Your IP : 192.168.165.1
<?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/>.
/**
* Analysers base class.
*
* @package core_analytics
* @copyright 2016 David Monllao {@link http://www.davidmonllao.com}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
namespace core_analytics\local\analyser;
defined('MOODLE_INTERNAL') || die();
/**
* Analysers base class.
*
* @package core_analytics
* @copyright 2016 David Monllao {@link http://www.davidmonllao.com}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
abstract class base {
/**
* @var int
*/
protected $modelid;
/**
* The model target.
*
* @var \core_analytics\local\target\base
*/
protected $target;
/**
* The model indicators.
*
* @var \core_analytics\local\indicator\base[]
*/
protected $indicators;
/**
* Time splitting methods to use.
*
* Multiple time splitting methods during evaluation and 1 single
* time splitting method once the model is enabled.
*
* @var \core_analytics\local\time_splitting\base[]
*/
protected $timesplittings;
/**
* Execution options.
*
* @var array
*/
protected $options;
/**
* Simple log array.
*
* @var string[]
*/
protected $log;
/**
* Constructor method.
*
* @param int $modelid
* @param \core_analytics\local\target\base $target
* @param \core_analytics\local\indicator\base[] $indicators
* @param \core_analytics\local\time_splitting\base[] $timesplittings
* @param array $options
* @return void
*/
public function __construct($modelid, \core_analytics\local\target\base $target, $indicators, $timesplittings, $options) {
$this->modelid = $modelid;
$this->target = $target;
$this->indicators = $indicators;
$this->timesplittings = $timesplittings;
if (empty($options['evaluation'])) {
$options['evaluation'] = false;
}
$this->options = $options;
// Checks if the analyser satisfies the indicators requirements.
$this->check_indicators_requirements();
$this->log = array();
}
/**
* Returns the list of analysable elements available on the site.
*
* \core_analytics\local\analyser\by_course and \core_analytics\local\analyser\sitewide are implementing
* this method returning site courses (by_course) and the whole system (sitewide) as analysables.
*
* @todo MDL-65284 This will be removed in Moodle 4.1
* @deprecated
* @see get_analysables_iterator
* @throws \coding_exception
* @return \core_analytics\analysable[] Array of analysable elements using the analysable id as array key.
*/
public function get_analysables() {
// This function should only be called from get_analysables_iterator and we keep it here until Moodle 4.1
// for backwards compatibility.
throw new \coding_exception('This method is deprecated in favour of get_analysables_iterator.');
}
/**
* Returns the list of analysable elements available on the site.
*
* A relatively complex SQL query should be set so that we take into account which analysable elements
* have already been processed and the order in which they have been processed. Helper methods are available
* to ease to implementation of get_analysables_iterator: get_iterator_sql and order_sql.
*
* @param string|null $action 'prediction', 'training' or null if no specific action needed.
* @param \context[] $contexts Only analysables that depend on the provided contexts. All analysables in the system if empty.
* @return \Iterator
*/
public function get_analysables_iterator(?string $action = null, array $contexts = []) {
debugging('Please overwrite get_analysables_iterator with your own implementation, we only keep this default
implementation for backwards compatibility purposes with get_analysables(). note that $action param will
be ignored so the analysable elements will be processed using get_analysables order, regardless of the
last time they were processed.');
return new \ArrayIterator($this->get_analysables());
}
/**
* This function returns this analysable list of samples.
*
* @param \core_analytics\analysable $analysable
* @return array array[0] = int[] (sampleids) and array[1] = array (samplesdata)
*/
abstract public function get_all_samples(\core_analytics\analysable $analysable);
/**
* This function returns the samples data from a list of sample ids.
*
* @param int[] $sampleids
* @return array array[0] = int[] (sampleids) and array[1] = array (samplesdata)
*/
abstract public function get_samples($sampleids);
/**
* Returns the analysable of a sample.
*
* @param int $sampleid
* @return \core_analytics\analysable
*/
abstract public function get_sample_analysable($sampleid);
/**
* Returns the sample's origin in moodle database.
*
* @return string
*/
abstract public function get_samples_origin();
/**
* Returns the context of a sample.
*
* moodle/analytics:listinsights will be required at this level to access the sample predictions.
*
* @param int $sampleid
* @return \context
*/
abstract public function sample_access_context($sampleid);
/**
* Describes a sample with a description summary and a \renderable (an image for example)
*
* @param int $sampleid
* @param int $contextid
* @param array $sampledata
* @return array array(string, \renderable)
*/
abstract public function sample_description($sampleid, $contextid, $sampledata);
/**
* Model id getter.
* @return int
*/
public function get_modelid(): int {
return $this->modelid;
}
/**
* Options getter.
* @return array
*/
public function get_options(): array {
return $this->options;
}
/**
* Returns the analysed target.
*
* @return \core_analytics\local\target\base
*/
public function get_target(): \core_analytics\local\target\base {
return $this->target;
}
/**
* Getter for time splittings.
