][$defaultfrontpageroleid]))) {
// Nobody can have this cap because it is prohibited in default roles.
continue;
} else if (!empty($needed[$cap][$defaultuserroleid]) ||
($isfrontpage && !empty($needed[$cap][$defaultfrontpageroleid]))) {
// Everybody except the prohibited - hiding does not matter.
$unions[] = "SELECT id AS userid
FROM {user}
WHERE id NOT IN (SELECT userid
FROM {role_assignments}
WHERE contextid IN ($ctxids)
AND roleid IN (" . implode(',', array_keys($prohibited[$cap])) . "))";
} else {
$unions[] = "SELECT userid
FROM {role_assignments}
WHERE contextid IN ($ctxids) AND roleid IN (" . implode(',', array_keys($needed[$cap])) . ")
AND userid NOT IN (
SELECT userid
FROM {role_assignments}
WHERE contextid IN ($ctxids)
AND roleid IN (" . implode(',', array_keys($prohibited[$cap])) . "))";
}
}
}
if (!$everybody) {
if ($unions) {
$joins[] = "JOIN (
SELECT DISTINCT userid
FROM (
" . implode("\n UNION \n", $unions) . "
) us
) ra ON ra.userid = $useridcolumn";
} else {
// Only prohibits found - nobody can be matched.
$wherecond[] = "1 = 2";
$cannotmatchanyrows = true;
}
}
}
return new \core\dml\sql_join(implode("\n", $joins), implode(" AND ", $wherecond), $params, $cannotmatchanyrows);
}
/**
* Who has this capability in this context?
*
* This can be a very expensive call - use sparingly and keep
* the results if you are going to need them again soon.
*
* Note if $fields is empty this function attempts to get u.*
* which can get rather large - and has a serious perf impact
* on some DBs.
*
* @param context $context
* @param string|array $capability - capability name(s)
* @param string $fields - fields to be pulled. The user table is aliased to 'u'. u.id MUST be included.
* @param string $sort - the sort order. Default is lastaccess time.
* @param mixed $limitfrom - number of records to skip (offset)
* @param mixed $limitnum - number of records to fetch
* @param string|array $groups - single group or array of groups - only return
* users who are in one of these group(s).
* @param string|array $exceptions - list of users to exclude, comma separated or array
* @param bool $notuseddoanything not used any more, admin accounts are never returned
* @param bool $notusedview - use get_enrolled_sql() instead
* @param bool $useviewallgroups if $groups is set the return users who
* have capability both $capability and moodle/site:accessallgroups
* in this context, as well as users who have $capability and who are
* in $groups.
* @return array of user records
*/
function get_users_by_capability(context $context, $capability, $fields = '', $sort = '', $limitfrom = '', $limitnum = '',
$groups = '', $exceptions = '', $notuseddoanything = null, $notusedview = null, $useviewallgroups = false) {
global $CFG, $DB;
// Context is a course page other than the frontpage.
$iscoursepage = $context->contextlevel == CONTEXT_COURSE && $context->instanceid != SITEID;
// Set up default fields list if necessary.
if (empty($fields)) {
if ($iscoursepage) {
$fields = 'u.*, ul.timeaccess AS lastaccess';
} else {
$fields = 'u.*';
}
} else {
if ($CFG->debugdeveloper && strpos($fields, 'u.*') === false && strpos($fields, 'u.id') === false) {
debugging('u.id must be included in the list of fields passed to get_users_by_capability().', DEBUG_DEVELOPER);
}
}
// Set up default sort if necessary.
if (empty($sort)) { // default to course lastaccess or just lastaccess
if ($iscoursepage) {
$sort = 'ul.timeaccess';
} else {
$sort = 'u.lastaccess';
}
}
// Get the bits of SQL relating to capabilities.
$sqljoin = get_with_capability_join($context, $capability, 'u.id');
if ($sqljoin->cannotmatchanyrows) {
return [];
}
// Prepare query clauses.
$wherecond = [$sqljoin->wheres];
$params = $sqljoin->params;
$joins = [$sqljoin->joins];
// Add user lastaccess JOIN, if required.
if ((strpos($sort, 'ul.timeaccess') === false) and (strpos($fields, 'ul.timeaccess') === false)) {
// Here user_lastaccess is not required MDL-13810.
} else {
if ($iscoursepage) {
$joins[] = "LEFT OUTER JOIN {user_lastaccess} ul ON (ul.userid = u.id AND ul.courseid = {$context->instanceid})";
} else {
throw new coding_exception('Invalid sort in get_users_by_capability(), ul.timeaccess allowed only for course contexts.');
}
}
// Groups.
if ($groups) {
$groups = (array)$groups;
list($grouptest, $grpparams) = $DB->get_in_or_equal($groups, SQL_PARAMS_NAMED, 'grp');
$joins[] = "LEFT OUTER JOIN (SELECT DISTINCT userid
FROM {groups_members}
WHERE groupid $grouptest
) gm ON gm.userid = u.id";
$params = array_merge($params, $grpparams);
$grouptest = 'gm.userid IS NOT NULL';
if ($useviewallgroups) {
$viewallgroupsusers = get_users_by_capability($context, 'moodle/site:accessallgroups', 'u.id, u.id', '', '', '', '', $exceptions);
if (!empty($viewallgroupsusers)) {
$grouptest .= ' OR u.id IN (' . implode(',', array_keys($viewallgroupsusers)) . ')';
}
}
$wherecond[] = "($grouptest)";
}
// User exceptions.
if (!empty($exceptions)) {
$exceptions = (array)$exceptions;
list($exsql, $exparams) = $DB->get_in_or_equal($exceptions, SQL_PARAMS_NAMED, 'exc', false);
$params = array_merge($params, $exparams);
$wherecond[] = "u.id $exsql";
}
// Collect WHERE conditions and needed joins.
$where = implode(' AND ', $wherecond);
if ($where !== '') {
$where = 'WHERE ' . $where;
}
$joins = implode("\n", $joins);
// Finally! we have all the bits, run the query.
$sql = "SELECT $fields
FROM {user} u
$joins
$where
ORDER BY $sort";
return $DB->get_records_sql($sql, $params, $limitfrom, $limitnum);
}
/**
* Re-sort a users array based on a sorting policy
*
* Will re-sort a $users results array (from get_users_by_capability(), usually)
* based on a sorting policy. This is to support the odd practice of
* sorting teachers by 'authority', where authority was "lowest id of the role
* assignment".
*
* Will execute 1 database query. Only suitable for small numbers of users, as it
* uses an u.id IN() clause.
*
* Notes about the sorting criteria.
*
* As a default, we cannot rely on role.sortorder because then
* admins/coursecreators will always win. That is why the sane
* rule "is locality matters most", with sortorder as 2nd
* consideration.
*
* If you want role.sortorder, use the 'sortorder' policy, and
* name explicitly what roles you want to cover. It's probably
* a good idea to see what roles have the capabilities you want
* (array_diff() them against roiles that have 'can-do-anything'
* to weed out admin-ish roles. Or fetch a list of roles from
* variables like $CFG->coursecontact .
*
* @param array $users Users array, keyed on userid
* @param context $context
* @param array $roles ids of the roles to include, optional
* @param string $sortpolicy defaults to locality, more about
* @return array sorted copy of the array
*/
function sort_by_roleassignment_authority($users, context $context, $roles = array(), $sortpolicy = 'locality') {
global $DB;
$userswhere = ' ra.userid IN (' . implode(',',array_keys($users)) . ')';
$contextwhere = 'AND ra.contextid IN ('.str_replace('/', ',',substr($context->path, 1)).')';
if (empty($roles)) {
$roleswhere = '';
} else {
$roleswhere = ' AND ra.roleid IN ('.implode(',',$roles).')';
}
$sql = "SELECT ra.userid
FROM {role_assignments} ra
JOIN {role} r
ON ra.roleid=r.id
JOIN {context} ctx
ON ra.contextid=ctx.id
WHERE $userswhere
$contextwhere
$roleswhere";
// Default 'locality' policy -- read PHPDoc notes
// about sort policies...
$orderby = 'ORDER BY '
.'ctx.depth DESC, ' /* locality wins */
.'r.sortorder ASC, ' /* rolesorting 2nd criteria */
.'ra.id'; /* role assignment order tie-breaker */
if ($sortpolicy === 'sortorder') {
$orderby = 'ORDER BY '
.'r.sortorder ASC, ' /* rolesorting 2nd criteria */
.'ra.id'; /* role assignment order tie-breaker */
}
$sortedids = $DB->get_fieldset_sql($sql . $orderby);
$sortedusers = array();
$seen = array();
foreach ($sortedids as $id) {
// Avoid duplicates
if (isset($seen[$id])) {
continue;
}
$seen[$id] = true;
// assign
$sortedusers[$id] = $users[$id];
}
return $sortedusers;
}
/**
* Gets all the users assigned this role in this context or higher
*
* Note that moodle is based on capabilities and it is usually better
* to check permissions than to check role ids as the capabilities
* system is more flexible. If you really need, you can to use this
* function but consider has_capability() as a possible substitute.
*
* All $sort fields are added into $fields if not present there yet.
*
* If $roleid is an array or is empty (all roles) you need to set $fields
* (and $sort by extension) params according to it, as the first field
* returned by the database should be unique (ra.id is the best candidate).
*
* @param int $roleid (can also be an array of ints!)
* @param context $context
* @param bool $parent if true, get list of users assigned in higher context too
* @param string $fields fields from user (u.) , role assignment (ra) or role (r.)
* @param string $sort sort from user (u.) , role assignment (ra.) or role (r.).
* null => use default sort from users_order_by_sql.
* @param bool $all true means all, false means limit to enrolled users
* @param string $group defaults to ''
* @param mixed $limitfrom defaults to ''
* @param mixed $limitnum defaults to ''
* @param string $extrawheretest defaults to ''
* @param array $whereorsortparams any paramter values used by $sort or $extrawheretest.
* @return array
*/
function get_role_users($roleid, context $context, $parent = false, $fields = '',
$sort = null, $all = true, $group = '',
$limitfrom = '', $limitnum = '', $extrawheretest = '', $whereorsortparams = array()) {
global $DB;
if (empty($fields)) {
$allnames = get_all_user_name_fields(true, 'u');
$fields = 'u.id, u.confirmed, u.username, '. $allnames . ', ' .
'u.maildisplay, u.mailformat, u.maildigest, u.email, u.emailstop, u.city, '.
'u.country, u.picture, u.idnumber, u.department, u.institution, '.
'u.lang, u.timezone, u.lastaccess, u.mnethostid, r.name AS rolename, r.sortorder, '.
'r.shortname AS roleshortname, rn.name AS rolecoursealias';
}
// Prevent wrong function uses.
if ((empty($roleid) || is_array($roleid)) && strpos($fields, 'ra.id') !== 0) {
debugging('get_role_users() without specifying one single roleid needs to be called prefixing ' .
'role assignments id (ra.id) as unique field, you can use $fields param for it.');
if (!empty($roleid)) {
// Solving partially the issue when specifying multiple roles.
$users = array();
foreach ($roleid as $id) {
// Ignoring duplicated keys keeping the first user appearance.
$users = $users + get_role_users($id, $context, $parent, $fields, $sort, $all, $group,
$limitfrom, $limitnum, $extrawheretest, $whereorsortparams);
}
return $users;
}
}
$parentcontexts = '';
if ($parent) {
$parentcontexts = substr($context->path, 1); // kill leading slash
$parentcontexts = str_replace('/', ',', $parentcontexts);
if ($parentcontexts !== '') {
$parentcontexts = ' OR ra.contextid IN ('.$parentcontexts.' )';
}
}
if ($roleid) {
list($rids, $params) = $DB->get_in_or_equal($roleid, SQL_PARAMS_NAMED, 'r');
$roleselect = "AND ra.roleid $rids";
} else {
$params = array();
$roleselect = '';
}
if ($coursecontext = $context->get_course_context(false)) {
$params['coursecontext'] = $coursecontext->id;
} else {
$params['coursecontext'] = 0;
}
if ($group) {
$groupjoin = "JOIN {groups_members} gm ON gm.userid = u.id";
$groupselect = " AND gm.groupid = :groupid ";
$params['groupid'] = $group;
} else {
$groupjoin = '';
$groupselect = '';
}
$params['contextid'] = $context->id;
if ($extrawheretest) {
$extrawheretest = ' AND ' . $extrawheretest;
}
if ($whereorsortparams) {
$params = array_merge($params, $whereorsortparams);
}
if (!$sort) {
list($sort, $sortparams) = users_order_by_sql('u');
$params = array_merge($params, $sortparams);
}
// Adding the fields from $sort that are not present in $fields.
$sortarray = preg_split('/,\s*/', $sort);
$fieldsarray = preg_split('/,\s*/', $fields);
// Discarding aliases from the fields.
$fieldnames = array();
foreach ($fieldsarray as $key => $field) {
list($fieldnames[$key]) = explode(' ', $field);
}
$addedfields = array();
foreach ($sortarray as $sortfield) {
// Throw away any additional arguments to the sort (e.g. ASC/DESC).
list($sortfield) = explode(' ', $sortfield);
list($tableprefix) = explode('.', $sortfield);
$fieldpresent = false;
foreach ($fieldnames as $fieldname) {
if ($fieldname === $sortfield || $fieldname === $tableprefix.'.*') {
$fieldpresent = true;
break;
}
}
if (!$fieldpresent) {
$fieldsarray[] = $sortfield;
$addedfields[] = $sortfield;
}
}
$fields = implode(', ', $fieldsarray);
if (!empty($addedfields)) {
$addedfields = implode(', ', $addedfields);
debugging('get_role_users() adding '.$addedfields.' to the query result because they were required by $sort but missing in $fields');
}
if ($all === null) {
// Previously null was used to indicate that parameter was not used.
$all = true;
}
if (!$all and $coursecontext) {
// Do not use get_enrolled_sql() here for performance reasons.