*
* @return \core_analytics\local\time_splitting\base
*/
public function get_timesplittings(): array {
return $this->timesplittings;
}
/**
* Getter for indicators.
*
* @return \core_analytics\local\indicator\base
*/
public function get_indicators(): array {
return $this->indicators;
}
/**
* Instantiate the indicators.
*
* @return \core_analytics\local\indicator\base[]
*/
public function instantiate_indicators() {
foreach ($this->indicators as $key => $indicator) {
$this->indicators[$key] = call_user_func(array($indicator, 'instance'));
}
// Free memory ASAP.
gc_collect_cycles();
gc_mem_caches();
return $this->indicators;
}
/**
* Samples data this analyser provides.
*
* @return string[]
*/
protected function provided_sample_data() {
return array($this->get_samples_origin());
}
/**
* Returns labelled data (training and evaluation).
*
* @param \context[] $contexts Restrict the analysis to these contexts. No context restrictions if null.
* @return \stored_file[]
*/
public function get_labelled_data(array $contexts = []) {
// Delegates all processing to the analysis.
$result = new \core_analytics\local\analysis\result_file($this->get_modelid(), true, $this->get_options());
$analysis = new \core_analytics\analysis($this, true, $result);
$analysis->run($contexts);
return $result->get();
}
/**
* Returns unlabelled data (prediction).
*
* @param \context[] $contexts Restrict the analysis to these contexts. No context restrictions if null.
* @return \stored_file[]
*/
public function get_unlabelled_data(array $contexts = []) {
// Delegates all processing to the analysis.
$result = new \core_analytics\local\analysis\result_file($this->get_modelid(), false, $this->get_options());
$analysis = new \core_analytics\analysis($this, false, $result);
$analysis->run($contexts);
return $result->get();
}
/**
* Returns indicator calculations as an array.
*
* @param \context[] $contexts Restrict the analysis to these contexts. No context restrictions if null.
* @return array
*/
public function get_static_data(array $contexts = []) {
// Delegates all processing to the analysis.
$result = new \core_analytics\local\analysis\result_array($this->get_modelid(), false, $this->get_options());
$analysis = new \core_analytics\analysis($this, false, $result);
$analysis->run($contexts);
return $result->get();
}
/**
* Checks if the analyser satisfies all the model indicators requirements.
*
* @throws \core_analytics\requirements_exception
* @return void
*/
protected function check_indicators_requirements() {
foreach ($this->indicators as $indicator) {
$missingrequired = $this->check_indicator_requirements($indicator);
if ($missingrequired !== true) {
throw new \core_analytics\requirements_exception(get_class($indicator) . ' indicator requires ' .
json_encode($missingrequired) . ' sample data which is not provided by ' . get_class($this));
}
}
}
/**
* Checks that this analyser satisfies the provided indicator requirements.
*
* @param \core_analytics\local\indicator\base $indicator
* @return true|string[] True if all good, missing requirements list otherwise
*/
public function check_indicator_requirements(\core_analytics\local\indicator\base $indicator) {
$providedsampledata = $this->provided_sample_data();
$requiredsampledata = $indicator::required_sample_data();
if (empty($requiredsampledata)) {
// The indicator does not need any sample data.
return true;
}
$missingrequired = array_diff($requiredsampledata, $providedsampledata);
if (empty($missingrequired)) {
return true;
}
return $missingrequired;
}
/**
* Adds a register to the analysis log.
*
* @param string $string
* @return void
*/
public function add_log($string) {
$this->log[] = $string;
}
/**
* Returns the analysis logs.
*
* @return string[]
*/
public function get_logs() {
return $this->log;
}
/**
* Whether the plugin needs user data clearing or not.
*
* This is related to privacy. Override this method if your analyser samples have any relation
* to the 'user' database entity. We need to clean the site from all user-related data if a user
* request their data to be deleted from the system. A static::provided_sample_data returning 'user'
* is an indicator that you should be returning true.
*
* @return bool
*/
public function processes_user_data() {
return false;
}
/**
* SQL JOIN from a sample to users table.
*
* This function should be defined if static::processes_user_data returns true and it is related to analytics API
* privacy API implementation. It allows the analytics API to identify data associated to users that needs to be
* deleted or exported.
*
* This function receives the alias of a table with a 'sampleid' field and it should return a SQL join
* with static::get_samples_origin and with 'user' table. Note that:
* - The function caller expects the returned 'user' table to be aliased as 'u' (defacto standard in moodle).
* - You can join with other tables if your samples origin table does not contain a 'userid' field (if that would be
* a requirement this solution would be automated for you) you can't though use the following
* aliases: 'ap', 'apa', 'aic' and 'am'.
*
* Some examples:
*
* static::get_samples_origin() === 'user':
* JOIN {user} u ON {$sampletablealias}.sampleid = u.id
*
* static::get_samples_origin() === 'role_assignments':
* JOIN {role_assignments} ra ON {$sampletablealias}.sampleid = ra.userid JOIN {user} u ON u.id = ra.userid
*
* static::get_samples_origin() === 'user_enrolments':
* JOIN {user_enrolments} ue ON {$sampletablealias}.sampleid = ue.userid JOIN {user} u ON u.id = ue.userid
*
* @throws \coding_exception
* @param string $sampletablealias The alias of the table with a sampleid field that will join with this SQL string
* @return string
*/
public function join_sample_user($sampletablealias) {
throw new \coding_exception('This method should be implemented if static::processes_user_data returns true.');
}
/**
* Do this analyser's analysables have 1 single sample each?
*
* Overwrite and return true if your analysables only have
* one sample. The insights generated by models using this
* analyser will then include the suggested actions in the
* notification.
*
* @return bool
*/
public static function one_sample_per_analysable() {
return false;
}
/**
* Returns an array of context levels that can be used to restrict the contexts used during analysis.
*
* The contexts provided to self::get_analysables_iterator will match these contextlevels.
*
* @return array Array of context levels or an empty array if context restriction is not supported.
*/
public static function context_restriction_support(): array {
return [];
}
/**
* Returns the possible contexts used by the analyser.
*
* This method uses separate logic for each context level because to iterate through
* the list of contexts calling get_context_name for each of them would be expensive
* in performance terms.
*
* This generic implementation returns all the contexts in the site for the provided context level.
* Overwrite it for specific restrictions in your analyser.
*
* @param string|null $query Context name filter.
* @return int[]
*/
public static function potential_context_restrictions(string $query = null) {
return \core_analytics\manager::get_potential_context_restrictions(static::context_restriction_support(), $query);
}
/**
* Get the sql of a default implementation of the iterator.
*
* This method only works for analysers that return analysable elements which ids map to a context instance ids.
*
* @param string $tablename The name of the table
* @param int $contextlevel The context level of the analysable
* @param string|null $action
* @param string|null $tablealias The table alias
* @param \context[] $contexts Only analysables that depend on the provided contexts. All analysables if empty.
* @return array [0] => sql and [1] => params array
*/
protected function get_iterator_sql(string $tablename, int $contextlevel, ?string $action = null, ?string $tablealias = null,
array $contexts = []) {
global $DB;
if (!$tablealias) {
$tablealias = 'analysable';
}
$params = ['contextlevel' => $contextlevel, 'modelid' => $this->get_modelid()];
$select = $tablealias . '.*, ' . \context_helper::get_preload_record_columns_sql('ctx');
// We add the action filter on ON instead of on WHERE because otherwise records are not returned if there are existing
// records for another action or model.
$usedanalysablesjoin = ' LEFT JOIN {analytics_used_analysables} aua ON ' . $tablealias . '.id = aua.analysableid AND ' .
'(aua.modelid = :modelid OR aua.modelid IS NULL)';
if ($action) {
$usedanalysablesjoin .= " AND aua.action = :action";
$params = $params + ['action' => $action];
}
$sql = 'SELECT ' . $select . '
FROM {' . $tablename . '} ' . $tablealias . '
' . $usedanalysablesjoin . '
JOIN {context} ctx ON (ctx.contextlevel = :contextlevel AND ctx.instanceid = ' . $tablealias . '.id) ';
if (!$contexts) {
// Adding the 1 = 1 just to have the WHERE part so that all further conditions
// added by callers can be appended to $sql with and ' AND'.
$sql .= 'WHERE 1 = 1';
} else {
$contextsqls = [];
foreach ($contexts as $context) {
$paramkey1 = 'paramctxlike' . $context->id;
$paramkey2 = 'paramctxeq' . $context->id;
$contextsqls[] = $DB->sql_like('ctx.path', ':' . $paramkey1);
$contextsqls[] = 'ctx.path = :' . $paramkey2;
// This includes the context itself.
$params[$paramkey1] = $context->path . '/%';
$params[$paramkey2] = $context->path;
}
$sql .= 'WHERE (' . implode(' OR ', $contextsqls) . ')';
}
return [$sql, $params];
}
/**
* Returns the order by clause.
*
* @param string|null $fieldname The field name
* @param string $order 'ASC' or 'DESC'
* @param string|null $tablealias The table alias of the field
* @return string
*/
protected function order_sql(?string $fieldname = null, string $order = 'ASC', ?string $tablealias = null) {
if (!$tablealias) {
$tablealias = 'analysable';
}
if ($order != 'ASC' && $order != 'DESC') {
throw new \coding_exception('The order can only be ASC or DESC');
}
$ordersql = ' ORDER BY (CASE WHEN aua.timeanalysed IS NULL THEN 0 ELSE aua.timeanalysed END) ASC';
if ($fieldname) {
$ordersql .= ', ' . $tablealias . '.' . $fieldname .' ' . $order;
}
return $ordersql;
}
}