$ejoin = "JOIN {user_enrolments} ue ON ue.userid = u.id
JOIN {enrol} e ON (e.id = ue.enrolid AND e.courseid = :ecourseid)";
$params['ecourseid'] = $coursecontext->instanceid;
} else {
$ejoin = "";
}
$sql = "SELECT DISTINCT $fields, ra.roleid
FROM {role_assignments} ra
JOIN {user} u ON u.id = ra.userid
JOIN {role} r ON ra.roleid = r.id
$ejoin
LEFT JOIN {role_names} rn ON (rn.contextid = :coursecontext AND rn.roleid = r.id)
$groupjoin
WHERE (ra.contextid = :contextid $parentcontexts)
$roleselect
$groupselect
$extrawheretest
ORDER BY $sort"; // join now so that we can just use fullname() later
return $DB->get_records_sql($sql, $params, $limitfrom, $limitnum);
}
/**
* Counts all the users assigned this role in this context or higher
*
* @param int|array $roleid either int or an array of ints
* @param context $context
* @param bool $parent if true, get list of users assigned in higher context too
* @return int Returns the result count
*/
function count_role_users($roleid, context $context, $parent = false) {
global $DB;
if ($parent) {
if ($contexts = $context->get_parent_context_ids()) {
$parentcontexts = ' OR r.contextid IN ('.implode(',', $contexts).')';
} else {
$parentcontexts = '';
}
} else {
$parentcontexts = '';
}
if ($roleid) {
list($rids, $params) = $DB->get_in_or_equal($roleid, SQL_PARAMS_QM);
$roleselect = "AND r.roleid $rids";
} else {
$params = array();
$roleselect = '';
}
array_unshift($params, $context->id);
$sql = "SELECT COUNT(DISTINCT u.id)
FROM {role_assignments} r
JOIN {user} u ON u.id = r.userid
WHERE (r.contextid = ? $parentcontexts)
$roleselect
AND u.deleted = 0";
return $DB->count_records_sql($sql, $params);
}
/**
* This function gets the list of courses that this user has a particular capability in.
*
* It is now reasonably efficient, but bear in mind that if there are users who have the capability
* everywhere, it may return an array of all courses.
*
* @param string $capability Capability in question
* @param int $userid User ID or null for current user
* @param bool $doanything True if 'doanything' is permitted (default)
* @param string $fieldsexceptid Leave blank if you only need 'id' in the course records;
* otherwise use a comma-separated list of the fields you require, not including id.
* Add ctxid, ctxpath, ctxdepth etc to return course context information for preloading.
* @param string $orderby If set, use a comma-separated list of fields from course
* table with sql modifiers (DESC) if needed
* @param int $limit Limit the number of courses to return on success. Zero equals all entries.
* @return array|bool Array of courses, if none found false is returned.
*/
function get_user_capability_course($capability, $userid = null, $doanything = true, $fieldsexceptid = '', $orderby = '',
$limit = 0) {
global $DB, $USER;
// Default to current user.
if (!$userid) {
$userid = $USER->id;
}
if ($doanything && is_siteadmin($userid)) {
// If the user is a site admin and $doanything is enabled then there is no need to restrict
// the list of courses.
$contextlimitsql = '';
$contextlimitparams = [];
} else {
// Gets SQL to limit contexts ('x' table) to those where the user has this capability.
list ($contextlimitsql, $contextlimitparams) = \core\access\get_user_capability_course_helper::get_sql(
$userid, $capability);
if (!$contextlimitsql) {
// If the does not have this capability in any context, return false without querying.
return false;
}
$contextlimitsql = 'WHERE' . $contextlimitsql;
}
// Convert fields list and ordering
$fieldlist = '';
if ($fieldsexceptid) {
$fields = array_map('trim', explode(',', $fieldsexceptid));
foreach ($fields as $field) {
// Context fields have a different alias.
if (strpos($field, 'ctx') === 0) {
switch($field) {
case 'ctxlevel' :
$realfield = 'contextlevel';
break;
case 'ctxinstance' :
$realfield = 'instanceid';
break;
default:
$realfield = substr($field, 3);
break;
}
$fieldlist .= ',x.' . $realfield . ' AS ' . $field;
} else {
$fieldlist .= ',c.'.$field;
}
}
}
if ($orderby) {
$fields = explode(',', $orderby);
$orderby = '';
foreach ($fields as $field) {
if ($orderby) {
$orderby .= ',';
}
$orderby .= 'c.'.$field;
}
$orderby = 'ORDER BY '.$orderby;
}
$courses = array();
$rs = $DB->get_recordset_sql("
SELECT c.id $fieldlist
FROM {course} c
JOIN {context} x ON c.id = x.instanceid AND x.contextlevel = ?
$contextlimitsql
$orderby", array_merge([CONTEXT_COURSE], $contextlimitparams));
foreach ($rs as $course) {
$courses[] = $course;
$limit--;
if ($limit == 0) {
break;
}
}
$rs->close();
return empty($courses) ? false : $courses;
}
/**
* Switches the current user to another role for the current session and only
* in the given context.
*
* The caller *must* check
* - that this op is allowed
* - that the requested role can be switched to in this context (use get_switchable_roles)
* - that the requested role is NOT $CFG->defaultuserroleid
*
* To "unswitch" pass 0 as the roleid.
*
* This function *will* modify $USER->access - beware
*
* @param integer $roleid the role to switch to.
* @param context $context the context in which to perform the switch.
* @return bool success or failure.
*/
function role_switch($roleid, context $context) {
global $USER;
// Add the ghost RA to $USER->access as $USER->access['rsw'][$path] = $roleid.
// To un-switch just unset($USER->access['rsw'][$path]).
//
// Note: it is not possible to switch to roles that do not have course:view
if (!isset($USER->access)) {
load_all_capabilities();
}
// Add the switch RA
if ($roleid == 0) {
unset($USER->access['rsw'][$context->path]);
return true;
}
$USER->access['rsw'][$context->path] = $roleid;
return true;
}
/**
* Checks if the user has switched roles within the given course.
*
* Note: You can only switch roles within the course, hence it takes a course id
* rather than a context. On that note Petr volunteered to implement this across
* all other contexts, all requests for this should be forwarded to him ;)
*
* @param int $courseid The id of the course to check
* @return bool True if the user has switched roles within the course.
*/
function is_role_switched($courseid) {
global $USER;
$context = context_course::instance($courseid, MUST_EXIST);
return (!empty($USER->access['rsw'][$context->path]));
}
/**
* Get any role that has an override on exact context
*
* @param context $context The context to check
* @return array An array of roles
*/
function get_roles_with_override_on_context(context $context) {
global $DB;
return $DB->get_records_sql("SELECT r.*
FROM {role_capabilities} rc, {role} r
WHERE rc.roleid = r.id AND rc.contextid = ?",
array($context->id));
}
/**
* Get all capabilities for this role on this context (overrides)
*
* @param stdClass $role
* @param context $context
* @return array
*/
function get_capabilities_from_role_on_context($role, context $context) {
global $DB;
return $DB->get_records_sql("SELECT *
FROM {role_capabilities}
WHERE contextid = ? AND roleid = ?",
array($context->id, $role->id));
}
/**
* Find all user assignment of users for this role, on this context
*
* @param stdClass $role
* @param context $context
* @return array
*/
function get_users_from_role_on_context($role, context $context) {
global $DB;
return $DB->get_records_sql("SELECT *
FROM {role_assignments}
WHERE contextid = ? AND roleid = ?",
array($context->id, $role->id));
}
/**
* Simple function returning a boolean true if user has roles
* in context or parent contexts, otherwise false.
*
* @param int $userid
* @param int $roleid
* @param int $contextid empty means any context
* @return bool
*/
function user_has_role_assignment($userid, $roleid, $contextid = 0) {
global $DB;
if ($contextid) {
if (!$context = context::instance_by_id($contextid, IGNORE_MISSING)) {
return false;
}
$parents = $context->get_parent_context_ids(true);
list($contexts, $params) = $DB->get_in_or_equal($parents, SQL_PARAMS_NAMED, 'r');
$params['userid'] = $userid;
$params['roleid'] = $roleid;
$sql = "SELECT COUNT(ra.id)
FROM {role_assignments} ra
WHERE ra.userid = :userid AND ra.roleid = :roleid AND ra.contextid $contexts";
$count = $DB->get_field_sql($sql, $params);
return ($count > 0);
} else {
return $DB->record_exists('role_assignments', array('userid'=>$userid, 'roleid'=>$roleid));
}
}
/**
* Get localised role name or alias if exists and format the text.
*
* @param stdClass $role role object
* - optional 'coursealias' property should be included for performance reasons if course context used
* - description property is not required here
* @param context|bool $context empty means system context
* @param int $rolenamedisplay type of role name
* @return string localised role name or course role name alias
*/
function role_get_name(stdClass $role, $context = null, $rolenamedisplay = ROLENAME_ALIAS) {
global $DB;
if ($rolenamedisplay == ROLENAME_SHORT) {
return $role->shortname;
}
if (!$context or !$coursecontext = $context->get_course_context(false)) {
$coursecontext = null;
}
if ($coursecontext and !property_exists($role, 'coursealias') and ($rolenamedisplay == ROLENAME_ALIAS or $rolenamedisplay == ROLENAME_BOTH or $rolenamedisplay == ROLENAME_ALIAS_RAW)) {
$role = clone($role); // Do not modify parameters.
if ($r = $DB->get_record('role_names', array('roleid'=>$role->id, 'contextid'=>$coursecontext->id))) {
$role->coursealias = $r->name;
} else {
$role->coursealias = null;
}
}
if ($rolenamedisplay == ROLENAME_ALIAS_RAW) {
if ($coursecontext) {
return $role->coursealias;
} else {
return null;
}
}
if (trim($role->name) !== '') {
// For filtering always use context where was the thing defined - system for roles here.
$original = format_string($role->name, true, array('context'=>context_system::instance()));
} else {
// Empty role->name means we want to see localised role name based on shortname,
// only default roles are supposed to be localised.
switch ($role->shortname) {
case 'manager': $original = get_string('manager', 'role'); break;
case 'coursecreator': $original = get_string('coursecreators'); break;
case 'editingteacher': $original = get_string('defaultcourseteacher'); break;
case 'teacher': $original = get_string('noneditingteacher'); break;
case 'student': $original = get_string('defaultcoursestudent'); break;
case 'guest': $original = get_string('guest'); break;
case 'user': $original = get_string('authenticateduser'); break;
case 'frontpage': $original = get_string('frontpageuser', 'role'); break;
// We should not get here, the role UI should require the name for custom roles!
default: $original = $role->shortname; break;
}
}
if ($rolenamedisplay == ROLENAME_ORIGINAL) {
return $original;
}
if ($rolenamedisplay == ROLENAME_ORIGINALANDSHORT) {
return "$original ($role->shortname)";
}
if ($rolenamedisplay == ROLENAME_ALIAS) {
if ($coursecontext and trim($role->coursealias) !== '') {
return format_string($role->coursealias, true, array('context'=>$coursecontext));
} else {
return $original;
}
}
if ($rolenamedisplay == ROLENAME_BOTH) {
if ($coursecontext and trim($role->coursealias) !== '') {
return format_string($role->coursealias, true, array('context'=>$coursecontext)) . " ($original)";
} else {
return $original;
}
}
throw new coding_exception('Invalid $rolenamedisplay parameter specified in role_get_name()');
}
/**
* Returns localised role description if available.
* If the name is empty it tries to find the default role name using
* hardcoded list of default role names or other methods in the future.
*
* @param stdClass $role
* @return string localised role name
*/
function role_get_description(stdClass $role) {
if (!html_is_blank($role->description)) {
return format_text($role->description, FORMAT_HTML, array('context'=>context_system::instance()));
}
switch ($role->shortname) {
case 'manager': return get_string('managerdescription', 'role');
case 'coursecreator': return get_string('coursecreatorsdescription');
case 'editingteacher': return get_string('defaultcourseteacherdescription');
case 'teacher': return get_string('noneditingteacherdescription');
case 'student': return get_string('defaultcoursestudentdescription');
case 'guest': return get_string('guestdescription');
case 'user': return get_string('authenticateduserdescription');
case 'frontpage': return get_string('frontpageuserdescription', 'role');
default: return '';
}
}
/**
* Get all the localised role names for a context.
*
* In new installs default roles have empty names, this function
* add localised role names using current language pack.
*
* @param context $context the context, null means system context
* @param array of role objects with a ->localname field containing the context-specific role name.
* @param int $rolenamedisplay
* @param bool $returnmenu true means id=>localname, false means id=>rolerecord
* @return array Array of context-specific role names, or role objects with a ->localname field added.
*/
function role_get_names(context $context = null, $rolenamedisplay = ROLENAME_ALIAS, $returnmenu = null) {
return role_fix_names(get_all_roles($context), $context, $rolenamedisplay, $returnmenu);
}
/**
* Prepare list of roles for display, apply aliases and localise default role names.
*
* @param array $roleoptions array roleid => roleobject (with optional coursealias), strings are accepted for backwards compatibility only
* @param context $context the context, null means system context
* @param int $rolenamedisplay
* @param bool $returnmenu null means keep the same format as $roleoptions, true means id=>localname, false means id=>rolerecord
* @return array Array of context-specific role names, or role objects with a ->localname field added.
*/
function role_fix_names($roleoptions, context $context = null, $rolenamedisplay = ROLENAME_ALIAS, $returnmenu = null) {
global $DB;
if (empty($roleoptions)) {
return array();
}
if (!$context or !$coursecontext = $context->get_course_context(false)) {
$coursecontext = null;
}
// We usually need all role columns...
$first = reset($roleoptions);
if ($returnmenu === null) {
$returnmenu = !is_object($first);
}
if (!is_object($first) or !property_exists($first, 'shortname')) {
$allroles = get_all_roles($context);
foreach ($roleoptions as $rid => $unused) {
$roleoptions[$rid] = $allroles[$rid];
}
}
// Inject coursealias if necessary.
if ($coursecontext and ($rolenamedisplay == ROLENAME_ALIAS_RAW or $rolenamedisplay == ROLENAME_ALIAS or $rolenamedisplay == ROLENAME_BOTH)) {
$first = reset($roleoptions);
if (!property_exists($first, 'coursealias')) {
$aliasnames = $DB->get_records('role_names', array('contextid'=>$coursecontext->id));
foreach ($aliasnames as $alias) {
if (isset($roleoptions[$alias->roleid])) {
$roleoptions[$alias->roleid]->coursealias = $alias->name;
}
}
}
}
// Add localname property.
foreach ($roleoptions as $rid => $role) {
$roleoptions[$rid]->localname = role_get_name($role, $coursecontext, $rolenamedisplay);
}
if (!$returnmenu) {
return $roleoptions;
}
$menu = array();
foreach ($roleoptions as $rid => $role) {
$menu[$rid] = $role->localname;
}
return $menu;
}
/**
* Aids in detecting if a new line is required when reading a new capability
*
* This function helps admin/roles/manage.php etc to detect if a new line should be printed
* when we read in a new capability.
* Most of the time, if the 2 components are different we should print a new line, (e.g. course system->rss client)
* but when we are in grade, all reports/import/export capabilities should be together
*
* @param string $cap component string a
* @param string $comp component string b
* @param int $contextlevel
* @return bool whether 2 component are in different "sections"
*/
function component_level_changed($cap, $comp, $contextlevel) {
if (strstr($cap->component, '/') && strstr($comp, '/')) {
$compsa = explode('/', $cap->component);
$compsb = explode('/', $comp);
// list of system reports
if (($compsa[0] == 'report') && ($compsb[0] == 'report')) {
return false;
}
// we are in gradebook, still
if (($compsa[0] == 'gradeexport' || $compsa[0] == 'gradeimport' || $compsa[0] == 'gradereport') &&
($compsb[0] == 'gradeexport' || $compsb[0] == 'gradeimport' || $compsb[0] == 'gradereport')) {
return false;
}
if (($compsa[0] == 'coursereport') && ($compsb[0] == 'coursereport')) {
return false;
}
}
return ($cap->component != $comp || $cap->contextlevel != $contextlevel);
}
/**
* Fix the roles.sortorder field in the database, so it contains sequential integers,
* and return an array of roleids in order.
*
* @param array $allroles array of roles, as returned by get_all_roles();
* @return array $role->sortorder =-> $role->id with the keys in ascending order.
*/
function fix_role_sortorder($allroles) {
global $DB;
$rolesort = array();
$i = 0;
foreach ($allroles as $role) {
$rolesort[$i] = $role->id;
if ($role->sortorder != $i) {
$r = new stdClass();
$r->id = $role->id;
$r->sortorder = $i;
$DB->update_record('role', $r);
$allroles[$role->id]->sortorder = $i;
}
$i++;
}
return $rolesort;
}
/**
* Switch the sort order of two roles (used in admin/roles/manage.php).
*
* @param stdClass $first The first role. Actually, only ->sortorder is used.
* @param stdClass $second The second role. Actually, only ->sortorder is used.
* @return boolean success or failure
*/
function switch_roles($first, $second) {
global $DB;
$temp = $DB->get_field('role', 'MAX(sortorder) + 1', array());
$result = $DB->set_field('role', 'sortorder', $temp, array('sortorder' => $first->sortorder));
$result = $result && $DB->set_field('role', 'sortorder', $first->sortorder, array('sortorder' => $second->sortorder));
$result = $result && $DB->set_field('role', 'sortorder', $second->sortorder, array('sortorder' => $temp));
return $result;
}
/**
* Duplicates all the base definitions of a role
*
* @param stdClass $sourcerole role to copy from
* @param int $targetrole id of role to copy to
*/
function role_cap_duplicate($sourcerole, $targetrole) {
global $DB;
$systemcontext = context_system::instance();
$caps = $DB->get_records_sql("SELECT *
FROM {role_capabilities}
WHERE roleid = ? AND contextid = ?",
array($sourcerole->id, $systemcontext->id));
// adding capabilities
foreach ($caps as $cap) {
unset($cap->id);
$cap->roleid = $targetrole;
$DB->insert_record('role_capabilities', $cap);
}
// Reset any cache of this role, including MUC.
accesslib_clear_role_cache($targetrole);
}
/**
* Returns two lists, this can be used to find out if user has capability.
* Having any needed role and no forbidden role in this context means
* user has this capability in this context.
* Use get_role_names_with_cap_in_context() if you need role names to display in the UI
*
* @param stdClass $context
* @param string $capability
* @return array($neededroles, $forbiddenroles)
*/
function get_roles_with_cap_in_context($context, $capability) {
global $DB;
$ctxids = trim($context->path, '/'); // kill leading slash
$ctxids = str_replace('/', ',', $ctxids);
$sql = "SELECT rc.id, rc.roleid, rc.permission, ctx.depth
FROM {role_capabilities} rc
JOIN {context} ctx ON ctx.id = rc.contextid
JOIN {capabilities} cap ON rc.capability = cap.name
WHERE rc.capability = :cap AND ctx.id IN ($ctxids)
ORDER BY rc.roleid ASC, ctx.depth DESC";
$params = array('cap'=>$capability);
if (!$capdefs = $DB->get_records_sql($sql, $params)) {
// no cap definitions --> no capability
return array(array(), array());
}
$forbidden = array();
$needed = array();
foreach ($capdefs as $def) {
if (isset($forbidden[$def->roleid])) {
continue;
}
if ($def->permission == CAP_PROHIBIT) {
$forbidden[$def->roleid] = $def->roleid;
unset($needed[$def->roleid]);
continue;
}
if (!isset($needed[$def->roleid])) {
if ($def->permission == CAP_ALLOW) {
$needed[$def->roleid] = true;
} else if ($def->permission == CAP_PREVENT) {
$needed[$def->roleid] = false;
}
}
}
unset($capdefs);
// remove all those roles not allowing
foreach ($needed as $key=>$value) {
if (!$value) {
unset($needed[$key]);
} else {
$needed[$key] = $key;
}
}
return array($needed, $forbidden);
}
/**
* Returns an array of role IDs that have ALL of the the supplied capabilities
* Uses get_roles_with_cap_in_context(). Returns $allowed minus $forbidden
*
* @param stdClass $context
* @param array $capabilities An array of capabilities
* @return array of roles with all of the required capabilities
*/
function get_roles_with_caps_in_context($context, $capabilities) {
$neededarr = array();
$forbiddenarr = array();
foreach ($capabilities as $caprequired) {
list($neededarr[], $forbiddenarr[]) = get_roles_with_cap_in_context($context, $caprequired);
}
$rolesthatcanrate = array();
if (!empty($neededarr)) {
foreach ($neededarr as $needed) {
if (empty($rolesthatcanrate)) {
$rolesthatcanrate = $needed;
} else {
//only want roles that have all caps
$rolesthatcanrate = array_intersect_key($rolesthatcanrate,$needed);
}
}
}
if (!empty($forbiddenarr) && !empty($rolesthatcanrate)) {
foreach ($forbiddenarr as $forbidden) {
//remove any roles that are forbidden any of the caps
$rolesthatcanrate = array_diff($rolesthatcanrate, $forbidden);
}
}
return $rolesthatcanrate;
}
/**
* Returns an array of role names that have ALL of the the supplied capabilities
* Uses get_roles_with_caps_in_context(). Returns $allowed minus $forbidden
*
* @param stdClass $context
* @param array $capabilities An array of capabilities
* @return array of roles with all of the required capabilities
*/
function get_role_names_with_caps_in_context($context, $capabilities) {
global $DB;
$rolesthatcanrate = get_roles_with_caps_in_context($context, $capabilities);
$allroles = $DB->get_records('role', null, 'sortorder DESC');
$roles = array();
foreach ($rolesthatcanrate as $r) {
$roles[$r] = $allroles[$r];
}
return role_fix_names($roles, $context, ROLENAME_ALIAS, true);
}
/**
* This function verifies the prohibit comes from this context
* and there are no more prohibits in parent contexts.
*
* @param int $roleid
* @param context $context
* @param string $capability name
* @return bool
*/
function prohibit_is_removable($roleid, context $context, $capability) {
global $DB;
$ctxids = trim($context->path, '/'); // kill leading slash
$ctxids = str_replace('/', ',', $ctxids);
$params = array('roleid'=>$roleid, 'cap'=>$capability, 'prohibit'=>CAP_PROHIBIT);
$sql = "SELECT ctx.id
FROM {role_capabilities} rc
JOIN {context} ctx ON ctx.id = rc.contextid
JOIN {capabilities} cap ON rc.capability = cap.name
WHERE rc.roleid = :roleid AND rc.permission = :prohibit AND rc.capability = :cap AND ctx.id IN ($ctxids)
ORDER BY ctx.depth DESC";
if (!$prohibits = $DB->get_records_sql($sql, $params)) {
// no prohibits == nothing to remove
return true;
}
if (count($prohibits) > 1) {
// more prohibits can not be removed
return false;
}
return !empty($prohibits[$context->id]);
}
/**
* More user friendly role permission changing,
* it should produce as few overrides as possible.
*
* @param int $roleid
* @param stdClass $context
* @param string $capname capability name
* @param int $permission
* @return void
*/
function role_change_permission($roleid, $context, $capname, $permission) {
global $DB;
if ($permission == CAP_INHERIT) {
unassign_capability($capname, $roleid, $context->id);
return;
}
$ctxids = trim($context->path, '/'); // kill leading slash
$ctxids = str_replace('/', ',', $ctxids);
$params = array('roleid'=>$roleid, 'cap'=>$capname);
$sql = "SELECT ctx.id, rc.permission, ctx.depth
FROM {role_capabilities} rc
JOIN {context} ctx ON ctx.id = rc.contextid
JOIN {capabilities} cap ON rc.capability = cap.name
WHERE rc.roleid = :roleid AND rc.capability = :cap AND ctx.id IN ($ctxids)
ORDER BY ctx.depth DESC";
if ($existing = $DB->get_records_sql($sql, $params)) {
foreach ($existing as $e) {
if ($e->permission == CAP_PROHIBIT) {
// prohibit can not be overridden, no point in changing anything
return;
}
}
$lowest = array_shift($existing);
if ($lowest->permission == $permission) {
// permission already set in this context or parent - nothing to do
return;
}
if ($existing) {
$parent = array_shift($existing);
if ($parent->permission == $permission) {
// permission already set in parent context or parent - just unset in this context
// we do this because we want as few overrides as possible for performance reasons
unassign_capability($capname, $roleid, $context->id);
return;
}
}
} else {
if ($permission == CAP_PREVENT) {
// nothing means role does not have permission
return;
}
}
// assign the needed capability
assign_capability($capname, $permission, $roleid, $context->id, true);
}
/**
* Basic moodle context abstraction class.
*
* Google confirms that no other important framework is using "context" class,
* we could use something else like mcontext or moodle_context, but we need to type
* this very often which would be annoying and it would take too much space...
*
* This class is derived from stdClass for backwards compatibility with
* odl $context record that was returned from DML $DB->get_record()
*
* @package core_access
* @category access
* @copyright Petr Skoda {@link http://skodak.org}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
* @since Moodle 2.2
*
* @property-read int $id context id
* @property-read int $contextlevel CONTEXT_SYSTEM, CONTEXT_COURSE, etc.
* @property-read int $instanceid id of related instance in each context
* @property-read string $path path to context, starts with system context
* @property-read int $depth
*/
abstract class context extends stdClass implements IteratorAggregate {
/**
* The context id
* Can be accessed publicly through $context->id
* @var int
*/
protected $_id;
/**
* The context level
* Can be accessed publicly through $context->contextlevel
* @var int One of CONTEXT_* e.g. CONTEXT_COURSE, CONTEXT_MODULE
*/
protected $_contextlevel;
/**
* Id of the item this context is related to e.g. COURSE_CONTEXT => course.id
* Can be accessed publicly through $context->instanceid
* @var int
*/
protected $_instanceid;
/**
* The path to the context always starting from the system context
* Can be accessed publicly through $context->path
* @var string
*/
protected $_path;
/**
* The depth of the context in relation to parent contexts
* Can be accessed publicly through $context->depth
* @var int
*/
protected $_depth;
/**
* Whether this context is locked or not.
*
* Can be accessed publicly through $context->locked.
*
* @var int
*/
protected $_locked;
/**
* @var array Context caching info
*/
private static $cache_contextsbyid = array();
/**
* @var array Context caching info
*/
private static $cache_contexts = array();
/**
* Context count
* Why do we do count contexts? Because count($array) is horribly slow for large arrays
* @var int
*/
protected static $cache_count = 0;
/**
* @var array Context caching info
*/
protected static $cache_preloaded = array();
/**
* @var context_system The system context once initialised
*/
protected static $systemcontext = null;
/**
* Resets the cache to remove all data.
* @static
*/
protected static function reset_caches() {
self::$cache_contextsbyid = array();
self::$cache_contexts = array();
self::$cache_count = 0;
self::$cache_preloaded = array();
self::$systemcontext = null;
}
/**
* Adds a context to the cache. If the cache is full, discards a batch of
* older entries.
*
* @static
* @param context $context New context to add
* @return void
*/
protected static function cache_add(context $context) {
if (isset(self::$cache_contextsbyid[$context->id])) {
// already cached, no need to do anything - this is relatively cheap, we do all this because count() is slow
return;
}
if (self::$cache_count >= CONTEXT_CACHE_MAX_SIZE) {
$i = 0;
foreach (self::$cache_contextsbyid as $ctx) {
$i++;
if ($i <= 100) {
// we want to keep the first contexts to be loaded on this page, hopefully they will be needed again later
continue;
}
if ($i > (CONTEXT_CACHE_MAX_SIZE / 3)) {
// we remove oldest third of the contexts to make room for more contexts
break;
}
unset(self::$cache_contextsbyid[$ctx->id]);
unset(self::$cache_contexts[$ctx->contextlevel][$ctx->instanceid]);
self::$cache_count--;
}
}
self::$cache_contexts[$context->contextlevel][$context->instanceid] = $context;
self::$cache_contextsbyid[$context->id] = $context;
self::$cache_count++;
}
/**
* Removes a context from the cache.
*
* @static
* @param context $context Context object to remove
* @return void
*/
protected static function cache_remove(context $context) {
if (!isset(self::$cache_contextsbyid[$context->id])) {
// not cached, no need to do anything - this is relatively cheap, we do all this because count() is slow
return;
}
unset(self::$cache_contexts[$context->contextlevel][$context->instanceid]);
unset(self::$cache_contextsbyid[$context->id]);
self::$cache_count--;
if (self::$cache_count < 0) {
self::$cache_count = 0;
}
}
/**
* Gets a context from the cache.
*
* @static
* @param int $contextlevel Context level
* @param int $instance Instance ID
* @return context|bool Context or false if not in cache
*/
protected static function cache_get($contextlevel, $instance) {
if (isset(self::$cache_contexts[$contextlevel][$instance])) {
return self::$cache_contexts[$contextlevel][$instance];
}
return false;
}
/**
* Gets a context from the cache based on its id.
*
* @static
* @param int $id Context ID
* @return context|bool Context or false if not in cache
*/
protected static function cache_get_by_id($id) {
if (isset(self::$cache_contextsbyid[$id])) {
return self::$cache_contextsbyid[$id];
}
return false;
}
/**
* Preloads context information from db record and strips the cached info.
*
* @static
* @param stdClass $rec
* @return void (modifies $rec)
*/
protected static function preload_from_record(stdClass $rec) {
$notenoughdata = false;
$notenoughdata = $notenoughdata || empty($rec->ctxid);
$notenoughdata = $notenoughdata || empty($rec->ctxlevel);
$notenoughdata = $notenoughdata || !isset($rec->ctxinstance);
$notenoughdata = $notenoughdata || empty($rec->ctxpath);
$notenoughdata = $notenoughdata || empty($rec->ctxdepth);
$notenoughdata = $notenoughdata || !isset($rec->ctxlocked);
if ($notenoughdata) {
// The record does not have enough data, passed here repeatedly or context does not exist yet.
if (isset($rec->ctxid) && !isset($rec->ctxlocked)) {
debugging('Locked value missing. Code is possibly not usings the getter properly.', DEBUG_DEVELOPER);
}
return;
}
$record = (object) [
'id' => $rec->ctxid,
'contextlevel' => $rec->ctxlevel,
'instanceid' => $rec->ctxinstance,
'path' => $rec->ctxpath,
'depth' => $rec->ctxdepth,
'locked' => $rec->ctxlocked,
];
unset($rec->ctxid);
unset($rec->ctxlevel);
unset($rec->ctxinstance);
unset($rec->ctxpath);
unset($rec->ctxdepth);
unset($rec->ctxlocked);
return context::create_instance_from_record($record);
}
// ====== magic methods =======
/**
* Magic setter method, we do not want anybody to modify properties from the outside
* @param string $name
* @param mixed $value
*/
public function __set($name, $value) {
debugging('Can not change context instance properties!');
}
/**
* Magic method getter, redirects to read only values.
* @param string $name
* @return mixed
*/
public function __get($name) {
switch ($name) {
case 'id':
return $this->_id;
case 'contextlevel':
return $this->_contextlevel;
case 'instanceid':
return $this->_instanceid;
case 'path':
return $this->_path;
case 'depth':
return $this->_depth;
case 'locked':
return $this->is_locked();
default:
debugging('Invalid context property accessed! '.$name);
return null;
}
}
/**
* Full support for isset on our magic read only properties.
* @param string $name
* @return bool
*/
public function __isset($name) {
switch ($name) {
case 'id':
return isset($this->_id);
case 'contextlevel':
return isset($this->_contextlevel);
case 'instanceid':
return isset($this->_instanceid);
case 'path':
return isset($this->_path);
case 'depth':
return isset($this->_depth);
case 'locked':
// Locked is always set.
return true;
default:
return false;
}
}
/**
* All properties are read only, sorry.
* @param string $name
*/
public function __unset($name) {
debugging('Can not unset context instance properties!');
}
// ====== implementing method from interface IteratorAggregate ======
/**
* Create an iterator because magic vars can't be seen by 'foreach'.
*
* Now we can convert context object to array using convert_to_array(),
* and feed it properly to json_encode().
*/
public function getIterator() {
$ret = array(
'id' => $this->id,
'contextlevel' => $this->contextlevel,
'instanceid' => $this->instanceid,
'path' => $this->path,
'depth' => $this->depth,
'locked' => $this->locked,
);
return new ArrayIterator($ret);
}
// ====== general context methods ======
/**
* Constructor is protected so that devs are forced to
* use context_xxx::instance() or context::instance_by_id().
*
* @param stdClass $record
*/
protected function __construct(stdClass $record) {
$this->_id = (int)$record->id;
$this->_contextlevel = (int)$record->contextlevel;
$this->_instanceid = $record->instanceid;
$this->_path = $record->path;
$this->_depth = $record->depth;
if (isset($record->locked)) {
$this->_locked = $record->locked;
} else if (!during_initial_install() && !moodle_needs_upgrading()) {
debugging('Locked value missing. Code is possibly not usings the getter properly.', DEBUG_DEVELOPER);
}
}
/**
* This function is also used to work around 'protected' keyword problems in context_helper.
* @static
* @param stdClass $record
* @return context instance
*/
protected static function create_instance_from_record(stdClass $record) {
$classname = context_helper::get_class_for_level($record->contextlevel);
if ($context = context::cache_get_by_id($record->id)) {
return $context;
}
$context = new $classname($record);
context::cache_add($context);
return $context;
}
/**
* Copy prepared new contexts from temp table to context table,
* we do this in db specific way for perf reasons only.
* @static
*/
protected static function merge_context_temp_table() {
global $DB;
/* MDL-11347:
* - mysql does not allow to use FROM in UPDATE statements
* - using two tables after UPDATE works in mysql, but might give unexpected
* results in pg 8 (depends on configuration)
* - using table alias in UPDATE does not work in pg < 8.2
*
* Different code for each database - mostly for performance reasons
*/
$dbfamily = $DB->get_dbfamily();
if ($dbfamily == 'mysql') {
$updatesql = "UPDATE {context} ct, {context_temp} temp
SET ct.path = temp.path,
ct.depth = temp.depth,
ct.locked = temp.locked
WHERE ct.id = temp.id";
} else if ($dbfamily == 'oracle') {
$updatesql = "UPDATE {context} ct
SET (ct.path, ct.depth, ct.locked) =
(SELECT temp.path, temp.depth, temp.locked
FROM {context_temp} temp
WHERE temp.id=ct.id)
WHERE EXISTS (SELECT 'x'
FROM {context_temp} temp
WHERE temp.id = ct.id)";
} else if ($dbfamily == 'postgres' or $dbfamily == 'mssql') {
$updatesql = "UPDATE {context}
SET path = temp.path,
depth = temp.depth,
locked = temp.locked
FROM {context_temp} temp
WHERE temp.id={context}.id";
} else {
// sqlite and others
$updatesql = "UPDATE {context}
SET path = (SELECT path FROM {context_temp} WHERE id = {context}.id),
depth = (SELECT depth FROM {context_temp} WHERE id = {context}.id),
locked = (SELECT locked FROM {context_temp} WHERE id = {context}.id)
WHERE id IN (SELECT id FROM {context_temp})";
}
$DB->execute($updatesql);
}
/**
* Get a context instance as an object, from a given context id.
*
* @static
* @param int $id context id
* @param int $strictness IGNORE_MISSING means compatible mode, false returned if record not found, debug message if more found;
* MUST_EXIST means throw exception if no record found
* @return context|bool the context object or false if not found
*/
public static function instance_by_id($id, $strictness = MUST_EXIST) {
global $DB;
if (get_called_class() !== 'context' and get_called_class() !== 'context_helper') {
// some devs might confuse context->id and instanceid, better prevent these mistakes completely
throw new coding_exception('use only context::instance_by_id() for real context levels use ::instance() methods');
}
if ($id == SYSCONTEXTID) {
return context_system::instance(0, $strictness);
}
if (is_array($id) or is_object($id) or empty($id)) {
throw new coding_exception('Invalid context id specified context::instance_by_id()');
}
if ($context = context::cache_get_by_id($id)) {
return $context;
}
if ($record = $DB->get_record('context', array('id'=>$id), '*', $strictness)) {
return context::create_instance_from_record($record);
}
return false;
}
/**
* Update context info after moving context in the tree structure.
*
* @param context $newparent
* @return void
*/
public function update_moved(context $newparent) {
global $DB;
$frompath = $this->_path;
$newpath = $newparent->path . '/' . $this->_id;
$trans = $DB->start_delegated_transaction();
$setdepth = '';
if (($newparent->depth +1) != $this->_depth) {
$diff = $newparent->depth - $this->_depth + 1;
$setdepth = ", depth = depth + $diff";
}
$sql = "UPDATE {context}
SET path = ?
$setdepth
WHERE id = ?";
$params = array($newpath, $this->_id);
$DB->execute($sql, $params);
$this->_path = $newpath;
$this->_depth = $newparent->depth + 1;
$sql = "UPDATE {context}
SET path = ".$DB->sql_concat("?", $DB->sql_substr("path", strlen($frompath)+1))."
$setdepth
WHERE path LIKE ?";
$params = array($newpath, "{$frompath}/%");
$DB->execute($sql, $params);
$this->mark_dirty();
context::reset_caches();
$trans->allow_commit();
}
/**
* Set whether this context has been locked or not.
*
* @param bool $locked
* @return $this
*/
public function set_locked(bool $locked) {
global $DB;
if ($this->_locked == $locked) {
return $this;
}
$this->_locked = $locked;
$DB->set_field('context', 'locked', (int) $locked, ['id' => $this->id]);
$this->mark_dirty();
if ($locked) {
$eventname = '\\core\\event\\context_locked';
} else {
$eventname = '\\core\\event\\context_unlocked';
}
$event = $eventname::create(['context' => $this, 'objectid' => $this->id]);
$event->trigger();
self::reset_caches();
return $this;
}
/**
* Remove all context path info and optionally rebuild it.
*
* @param bool $rebuild
* @return void
*/
public function reset_paths($rebuild = true) {
global $DB;
if ($this->_path) {
$this->mark_dirty();
}
$DB->set_field_select('context', 'depth', 0, "path LIKE '%/$this->_id/%'");
$DB->set_field_select('context', 'path', NULL, "path LIKE '%/$this->_id/%'");
if ($this->_contextlevel != CONTEXT_SYSTEM) {
$DB->set_field('context', 'depth', 0, array('id'=>$this->_id));
$DB->set_field('context', 'path', NULL, array('id'=>$this->_id));
$this->_depth = 0;
$this->_path = null;
}
if ($rebuild) {
context_helper::build_all_paths(false);
}
context::reset_caches();
}
/**
* Delete all data linked to content, do not delete the context record itself
*/
public function delete_content() {
global $CFG, $DB;
blocks_delete_all_for_context($this->_id);
filter_delete_all_for_context($this->_id);
require_once($CFG->dirroot . '/comment/lib.php');
comment::delete_comments(array('contextid'=>$this->_id));
require_once($CFG->dirroot.'/rating/lib.php');
$delopt = new stdclass();
$delopt->contextid = $this->_id;
$rm = new rating_manager();
$rm->delete_ratings($delopt);
// delete all files attached to this context
$fs = get_file_storage();
$fs->delete_area_files($this->_id);
// Delete all repository instances attached to this context.
require_once($CFG->dirroot . '/repository/lib.php');
repository::delete_all_for_context($this->_id);
// delete all advanced grading data attached to this context
require_once($CFG->dirroot.'/grade/grading/lib.php');
grading_manager::delete_all_for_context($this->_id);
// now delete stuff from role related tables, role_unassign_all
// and unenrol should be called earlier to do proper cleanup
$DB->delete_records('role_assignments', array('contextid'=>$this->_id));
$DB->delete_records('role_names', array('contextid'=>$this->_id));
$this->delete_capabilities();
}
/**
* Unassign all capabilities from a context.
*/
public function delete_capabilities() {
global $DB;
$ids = $DB->get_fieldset_select('role_capabilities', 'DISTINCT roleid', 'contextid = ?', array($this->_id));
if ($ids) {
$DB->delete_records('role_capabilities', array('contextid' => $this->_id));
// Reset any cache of these roles, including MUC.
accesslib_clear_role_cache($ids);
}
}
/**
* Delete the context content and the context record itself
*/
public function delete() {
global $DB;
if ($this->_contextlevel <= CONTEXT_SYSTEM) {
throw new coding_exception('Cannot delete system context');
}
// double check the context still exists
if (!$DB->record_exists('context', array('id'=>$this->_id))) {
context::cache_remove($this);
return;
}
$this->delete_content();
$DB->delete_records('context', array('id'=>$this->_id));
// purge static context cache if entry present
context::cache_remove($this);
// Inform search engine to delete data related to this context.
\core_search\manager::context_deleted($this);
}
// ====== context level related methods ======
/**
* Utility method for context creation
*
* @static
* @param int $contextlevel
* @param int $instanceid
* @param string $parentpath
* @return stdClass context record
*/
protected static function insert_context_record($contextlevel, $instanceid, $parentpath) {
global $DB;
$record = new stdClass();
$record->contextlevel = $contextlevel;
$record->instanceid = $instanceid;
$record->depth = 0;
$record->path = null; //not known before insert
$record->locked = 0;
$record->id = $DB->insert_record('context', $record);
// now add path if known - it can be added later
if (!is_null($parentpath)) {
$record->path = $parentpath.'/'.$record->id;
$record->depth = substr_count($record->path, '/');
$DB->update_record('context', $record);
}
return $record;
}
/**
* Returns human readable context identifier.
*
* @param boolean $withprefix whether to prefix the name of the context with the
* type of context, e.g. User, Course, Forum, etc.
* @param boolean $short whether to use the short name of the thing. Only applies
* to course contexts
* @return string the human readable context name.
*/
public function get_context_name($withprefix = true, $short = false) {
// must be implemented in all context levels
throw new coding_exception('can not get name of abstract context');
}
/**
* Whether the current context is locked.
*
* @return bool
*/
public function is_locked() {
if ($this->_locked) {
return true;
}
if ($parent = $this->get_parent_context()) {
return $parent->is_locked();
}
return false;
}
/**
* Returns the most relevant URL for this context.
*
* @return moodle_url
*/
public abstract function get_url();
/**
* Returns array of relevant context capability records.
*
* @return array
*/
public abstract function get_capabilities();
/**
* Recursive function which, given a context, find all its children context ids.
*
* For course category contexts it will return immediate children and all subcategory contexts.
* It will NOT recurse into courses or subcategories categories.
* If you want to do that, call it on the returned courses/categories.
*
* When called for a course context, it will return the modules and blocks
* displayed in the course page and blocks displayed on the module pages.
*
* If called on a user/course/module context it _will_ populate the cache with the appropriate
* contexts ;-)
*
* @return array Array of child records
*/
public function get_child_contexts() {
global $DB;
if (empty($this->_path) or empty($this->_depth)) {
debugging('Can not find child contexts of context '.$this->_id.' try rebuilding of context paths');
return array();
}
$sql = "SELECT ctx.*
FROM {context} ctx
WHERE ctx.path LIKE ?";
$params = array($this->_path.'/%');
$records = $DB->get_records_sql($sql, $params);
$result = array();
foreach ($records as $record) {
$result[$record->id] = context::create_instance_from_record($record);
}
return $result;
}
/**
* Returns parent contexts of this context in reversed order, i.e. parent first,
* then grand parent, etc.
*
* @param bool $includeself true means include self too
* @return array of context instances
*/
public function get_parent_contexts($includeself = false) {
if (!$contextids = $this->get_parent_context_ids($includeself)) {
return array();
}
// Preload the contexts to reduce DB calls.
context_helper::preload_contexts_by_id($contextids);
$result = array();
foreach ($contextids as $contextid) {
$parent = context::instance_by_id($contextid, MUST_EXIST);
$result[$parent->id] = $parent;
}
return $result;
}
/**
* Returns parent context ids of this context in reversed order, i.e. parent first,
* then grand parent, etc.
*
* @param bool $includeself true means include self too
* @return array of context ids
*/
public function get_parent_context_ids($includeself = false) {
if (empty($this->_path)) {
return array();
}
$parentcontexts = trim($this->_path, '/'); // kill leading slash
$parentcontexts = explode('/', $parentcontexts);
if (!$includeself) {
array_pop($parentcontexts); // and remove its own id
}
return array_reverse($parentcontexts);
}
/**
* Returns parent context paths of this context.
*
* @param bool $includeself true means include self too
* @return array of context paths
*/
public function get_parent_context_paths($includeself = false) {
if (empty($this->_path)) {
return array();
}
$contextids = explode('/', $this->_path);
$path = '';
$paths = array();
foreach ($contextids as $contextid) {
if ($contextid) {
$path .= '/' . $contextid;
$paths[$contextid] = $path;
}
}
if (!$includeself) {
unset($paths[$this->_id]);
}
return $paths;
}
/**
* Returns parent context
*
* @return context
*/
public function get_parent_context() {
if (empty($this->_path) or $this->_id == SYSCONTEXTID) {
return false;
}
$parentcontexts = trim($this->_path, '/'); // kill leading slash
$parentcontexts = explode('/', $parentcontexts);
array_pop($parentcontexts); // self
$contextid = array_pop($parentcontexts); // immediate parent
return context::instance_by_id($contextid, MUST_EXIST);
}
/**
* Is this context part of any course? If yes return course context.
*
* @param bool $strict true means throw exception if not found, false means return false if not found
* @return context_course context of the enclosing course, null if not found or exception
*/
public function get_course_context($strict = true) {
if ($strict) {
throw new coding_exception('Context does not belong to any course.');
} else {
return false;
}
}
/**
* Returns sql necessary for purging of stale context instances.
*
* @static
* @return string cleanup SQL
*/
protected static function get_cleanup_sql() {
throw new coding_exception('get_cleanup_sql() method must be implemented in all context levels');
}
/**
* Rebuild context paths and depths at context level.
*
* @static
* @param bool $force
* @return void
*/
protected static function build_paths($force) {
throw new coding_exception('build_paths() method must be implemented in all context levels');
}
/**
* Create missing context instances at given level
*
* @static
* @return void
*/
protected static function create_level_instances() {
throw new coding_exception('create_level_instances() method must be implemented in all context levels');
}
/**
* Reset all cached permissions and definitions if the necessary.
* @return void
*/
public function reload_if_dirty() {
global $ACCESSLIB_PRIVATE, $USER;
// Load dirty contexts list if needed
if (CLI_SCRIPT) {
if (!isset($ACCESSLIB_PRIVATE->dirtycontexts)) {
// we do not load dirty flags in CLI and cron
$ACCESSLIB_PRIVATE->dirtycontexts = array();
}
} else {
if (!isset($USER->access['time'])) {
// Nothing has been loaded yet, so we do not need to check dirty flags now.
return;
}
// From skodak: No idea why -2 is there, server cluster time difference maybe...
$changedsince = $USER->access['time'] - 2;
if (!isset($ACCESSLIB_PRIVATE->dirtycontexts)) {
$ACCESSLIB_PRIVATE->dirtycontexts = get_cache_flags('accesslib/dirtycontexts', $changedsince);
}
if (!isset($ACCESSLIB_PRIVATE->dirtyusers[$USER->id])) {
$ACCESSLIB_PRIVATE->dirtyusers[$USER->id] = get_cache_flag('accesslib/dirtyusers', $USER->id, $changedsince);
}
}
$dirty = false;
if (!empty($ACCESSLIB_PRIVATE->dirtyusers[$USER->id])) {
$dirty = true;
} else if (!empty($ACCESSLIB_PRIVATE->dirtycontexts)) {
$paths = $this->get_parent_context_paths(true);
foreach ($paths as $path) {
if (isset($ACCESSLIB_PRIVATE->dirtycontexts[$path])) {
$dirty = true;
break;
}
}
}
if ($dirty) {
// Reload all capabilities of USER and others - preserving loginas, roleswitches, etc.
// Then cleanup any marks of dirtyness... at least from our short term memory!
reload_all_capabilities();
}
}
/**
* Mark a context as dirty (with timestamp) so as to force reloading of the context.
*/
public function mark_dirty() {
global $CFG, $USER, $ACCESSLIB_PRIVATE;
if (during_initial_install()) {
return;
}
// only if it is a non-empty string
if (is_string($this->_path) && $this->_path !== '') {
set_cache_flag('accesslib/dirtycontexts', $this->_path, 1, time()+$CFG->sessiontimeout);
if (isset($ACCESSLIB_PRIVATE->dirtycontexts)) {
$ACCESSLIB_PRIVATE->dirtycontexts[$this->_path] = 1;
} else {
if (CLI_SCRIPT) {
$ACCESSLIB_PRIVATE->dirtycontexts = array($this->_path => 1);
} else {
if (isset($USER->access['time'])) {
$ACCESSLIB_PRIVATE->dirtycontexts = get_cache_flags('accesslib/dirtycontexts', $USER->access['time']-2);
} else {
$ACCESSLIB_PRIVATE->dirtycontexts = array($this->_path => 1);
}
// flags not loaded yet, it will be done later in $context->reload_if_dirty()
}
}
}
}
}
/**
* Context maintenance and helper methods.
*
* This is "extends context" is a bloody hack that tires to work around the deficiencies
* in the "protected" keyword in PHP, this helps us to hide all the internals of context
* level implementation from the rest of code, the code completion returns what developers need.
*
* Thank you Tim Hunt for helping me with this nasty trick.
*
* @package core_access
* @category access
* @copyright Petr Skoda {@link http://skodak.org}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
* @since Moodle 2.2
*/
class context_helper extends context {
/**
* @var array An array mapping context levels to classes
*/
private static $alllevels;
/**
* Instance does not make sense here, only static use
*/
protected function __construct() {
}
/**
* Reset internal context levels array.
*/
public static function reset_levels() {
self::$alllevels = null;
}
/**
* Initialise context levels, call before using self::$alllevels.
*/
private static function init_levels() {
global $CFG;
if (isset(self::$alllevels)) {
return;
}
self::$alllevels = array(
CONTEXT_SYSTEM => 'context_system',
CONTEXT_USER => 'context_user',
CONTEXT_COURSECAT => 'context_coursecat',
CONTEXT_COURSE => 'context_course',
CONTEXT_MODULE => 'context_module',
CONTEXT_BLOCK => 'context_block',
);
if (empty($CFG->custom_context_classes)) {
return;
}
$levels = $CFG->custom_context_classes;
if (!is_array($levels)) {
$levels = @unserialize($levels);
}
if (!is_array($levels)) {
debugging('Invalid $CFG->custom_context_classes detected, value ignored.', DEBUG_DEVELOPER);
return;
}
// Unsupported custom levels, use with care!!!
foreach ($levels as $level => $classname) {
self::$alllevels[$level] = $classname;
}
ksort(self::$alllevels);
}
/**
* Returns a class name of the context level class
*
* @static
* @param int $contextlevel (CONTEXT_SYSTEM, etc.)
* @return string class name of the context class
*/
public static function get_class_for_level($contextlevel) {
self::init_levels();
if (isset(self::$alllevels[$contextlevel])) {
return self::$alllevels[$contextlevel];
} else {
throw new coding_exception('Invalid context level specified');
}
}
/**
* Returns a list of all context levels
*
* @static
* @return array int=>string (level=>level class name)
*/
public static function get_all_levels() {
self::init_levels();
return self::$alllevels;
}
/**
* Remove stale contexts that belonged to deleted instances.
* Ideally all code should cleanup contexts properly, unfortunately accidents happen...
*
* @static
* @return void
*/
public static function cleanup_instances() {
global $DB;
self::init_levels();
$sqls = array();
foreach (self::$alllevels as $level=>$classname) {
$sqls[] = $classname::get_cleanup_sql();
}
$sql = implode(" UNION ", $sqls);
// it is probably better to use transactions, it might be faster too
$transaction = $DB->start_delegated_transaction();
$rs = $DB->get_recordset_sql($sql);
foreach ($rs as $record) {
$context = context::create_instance_from_record($record);
$context->delete();
}
$rs->close();
$transaction->allow_commit();
}
/**
* Create all context instances at the given level and above.
*
* @static
* @param int $contextlevel null means all levels
* @param bool $buildpaths
* @return void
*/
public static function create_instances($contextlevel = null, $buildpaths = true) {
self::init_levels();
foreach (self::$alllevels as $level=>$classname) {
if ($contextlevel and $level > $contextlevel) {
// skip potential sub-contexts
continue;
}
$classname::create_level_instances();
if ($buildpaths) {
$classname::build_paths(false);
}
}
}
/**
* Rebuild paths and depths in all context levels.
*
* @static
* @param bool $force false means add missing only
* @return void
*/
public static function build_all_paths($force = false) {
self::init_levels();
foreach (self::$alllevels as $classname) {
$classname::build_paths($force);
}
// reset static course cache - it might have incorrect cached data
accesslib_clear_all_caches(true);
}
/**
* Resets the cache to remove all data.
* @static
*/
public static function reset_caches() {
context::reset_caches();
}
/**
* Returns all fields necessary for context preloading from user $rec.
*
* This helps with performance when dealing with hundreds of contexts.
*
* @static
* @param string $tablealias context table alias in the query
* @return array (table.column=>alias, ...)
*/
public static function get_preload_record_columns($tablealias) {
return [
"$tablealias.id" => "ctxid",
"$tablealias.path" => "ctxpath",
"$tablealias.depth" => "ctxdepth",
"$tablealias.contextlevel" => "ctxlevel",
"$tablealias.instanceid" => "ctxinstance",
"$tablealias.locked" => "ctxlocked",
];
}
/**
* Returns all fields necessary for context preloading from user $rec.
*
* This helps with performance when dealing with hundreds of contexts.
*
* @static
* @param string $tablealias context table alias in the query
* @return string
*/
public static function get_preload_record_columns_sql($tablealias) {
return "$tablealias.id AS ctxid, " .
"$tablealias.path AS ctxpath, " .
"$tablealias.depth AS ctxdepth, " .
"$tablealias.contextlevel AS ctxlevel, " .
"$tablealias.instanceid AS ctxinstance, " .
"$tablealias.locked AS ctxlocked";
}
/**
* Preloads context information from db record and strips the cached info.
*
* The db request has to contain all columns from context_helper::get_preload_record_columns().
*
* @static
* @param stdClass $rec
* @return void (modifies $rec)
*/
public static function preload_from_record(stdClass $rec) {
context::preload_from_record($rec);
}
/**
* Preload a set of contexts using their contextid.
*
* @param array $contextids
*/
public static function preload_contexts_by_id(array $contextids) {
global $DB;
// Determine which contexts are not already cached.
$tofetch = [];
foreach ($contextids as $contextid) {
if (!self::cache_get_by_id($contextid)) {
$tofetch[] = $contextid;
}
}
if (count($tofetch) > 1) {
// There are at least two to fetch.
// There is no point only fetching a single context as this would be no more efficient than calling the existing code.
list($insql, $inparams) = $DB->get_in_or_equal($tofetch, SQL_PARAMS_NAMED);
$ctxs = $DB->get_records_select('context', "id {$insql}", $inparams, '',
\context_helper::get_preload_record_columns_sql('{context}'));
foreach ($ctxs as $ctx) {
self::preload_from_record($ctx);
}
}
}
/**
* Preload all contexts instances from course.
*
* To be used if you expect multiple queries for course activities...
*
* @static
* @param int $courseid
*/
public static function preload_course($courseid) {
// Users can call this multiple times without doing any harm
if (isset(context::$cache_preloaded[$courseid])) {
return;
}
$coursecontext = context_course::instance($courseid);
$coursecontext->get_child_contexts();
context::$cache_preloaded[$courseid] = true;
}
/**
* Delete context instance
*
* @static
* @param int $contextlevel
* @param int $instanceid
* @return void
*/
public static function delete_instance($contextlevel, $instanceid) {
global $DB;
// double check the context still exists
if ($record = $DB->get_record('context', array('contextlevel'=>$contextlevel, 'instanceid'=>$instanceid))) {
$context = context::create_instance_from_record($record);
$context->delete();
} else {
// we should try to purge the cache anyway
}
}
/**
* Returns the name of specified context level
*
* @static
* @param int $contextlevel
* @return string name of the context level
*/
public static function get_level_name($contextlevel) {
$classname = context_helper::get_class_for_level($contextlevel);
return $classname::get_level_name();
}
/**
* not used
*/
public function get_url() {
}
/**
* not used
*/
public function get_capabilities() {
}
}
/**
* System context class
*
* @package core_access
* @category access
* @copyright Petr Skoda {@link http://skodak.org}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
* @since Moodle 2.2
*/
class context_system extends context {
/**
* Please use context_system::instance() if you need the instance of context.
*
* @param stdClass $record
*/
protected function __construct(stdClass $record) {
parent::__construct($record);
if ($record->contextlevel != CONTEXT_SYSTEM) {
throw new coding_exception('Invalid $record->contextlevel in context_system constructor.');
}
}
/**
* Returns human readable context level name.
*
* @static
* @return string the human readable context level name.
*/
public static function get_level_name() {
return get_string('coresystem');
}
/**
* Returns human readable context identifier.
*
* @param boolean $withprefix does not apply to system context
* @param boolean $short does not apply to system context
* @return string the human readable context name.
*/
public function get_context_name($withprefix = true, $short = false) {
return self::get_level_name();
}
/**
* Returns the most relevant URL for this context.
*
* @return moodle_url
*/
public function get_url() {
return new moodle_url('/');
}
/**
* Returns array of relevant context capability records.
*
* @return array
*/
public function get_capabilities() {
global $DB;
$sort = 'ORDER BY contextlevel,component,name'; // To group them sensibly for display
$params = array();
$sql = "SELECT *
FROM {capabilities}";
return $DB->get_records_sql($sql.' '.$sort, $params);
}
/**
* Create missing context instances at system context
* @static
*/
protected static function create_level_instances() {
// nothing to do here, the system context is created automatically in installer
self::instance(0);
}
/**
* Returns system context instance.
*
* @static
* @param int $instanceid should be 0
* @param int $strictness
* @param bool $cache
* @return context_system context instance
*/
public static function instance($instanceid = 0, $strictness = MUST_EXIST, $cache = true) {
global $DB;
if ($instanceid != 0) {
debugging('context_system::instance(): invalid $id parameter detected, should be 0');
}
if (defined('SYSCONTEXTID') and $cache) { // dangerous: define this in config.php to eliminate 1 query/page
if (!isset(context::$systemcontext)) {
$record = new stdClass();
$record->id = SYSCONTEXTID;
$record->contextlevel = CONTEXT_SYSTEM;
$record->instanceid = 0;
$record->path = '/'.SYSCONTEXTID;
$record->depth = 1;
$record->locked = 0;
context::$systemcontext = new context_system($record);
}
return context::$systemcontext;
}
try {
// We ignore the strictness completely because system context must exist except during install.
$record = $DB->get_record('context', array('contextlevel'=>CONTEXT_SYSTEM), '*', MUST_EXIST);
} catch (dml_exception $e) {
//table or record does not exist
if (!during_initial_install()) {
// do not mess with system context after install, it simply must exist
throw $e;
}
$record = null;
}
if (!$record) {
$record = new stdClass();
$record->contextlevel = CONTEXT_SYSTEM;
$record->instanceid = 0;
$record->depth = 1;
$record->path = null; // Not known before insert.
$record->locked = 0;
try {
if ($DB->count_records('context')) {
// contexts already exist, this is very weird, system must be first!!!
return null;
}
if (defined('SYSCONTEXTID')) {
// this would happen only in unittest on sites that went through weird 1.7 upgrade
$record->id = SYSCONTEXTID;
$DB->import_record('context', $record);
$DB->get_manager()->reset_sequence('context');
} else {
$record->id = $DB->insert_record('context', $record);
}
} catch (dml_exception $e) {
// can not create context - table does not exist yet, sorry
return null;
}
}
if ($record->instanceid != 0) {
// this is very weird, somebody must be messing with context table
debugging('Invalid system context detected');
}
if ($record->depth != 1 or $record->path != '/'.$record->id) {
// fix path if necessary, initial install or path reset
$record->depth = 1;
$record->path = '/'.$record->id;
$DB->update_record('context', $record);
}
if (empty($record->locked)) {
$record->locked = 0;
}
if (!defined('SYSCONTEXTID')) {
define('SYSCONTEXTID', $record->id);
}
context::$systemcontext = new context_system($record);
return context::$systemcontext;
}
/**
* Returns all site contexts except the system context, DO NOT call on production servers!!
*
* Contexts are not cached.
*
* @return array
*/
public function get_child_contexts() {
global $DB;
debugging('Fetching of system context child courses is strongly discouraged on production servers (it may eat all available memory)!');
// Just get all the contexts except for CONTEXT_SYSTEM level
// and hope we don't OOM in the process - don't cache
$sql = "SELECT c.*
FROM {context} c
WHERE contextlevel > ".CONTEXT_SYSTEM;
$records = $DB->get_records_sql($sql);
$result = array();
foreach ($records as $record) {
$result[$record->id] = context::create_instance_from_record($record);
}
return $result;
}
/**
* Returns sql necessary for purging of stale context instances.
*
* @static
* @return string cleanup SQL
*/
protected static function get_cleanup_sql() {
$sql = "
SELECT c.*
FROM {context} c
WHERE 1=2
";
return $sql;
}
/**
* Rebuild context paths and depths at system context level.
*
* @static
* @param bool $force
*/
protected static function build_paths($force) {
global $DB;
/* note: ignore $force here, we always do full test of system context */
// exactly one record must exist
$record = $DB->get_record('context', array('contextlevel'=>CONTEXT_SYSTEM), '*', MUST_EXIST);
if ($record->instanceid != 0) {
debugging('Invalid system context detected');
}
if (defined('SYSCONTEXTID') and $record->id != SYSCONTEXTID) {
debugging('Invalid SYSCONTEXTID detected');
}
if ($record->depth != 1 or $record->path != '/'.$record->id) {
// fix path if necessary, initial install or path reset
$record->depth = 1;
$record->path = '/'.$record->id;
$DB->update_record('context', $record);
}
}
/**
* Set whether this context has been locked or not.
*
* @param bool $locked
* @return $this
*/
public function set_locked(bool $locked) {
throw new \coding_exception('It is not possible to lock the system context');
return $this;
}
}
/**
* User context class
*
* @package core_access
* @category access
* @copyright Petr Skoda {@link http://skodak.org}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
* @since Moodle 2.2
*/
class context_user extends context {
/**
* Please use context_user::instance($userid) if you need the instance of context.
* Alternatively if you know only the context id use context::instance_by_id($contextid)
*
* @param stdClass $record
*/
protected function __construct(stdClass $record) {
parent::__construct($record);
if ($record->contextlevel != CONTEXT_USER) {
throw new coding_exception('Invalid $record->contextlevel in context_user constructor.');
}
}
/**
* Returns human readable context level name.
*
* @static
* @return string the human readable context level name.
*/
public static function get_level_name() {
return get_string('user');
}
/**
* Returns human readable context identifier.
*
* @param boolean $withprefix whether to prefix the name of the context with User
* @param boolean $short does not apply to user context
* @return string the human readable context name.
*/
public function get_context_name($withprefix = true, $short = false) {
global $DB;
$name = '';
if ($user = $DB->get_record('user', array('id'=>$this->_instanceid, 'deleted'=>0))) {
if ($withprefix){
$name = get_string('user').': ';
}
$name .= fullname($user);
}
return $name;
}
/**
* Returns the most relevant URL for this context.
*
* @return moodle_url
*/
public function get_url() {
global $COURSE;
if ($COURSE->id == SITEID) {
$url = new moodle_url('/user/profile.php', array('id'=>$this->_instanceid));
} else {
$url = new moodle_url('/user/view.php', array('id'=>$this->_instanceid, 'courseid'=>$COURSE->id));
}
return $url;
}
/**
* Returns array of relevant context capability records.
*
* @return array
*/
public function get_capabilities() {
global $DB;
$sort = 'ORDER BY contextlevel,component,name'; // To group them sensibly for display
$extracaps = array('moodle/grade:viewall');
list($extra, $params) = $DB->get_in_or_equal($extracaps, SQL_PARAMS_NAMED, 'cap');
$sql = "SELECT *
FROM {capabilities}
WHERE contextlevel = ".CONTEXT_USER."
OR name $extra";
return $records = $DB->get_records_sql($sql.' '.$sort, $params);
}
/**
* Returns user context instance.
*
* @static
* @param int $userid id from {user} table
* @param int $strictness
* @return context_user context instance
*/
public static function instance($userid, $strictness = MUST_EXIST) {
global $DB;
if ($context = context::cache_get(CONTEXT_USER, $userid)) {
return $context;
}
if (!$record = $DB->get_record('context', array('contextlevel' => CONTEXT_USER, 'instanceid' => $userid))) {
if ($user = $DB->get_record('user', array('id' => $userid, 'deleted' => 0), 'id', $strictness)) {
$record = context::insert_context_record(CONTEXT_USER, $user->id, '/'.SYSCONTEXTID, 0);
}
}
if ($record) {
$context = new context_user($record);
context::cache_add($context);
return $context;
}
return false;
}
/**
* Create missing context instances at user context level
* @static
*/
protected static function create_level_instances() {
global $DB;
$sql = "SELECT ".CONTEXT_USER.", u.id
FROM {user} u
WHERE u.deleted = 0
AND NOT EXISTS (SELECT 'x'
FROM {context} cx
WHERE u.id = cx.instanceid AND cx.contextlevel=".CONTEXT_USER.")";
$contextdata = $DB->get_recordset_sql($sql);
foreach ($contextdata as $context) {
context::insert_context_record(CONTEXT_USER, $context->id, null);
}
$contextdata->close();
}
/**
* Returns sql necessary for purging of stale context instances.
*
* @static
* @return string cleanup SQL
*/
protected static function get_cleanup_sql() {
$sql = "
SELECT c.*
FROM {context} c
LEFT OUTER JOIN {user} u ON (c.instanceid = u.id AND u.deleted = 0)
WHERE u.id IS NULL AND c.contextlevel = ".CONTEXT_USER."
";
return $sql;
}
/**
* Rebuild context paths and depths at user context level.
*
* @static
* @param bool $force
*/
protected static function build_paths($force) {
global $DB;
// First update normal users.
$path = $DB->sql_concat('?', 'id');
$pathstart = '/' . SYSCONTEXTID . '/';
$params = array($pathstart);
if ($force) {
$where = "depth <> 2 OR path IS NULL OR path <> ({$path})";
$params[] = $pathstart;
} else {
$where = "depth = 0 OR path IS NULL";
}
$sql = "UPDATE {context}
SET depth = 2,
path = {$path}
WHERE contextlevel = " . CONTEXT_USER . "
AND ($where)";
$DB->execute($sql, $params);
}
}
/**
* Course category context class
*
* @package core_access
* @category access
* @copyright Petr Skoda {@link http://skodak.org}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
* @since Moodle 2.2
*/
class context_coursecat extends context {
/**
* Please use context_coursecat::instance($coursecatid) if you need the instance of context.
* Alternatively if you know only the context id use context::instance_by_id($contextid)
*
* @param stdClass $record
*/
protected function __construct(stdClass $record) {
parent::__construct($record);
if ($record->contextlevel != CONTEXT_COURSECAT) {
throw new coding_exception('Invalid $record->contextlevel in context_coursecat constructor.');
}
}
/**
* Returns human readable context level name.
*
* @static
* @return string the human readable context level name.
*/
public static function get_level_name() {
return get_string('category');
}
/**
* Returns human readable context identifier.
*
* @param boolean $withprefix whether to prefix the name of the context with Category
* @param boolean $short does not apply to course categories
* @return string the human readable context name.
*/
public function get_context_name($withprefix = true, $short = false) {
global $DB;
$name = '';
if ($category = $DB->get_record('course_categories', array('id'=>$this->_instanceid))) {
if ($withprefix){
$name = get_string('category').': ';
}
$name .= format_string($category->name, true, array('context' => $this));
}
return $name;
}
/**
* Returns the most relevant URL for this context.
*
* @return moodle_url
*/
public function get_url() {
return new moodle_url('/course/index.php', array('categoryid' => $this->_instanceid));
}
/**
* Returns array of relevant context capability records.
*
* @return array
*/
public function get_capabilities() {
global $DB;
$sort = 'ORDER BY contextlevel,component,name'; // To group them sensibly for display
$params = array();
$sql = "SELECT *
FROM {capabilities}
WHERE contextlevel IN (".CONTEXT_COURSECAT.",".CONTEXT_COURSE.",".CONTEXT_MODULE.",".CONTEXT_BLOCK.")";
return $DB->get_records_sql($sql.' '.$sort, $params);
}
/**
* Returns course category context instance.
*
* @static
* @param int $categoryid id from {course_categories} table
* @param int $strictness
* @return context_coursecat context instance
*/
public static function instance($categoryid, $strictness = MUST_EXIST) {
global $DB;
if ($context = context::cache_get(CONTEXT_COURSECAT, $categoryid)) {
return $context;
}
if (!$record = $DB->get_record('context', array('contextlevel' => CONTEXT_COURSECAT, 'instanceid' => $categoryid))) {
if ($category = $DB->get_record('course_categories', array('id' => $categoryid), 'id,parent', $strictness)) {
if ($category->parent) {
$parentcontext = context_coursecat::instance($category->parent);
$record = context::insert_context_record(CONTEXT_COURSECAT, $category->id, $parentcontext->path);
} else {
$record = context::insert_context_record(CONTEXT_COURSECAT, $category->id, '/'.SYSCONTEXTID, 0);
}
}
}
if ($record) {
$context = new context_coursecat($record);
context::cache_add($context);
return $context;
}
return false;
}
/**
* Returns immediate child contexts of category and all subcategories,
* children of subcategories and courses are not returned.
*
* @return array
*/
public function get_child_contexts() {
global $DB;
if (empty($this->_path) or empty($this->_depth)) {
debugging('Can not find child contexts of context '.$this->_id.' try rebuilding of context paths');
return array();
}
$sql = "SELECT ctx.*
FROM {context} ctx
WHERE ctx.path LIKE ? AND (ctx.depth = ? OR ctx.contextlevel = ?)";
$params = array($this->_path.'/%', $this->depth+1, CONTEXT_COURSECAT);
$records = $DB->get_records_sql($sql, $params);
$result = array();
foreach ($records as $record) {
$result[$record->id] = context::create_instance_from_record($record);
}
return $result;
}
/**
* Create missing context instances at course category context level
* @static
*/
protected static function create_level_instances() {
global $DB;
$sql = "SELECT ".CONTEXT_COURSECAT.", cc.id
FROM {course_categories} cc
WHERE NOT EXISTS (SELECT 'x'
FROM {context} cx
WHERE cc.id = cx.instanceid AND cx.contextlevel=".CONTEXT_COURSECAT.")";
$contextdata = $DB->get_recordset_sql($sql);
foreach ($contextdata as $context) {
context::insert_context_record(CONTEXT_COURSECAT, $context->id, null);
}
$contextdata->close();
}
/**
* Returns sql necessary for purging of stale context instances.
*
* @static
* @return string cleanup SQL
*/
protected static function get_cleanup_sql() {
$sql = "
SELECT c.*
FROM {context} c
LEFT OUTER JOIN {course_categories} cc ON c.instanceid = cc.id
WHERE cc.id IS NULL AND c.contextlevel = ".CONTEXT_COURSECAT."
";
return $sql;
}
/**
* Rebuild context paths and depths at course category context level.
*
* @static
* @param bool $force
*/
protected static function build_paths($force) {
global $DB;
if ($force or $DB->record_exists_select('context', "contextlevel = ".CONTEXT_COURSECAT." AND (depth = 0 OR path IS NULL)")) {
if ($force) {
$ctxemptyclause = $emptyclause = '';
} else {
$ctxemptyclause = "AND (ctx.path IS NULL OR ctx.depth = 0)";
$emptyclause = "AND ({context}.path IS NULL OR {context}.depth = 0)";
}
$base = '/'.SYSCONTEXTID;
// Normal top level categories
$sql = "UPDATE {context}
SET depth=2,
path=".$DB->sql_concat("'$base/'", 'id')."
WHERE contextlevel=".CONTEXT_COURSECAT."
AND EXISTS (SELECT 'x'
FROM {course_categories} cc
WHERE cc.id = {context}.instanceid AND cc.depth=1)
$emptyclause";
$DB->execute($sql);
// Deeper categories - one query per depthlevel
$maxdepth = $DB->get_field_sql("SELECT MAX(depth) FROM {course_categories}");
for ($n=2; $n<=$maxdepth; $n++) {
$sql = "INSERT INTO {context_temp} (id, path, depth, locked)
SELECT ctx.id, ".$DB->sql_concat('pctx.path', "'/'", 'ctx.id').", pctx.depth+1, ctx.locked
FROM {context} ctx
JOIN {course_categories} cc ON (cc.id = ctx.instanceid AND ctx.contextlevel = ".CONTEXT_COURSECAT." AND cc.depth = $n)
JOIN {context} pctx ON (pctx.instanceid = cc.parent AND pctx.contextlevel = ".CONTEXT_COURSECAT.")
WHERE pctx.path IS NOT NULL AND pctx.depth > 0
$ctxemptyclause";
$trans = $DB->start_delegated_transaction();
$DB->delete_records('context_temp');
$DB->execute($sql);
context::merge_context_temp_table();
$DB->delete_records('context_temp');
$trans->allow_commit();
}
}
}
}
/**
* Course context class
*
* @package core_access
* @category access
* @copyright Petr Skoda {@link http://skodak.org}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
* @since Moodle 2.2
*/
class context_course extends context {
/**
* Please use context_course::instance($courseid) if you need the instance of context.
* Alternatively if you know only the context id use context::instance_by_id($contextid)
*
* @param stdClass $record
*/
protected function __construct(stdClass $record) {
parent::__construct($record);
if ($record->contextlevel != CONTEXT_COURSE) {
throw new coding_exception('Invalid $record->contextlevel in context_course constructor.');
}
}
/**
* Returns human readable context level name.
*
* @static
* @return string the human readable context level name.
*/
public static function get_level_name() {
return get_string('course');
}
/**
* Returns human readable context identifier.
*
* @param boolean $withprefix whether to prefix the name of the context with Course
* @param boolean $short whether to use the short name of the thing.
* @return string the human readable context name.
*/
public function get_context_name($withprefix = true, $short = false) {
global $DB;
$name = '';
if ($this->_instanceid == SITEID) {
$name = get_string('frontpage', 'admin');
} else {
if ($course = $DB->get_record('course', array('id'=>$this->_instanceid))) {
if ($withprefix){
$name = get_string('course').': ';
}
if ($short){
$name .= format_string($course->shortname, true, array('context' => $this));
} else {
$name .= format_string(get_course_display_name_for_list($course));
}
}
}
return $name;
}
/**
* Returns the most relevant URL for this context.
*
* @return moodle_url
*/
public function get_url() {
if ($this->_instanceid != SITEID) {
return new moodle_url('/course/view.php', array('id'=>$this->_instanceid));
}
return new moodle_url('/');
}
/**
* Returns array of relevant context capability records.
*
* @return array
*/
public function get_capabilities() {
global $DB;
$sort = 'ORDER BY contextlevel,component,name'; // To group them sensibly for display
$params = array();
$sql = "SELECT *
FROM {capabilities}
WHERE contextlevel IN (".CONTEXT_COURSE.",".CONTEXT_MODULE.",".CONTEXT_BLOCK.")";
return $DB->get_records_sql($sql.' '.$sort, $params);
}
/**
* Is this context part of any course? If yes return course context.
*
* @param bool $strict true means throw exception if not found, false means return false if not found
* @return context_course context of the enclosing course, null if not found or exception
*/
public function get_course_context($strict = true) {
return $this;
}
/**
* Returns course context instance.
*
* @static
* @param int $courseid id from {course} table
* @param int $strictness
* @return context_course context instance
*/
public static function instance($courseid, $strictness = MUST_EXIST) {
global $DB;
if ($context = context::cache_get(CONTEXT_COURSE, $courseid)) {
return $context;
}
if (!$record = $DB->get_record('context', array('contextlevel' => CONTEXT_COURSE, 'instanceid' => $courseid))) {
if ($course = $DB->get_record('course', array('id' => $courseid), 'id,category', $strictness)) {
if ($course->category) {
$parentcontext = context_coursecat::instance($course->category);
$record = context::insert_context_record(CONTEXT_COURSE, $course->id, $parentcontext->path);
} else {
$record = context::insert_context_record(CONTEXT_COURSE, $course->id, '/'.SYSCONTEXTID, 0);
}
}
}
if ($record) {
$context = new context_course($record);
context::cache_add($context);
return $context;
}
return false;
}
/**
* Create missing context instances at course context level
* @static
*/
protected static function create_level_instances() {
global $DB;
$sql = "SELECT ".CONTEXT_COURSE.", c.id
FROM {course} c
WHERE NOT EXISTS (SELECT 'x'
FROM {context} cx
WHERE c.id = cx.instanceid AND cx.contextlevel=".CONTEXT_COURSE.")";
$contextdata = $DB->get_recordset_sql($sql);
foreach ($contextdata as $context) {
context::insert_context_record(CONTEXT_COURSE, $context->id, null);
}
$contextdata->close();
}
/**
* Returns sql necessary for purging of stale context instances.
*
* @static
* @return string cleanup SQL
*/
protected static function get_cleanup_sql() {
$sql = "
SELECT c.*
FROM {context} c
LEFT OUTER JOIN {course} co ON c.instanceid = co.id
WHERE co.id IS NULL AND c.contextlevel = ".CONTEXT_COURSE."
";
return $sql;
}
/**
* Rebuild context paths and depths at course context level.
*
* @static
* @param bool $force
*/
protected static function build_paths($force) {
global $DB;
if ($force or $DB->record_exists_select('context', "contextlevel = ".CONTEXT_COURSE." AND (depth = 0 OR path IS NULL)")) {
if ($force) {
$ctxemptyclause = $emptyclause = '';
} else {
$ctxemptyclause = "AND (ctx.path IS NULL OR ctx.depth = 0)";
$emptyclause = "AND ({context}.path IS NULL OR {context}.depth = 0)";
}
$base = '/'.SYSCONTEXTID;
// Standard frontpage
$sql = "UPDATE {context}
SET depth = 2,
path = ".$DB->sql_concat("'$base/'", 'id')."
WHERE contextlevel = ".CONTEXT_COURSE."
AND EXISTS (SELECT 'x'
FROM {course} c
WHERE c.id = {context}.instanceid AND c.category = 0)
$emptyclause";
$DB->execute($sql);
// standard courses
$sql = "INSERT INTO {context_temp} (id, path, depth, locked)
SELECT ctx.id, ".$DB->sql_concat('pctx.path', "'/'", 'ctx.id').", pctx.depth+1, ctx.locked
FROM {context} ctx
JOIN {course} c ON (c.id = ctx.instanceid AND ctx.contextlevel = ".CONTEXT_COURSE." AND c.category <> 0)
JOIN {context} pctx ON (pctx.instanceid = c.category AND pctx.contextlevel = ".CONTEXT_COURSECAT.")
WHERE pctx.path IS NOT NULL AND pctx.depth > 0
$ctxemptyclause";
$trans = $DB->start_delegated_transaction();
$DB->delete_records('context_temp');
$DB->execute($sql);
context::merge_context_temp_table();
$DB->delete_records('context_temp');
$trans->allow_commit();
}
}
}
/**
* Course module context class
*
* @package core_access
* @category access
* @copyright Petr Skoda {@link http://skodak.org}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
* @since Moodle 2.2
*/
class context_module extends context {
/**
* Please use context_module::instance($cmid) if you need the instance of context.
* Alternatively if you know only the context id use context::instance_by_id($contextid)
*
* @param stdClass $record
*/
protected function __construct(stdClass $record) {
parent::__construct($record);
if ($record->contextlevel != CONTEXT_MODULE) {
throw new coding_exception('Invalid $record->contextlevel in context_module constructor.');
}
}
/**
* Returns human readable context level name.
*
* @static
* @return string the human readable context level name.
*/
public static function get_level_name() {
return get_string('activitymodule');
}
/**
* Returns human readable context identifier.
*
* @param boolean $withprefix whether to prefix the name of the context with the
* module name, e.g. Forum, Glossary, etc.
* @param boolean $short does not apply to module context
* @return string the human readable context name.
*/
public function get_context_name($withprefix = true, $short = false) {
global $DB;
$name = '';
if ($cm = $DB->get_record_sql("SELECT cm.*, md.name AS modname
FROM {course_modules} cm
JOIN {modules} md ON md.id = cm.module
WHERE cm.id = ?", array($this->_instanceid))) {
if ($mod = $DB->get_record($cm->modname, array('id' => $cm->instance))) {
if ($withprefix){
$name = get_string('modulename', $cm->modname).': ';
}
$name .= format_string($mod->name, true, array('context' => $this));
}
}
return $name;
}
/**
* Returns the most relevant URL for this context.
*
* @return moodle_url
*/
public function get_url() {
global $DB;
if ($modname = $DB->get_field_sql("SELECT md.name AS modname
FROM {course_modules} cm
JOIN {modules} md ON md.id = cm.module
WHERE cm.id = ?", array($this->_instanceid))) {
return new moodle_url('/mod/' . $modname . '/view.php', array('id'=>$this->_instanceid));
}
return new moodle_url('/');
}
/**
* Returns array of relevant context capability records.
*
* @return array
*/
public function get_capabilities() {
global $DB, $CFG;
$sort = 'ORDER BY contextlevel,component,name'; // To group them sensibly for display
$cm = $DB->get_record('course_modules', array('id'=>$this->_instanceid));
$module = $DB->get_record('modules', array('id'=>$cm->module));
$subcaps = array();
$modulepath = "{$CFG->dirroot}/mod/{$module->name}";
if (file_exists("{$modulepath}/db/subplugins.json")) {
$subplugins = (array) json_decode(file_get_contents("{$modulepath}/db/subplugins.json"))->plugintypes;
} else if (file_exists("{$modulepath}/db/subplugins.php")) {
debugging('Use of subplugins.php has been deprecated. ' .
'Please update your plugin to provide a subplugins.json file instead.',
DEBUG_DEVELOPER);
$subplugins = array(); // should be redefined in the file
include("{$modulepath}/db/subplugins.php");
}
if (!empty($subplugins)) {
foreach (array_keys($subplugins) as $subplugintype) {
foreach (array_keys(core_component::get_plugin_list($subplugintype)) as $subpluginname) {
$subcaps = array_merge($subcaps, array_keys(load_capability_def($subplugintype.'_'.$subpluginname)));
}
}
}
$modfile = "{$modulepath}/lib.php";
$extracaps = array();
if (file_exists($modfile)) {
include_once($modfile);
$modfunction = $module->name.'_get_extra_capabilities';
if (function_exists($modfunction)) {
$extracaps = $modfunction();
}
}
$extracaps = array_merge($subcaps, $extracaps);
$extra = '';
list($extra, $params) = $DB->get_in_or_equal(
$extracaps, SQL_PARAMS_NAMED, 'cap0', true, '');
if (!empty($extra)) {
$extra = "OR name $extra";
}
// Fetch the list of modules, and remove this one.
$components = \core_component::get_component_list();
$componentnames = $components['mod'];
unset($componentnames["mod_{$module->name}"]);
$componentnames = array_keys($componentnames);
// Exclude all other modules.
list($notcompsql, $notcompparams) = $DB->get_in_or_equal($componentnames, SQL_PARAMS_NAMED, 'notcomp', false);
$params = array_merge($params, $notcompparams);
// Exclude other component submodules.
$i = 0;
$ignorecomponents = [];
foreach ($componentnames as $mod) {
if ($subplugins = \core_component::get_subplugins($mod)) {
foreach (array_keys($subplugins) as $subplugintype) {
$paramname = "notlike{$i}";
$ignorecomponents[] = $DB->sql_like('component', ":{$paramname}", true, true, true);
$params[$paramname] = "{$subplugintype}_%";
$i++;
}
}
}
$notlikesql = "(" . implode(' AND ', $ignorecomponents) . ")";
$sql = "SELECT *
FROM {capabilities}
WHERE (contextlevel = ".CONTEXT_MODULE."
AND component {$notcompsql}
AND {$notlikesql})
$extra";
return $DB->get_records_sql($sql.' '.$sort, $params);
}
/**
* Is this context part of any course? If yes return course context.
*
* @param bool $strict true means throw exception if not found, false means return false if not found
* @return context_course context of the enclosing course, null if not found or exception
*/
public function get_course_context($strict = true) {
return $this->get_parent_context();
}
/**
* Returns module context instance.
*
* @static
* @param int $cmid id of the record from {course_modules} table; pass cmid there, NOT id in the instance column
* @param int $strictness
* @return context_module context instance
*/
public static function instance($cmid, $strictness = MUST_EXIST) {
global $DB;
if ($context = context::cache_get(CONTEXT_MODULE, $cmid)) {
return $context;
}
if (!$record = $DB->get_record('context', array('contextlevel' => CONTEXT_MODULE, 'instanceid' => $cmid))) {
if ($cm = $DB->get_record('course_modules', array('id' => $cmid), 'id,course', $strictness)) {
$parentcontext = context_course::instance($cm->course);
$record = context::insert_context_record(CONTEXT_MODULE, $cm->id, $parentcontext->path);
}
}
if ($record) {
$context = new context_module($record);
context::cache_add($context);
return $context;
}
return false;
}
/**
* Create missing context instances at module context level
* @static
*/
protected static function create_level_instances() {
global $DB;
$sql = "SELECT ".CONTEXT_MODULE.", cm.id
FROM {course_modules} cm
WHERE NOT EXISTS (SELECT 'x'
FROM {context} cx
WHERE cm.id = cx.instanceid AND cx.contextlevel=".CONTEXT_MODULE.")";
$contextdata = $DB->get_recordset_sql($sql);
foreach ($contextdata as $context) {
context::insert_context_record(CONTEXT_MODULE, $context->id, null);
}
$contextdata->close();
}
/**
* Returns sql necessary for purging of stale context instances.
*
* @static
* @return string cleanup SQL
*/
protected static function get_cleanup_sql() {
$sql = "
SELECT c.*
FROM {context} c
LEFT OUTER JOIN {course_modules} cm ON c.instanceid = cm.id
WHERE cm.id IS NULL AND c.contextlevel = ".CONTEXT_MODULE."
";
return $sql;
}
/**
* Rebuild context paths and depths at module context level.
*
* @static
* @param bool $force
*/
protected static function build_paths($force) {
global $DB;
if ($force or $DB->record_exists_select('context', "contextlevel = ".CONTEXT_MODULE." AND (depth = 0 OR path IS NULL)")) {
if ($force) {
$ctxemptyclause = '';
} else {
$ctxemptyclause = "AND (ctx.path IS NULL OR ctx.depth = 0)";
}
$sql = "INSERT INTO {context_temp} (id, path, depth, locked)
SELECT ctx.id, ".$DB->sql_concat('pctx.path', "'/'", 'ctx.id').", pctx.depth+1, ctx.locked
FROM {context} ctx
JOIN {course_modules} cm ON (cm.id = ctx.instanceid AND ctx.contextlevel = ".CONTEXT_MODULE.")
JOIN {context} pctx ON (pctx.instanceid = cm.course AND pctx.contextlevel = ".CONTEXT_COURSE.")
WHERE pctx.path IS NOT NULL AND pctx.depth > 0
$ctxemptyclause";
$trans = $DB->start_delegated_transaction();
$DB->delete_records('context_temp');
$DB->execute($sql);
context::merge_context_temp_table();
$DB->delete_records('context_temp');
$trans->allow_commit();
}
}
}
/**
* Block context class
*
* @package core_access
* @category access
* @copyright Petr Skoda {@link http://skodak.org}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
* @since Moodle 2.2
*/
class context_block extends context {
/**
* Please use context_block::instance($blockinstanceid) if you need the instance of context.
* Alternatively if you know only the context id use context::instance_by_id($contextid)
*
* @param stdClass $record
*/
protected function __construct(stdClass $record) {
parent::__construct($record);
if ($record->contextlevel != CONTEXT_BLOCK) {
throw new coding_exception('Invalid $record->contextlevel in context_block constructor');
}
}
/**
* Returns human readable context level name.
*
* @static
* @return string the human readable context level name.
*/
public static function get_level_name() {
return get_string('block');
}
/**
* Returns human readable context identifier.
*
* @param boolean $withprefix whether to prefix the name of the context with Block
* @param boolean $short does not apply to block context
* @return string the human readable context name.
*/
public function get_context_name($withprefix = true, $short = false) {
global $DB, $CFG;
$name = '';
if ($blockinstance = $DB->get_record('block_instances', array('id'=>$this->_instanceid))) {
global $CFG;
require_once("$CFG->dirroot/blocks/moodleblock.class.php");
require_once("$CFG->dirroot/blocks/$blockinstance->blockname/block_$blockinstance->blockname.php");
$blockname = "block_$blockinstance->blockname";
if ($blockobject = new $blockname()) {
if ($withprefix){
$name = get_string('block').': ';
}
$name .= $blockobject->title;
}
}
return $name;
}
/**
* Returns the most relevant URL for this context.
*
* @return moodle_url
*/
public function get_url() {
$parentcontexts = $this->get_parent_context();
return $parentcontexts->get_url();
}
/**
* Returns array of relevant context capability records.
*
* @return array
*/
public function get_capabilities() {
global $DB;
$sort = 'ORDER BY contextlevel,component,name'; // To group them sensibly for display
$params = array();
$bi = $DB->get_record('block_instances', array('id' => $this->_instanceid));
$extra = '';
$extracaps = block_method_result($bi->blockname, 'get_extra_capabilities');
if ($extracaps) {
list($extra, $params) = $DB->get_in_or_equal($extracaps, SQL_PARAMS_NAMED, 'cap');
$extra = "OR name $extra";
}
$sql = "SELECT *
FROM {capabilities}
WHERE (contextlevel = ".CONTEXT_BLOCK."
AND component = :component)
$extra";
$params['component'] = 'block_' . $bi->blockname;
return $DB->get_records_sql($sql.' '.$sort, $params);
}
/**
* Is this context part of any course? If yes return course context.
*
* @param bool $strict true means throw exception if not found, false means return false if not found
* @return context_course context of the enclosing course, null if not found or exception
*/
public function get_course_context($strict = true) {
$parentcontext = $this->get_parent_context();
return $parentcontext->get_course_context($strict);
}
/**
* Returns block context instance.
*
* @static
* @param int $blockinstanceid id from {block_instances} table.
* @param int $strictness
* @return context_block context instance
*/
public static function instance($blockinstanceid, $strictness = MUST_EXIST) {
global $DB;
if ($context = context::cache_get(CONTEXT_BLOCK, $blockinstanceid)) {
return $context;
}
if (!$record = $DB->get_record('context', array('contextlevel' => CONTEXT_BLOCK, 'instanceid' => $blockinstanceid))) {
if ($bi = $DB->get_record('block_instances', array('id' => $blockinstanceid), 'id,parentcontextid', $strictness)) {
$parentcontext = context::instance_by_id($bi->parentcontextid);
$record = context::insert_context_record(CONTEXT_BLOCK, $bi->id, $parentcontext->path);
}
}
if ($record) {
$context = new context_block($record);
context::cache_add($context);
return $context;
}
return false;
}
/**
* Block do not have child contexts...
* @return array
*/
public function get_child_contexts() {
return array();
}
/**
* Create missing context instances at block context level
* @static
*/
protected static function create_level_instances() {
global $DB;
$sql = "SELECT ".CONTEXT_BLOCK.", bi.id
FROM {block_instances} bi
WHERE NOT EXISTS (SELECT 'x'
FROM {context} cx
WHERE bi.id = cx.instanceid AND cx.contextlevel=".CONTEXT_BLOCK.")";
$contextdata = $DB->get_recordset_sql($sql);
foreach ($contextdata as $context) {
context::insert_context_record(CONTEXT_BLOCK, $context->id, null);
}
$contextdata->close();
}
/**
* Returns sql necessary for purging of stale context instances.
*
* @static
* @return string cleanup SQL
*/
protected static function get_cleanup_sql() {
$sql = "
SELECT c.*
FROM {context} c
LEFT OUTER JOIN {block_instances} bi ON c.instanceid = bi.id
WHERE bi.id IS NULL AND c.contextlevel = ".CONTEXT_BLOCK."
";
return $sql;
}
/**
* Rebuild context paths and depths at block context level.
*
* @static
* @param bool $force
*/
protected static function build_paths($force) {
global $DB;
if ($force or $DB->record_exists_select('context', "contextlevel = ".CONTEXT_BLOCK." AND (depth = 0 OR path IS NULL)")) {
if ($force) {
$ctxemptyclause = '';
} else {
$ctxemptyclause = "AND (ctx.path IS NULL OR ctx.depth = 0)";
}
// pctx.path IS NOT NULL prevents fatal problems with broken block instances that point to invalid context parent
$sql = "INSERT INTO {context_temp} (id, path, depth, locked)
SELECT ctx.id, ".$DB->sql_concat('pctx.path', "'/'", 'ctx.id').", pctx.depth+1, ctx.locked
FROM {context} ctx
JOIN {block_instances} bi ON (bi.id = ctx.instanceid AND ctx.contextlevel = ".CONTEXT_BLOCK.")
JOIN {context} pctx ON (pctx.id = bi.parentcontextid)
WHERE (pctx.path IS NOT NULL AND pctx.depth > 0)
$ctxemptyclause";
$trans = $DB->start_delegated_transaction();
$DB->delete_records('context_temp');
$DB->execute($sql);
context::merge_context_temp_table();
$DB->delete_records('context_temp');
$trans->allow_commit();
}
}
}
// ============== DEPRECATED FUNCTIONS ==========================================
// Old context related functions were deprecated in 2.0, it is recommended
// to use context classes in new code. Old function can be used when
// creating patches that are supposed to be backported to older stable branches.
// These deprecated functions will not be removed in near future,
// before removing devs will be warned with a debugging message first,
// then we will add error message and only after that we can remove the functions
// completely.
/**
* Runs get_records select on context table and returns the result
* Does get_records_select on the context table, and returns the results ordered
* by contextlevel, and then the natural sort order within each level.
* for the purpose of $select, you need to know that the context table has been
* aliased to ctx, so for example, you can call get_sorted_contexts('ctx.depth = 3');
*
* @param string $select the contents of the WHERE clause. Remember to do ctx.fieldname.
* @param array $params any parameters required by $select.
* @return array the requested context records.
*/
function get_sorted_contexts($select, $params = array()) {
//TODO: we should probably rewrite all the code that is using this thing, the trouble is we MUST NOT modify the context instances...
global $DB;
if ($select) {
$select = 'WHERE ' . $select;
}
return $DB->get_records_sql("
SELECT ctx.*
FROM {context} ctx
LEFT JOIN {user} u ON ctx.contextlevel = " . CONTEXT_USER . " AND u.id = ctx.instanceid
LEFT JOIN {course_categories} cat ON ctx.contextlevel = " . CONTEXT_COURSECAT . " AND cat.id = ctx.instanceid
LEFT JOIN {course} c ON ctx.contextlevel = " . CONTEXT_COURSE . " AND c.id = ctx.instanceid
LEFT JOIN {course_modules} cm ON ctx.contextlevel = " . CONTEXT_MODULE . " AND cm.id = ctx.instanceid
LEFT JOIN {block_instances} bi ON ctx.contextlevel = " . CONTEXT_BLOCK . " AND bi.id = ctx.instanceid
$select
ORDER BY ctx.contextlevel, bi.defaultregion, COALESCE(cat.sortorder, c.sortorder, cm.section, bi.defaultweight), u.lastname, u.firstname, cm.id
", $params);
}
/**
* Given context and array of users, returns array of users whose enrolment status is suspended,
* or enrolment has expired or has not started. Also removes those users from the given array
*
* @param context $context context in which suspended users should be extracted.
* @param array $users list of users.
* @param array $ignoreusers array of user ids to ignore, e.g. guest
* @return array list of suspended users.
*/
function extract_suspended_users($context, &$users, $ignoreusers=array()) {
global $DB;
// Get active enrolled users.
list($sql, $params) = get_enrolled_sql($context, null, null, true);
$activeusers = $DB->get_records_sql($sql, $params);
// Move suspended users to a separate array & remove from the initial one.
$susers = array();
if (sizeof($activeusers)) {
foreach ($users as $userid => $user) {
if (!array_key_exists($userid, $activeusers) && !in_array($userid, $ignoreusers)) {
$susers[$userid] = $user;
unset($users[$userid]);
}
}
}
return $susers;
}
/**
* Given context and array of users, returns array of user ids whose enrolment status is suspended,
* or enrolment has expired or not started.
*
* @param context $context context in which user enrolment is checked.
* @param bool $usecache Enable or disable (default) the request cache
* @return array list of suspended user id's.
*/
function get_suspended_userids(context $context, $usecache = false) {
global $DB;
if ($usecache) {
$cache = cache::make('core', 'suspended_userids');
$susers = $cache->get($context->id);
if ($susers !== false) {
return $susers;
}
}
$coursecontext = $context->get_course_context();
$susers = array();
// Front page users are always enrolled, so suspended list is empty.
if ($coursecontext->instanceid != SITEID) {
list($sql, $params) = get_enrolled_sql($context, null, null, false, true);
$susers = $DB->get_fieldset_sql($sql, $params);
$susers = array_combine($susers, $susers);
}
// Cache results for the remainder of this request.
if ($usecache) {
$cache->set($context->id, $susers);
}
return $susers;
}
/**
* Gets sql for finding users with capability in the given context
*
* @param context $context
* @param string|array $capability Capability name or array of names.
* If an array is provided then this is the equivalent of a logical 'OR',
* i.e. the user needs to have one of these capabilities.
* @return array($sql, $params)
*/
function get_with_capability_sql(context $context, $capability) {
static $i = 0;
$i++;
$prefix = 'cu' . $i . '_';
$capjoin = get_with_capability_join($context, $capability, $prefix . 'u.id');
$sql = "SELECT DISTINCT {$prefix}u.id
FROM {user} {$prefix}u
$capjoin->joins
WHERE {$prefix}u.deleted = 0 AND $capjoin->wheres";
return array($sql, $capjoin->params);
}