Current Path : C:/Users/Mahmood/Desktop/moodle8/files/classes/ |
Current File : C:/Users/Mahmood/Desktop/moodle8/files/classes/converter.php |
<?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/>. /** * Class for converting files between different file formats using unoconv. * * @package core_files * @copyright 2017 Damyon Wiese * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later */ namespace core_files; defined('MOODLE_INTERNAL') || die(); use stored_file; /** * Class for converting files between different formats using unoconv. * * @package core_files * @copyright 2017 Damyon Wiese * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later */ class converter { /** * Get a list of enabled plugins and classes. * * @return array List of enabled plugins */ protected function get_enabled_plugins() { $plugins = \core\plugininfo\fileconverter::get_enabled_plugins(); $pluginclasses = []; foreach ($plugins as $plugin) { $pluginclasses[$plugin] = \core\plugininfo\fileconverter::get_classname($plugin); } return $pluginclasses; } /** * Return the file_storage API. * * This allows for mocking of the file_storage API. * * @return \file_storage */ protected function get_file_storage() { return get_file_storage(); } /** * Start the conversion for a stored_file into a new format. * * @param stored_file $file The file to convert * @param string $format The desired target file format (file extension) * @param boolean $forcerefresh If true, the file will be converted every time (not cached). * @return conversion conversion object */ public function start_conversion(stored_file $file, $format, $forcerefresh = false) { $conversions = conversion::get_conversions_for_file($file, $format); if ($forcerefresh || count($conversions) > 1) { while ($conversion = array_shift($conversions)) { if ($conversion->get('id')) { $conversion->delete(); } } } if (empty($conversions)) { $conversion = new conversion(0, (object) [ 'sourcefileid' => $file->get_id(), 'targetformat' => $format, ]); $conversion->create(); } else { $conversion = array_shift($conversions); } if ($conversion->get('status') !== conversion::STATUS_COMPLETE) { $this->poll_conversion($conversion); } return $conversion; } /** * Poll for updates to the supplied conversion. * * @param conversion $conversion The conversion in progress * @return $this */ public function poll_conversion(conversion $conversion) { $format = $conversion->get('targetformat'); $file = $conversion->get_sourcefile(); if ($conversion->get('status') == conversion::STATUS_IN_PROGRESS) { // The current conversion is in progress. // Check for updates. if ($instance = $conversion->get_converter_instance()) { $instance->poll_conversion_status($conversion); } else { // Unable to fetch the converter instance. // Reset the status back to PENDING so that it may be picked up again. $conversion->set('status', conversion::STATUS_PENDING); } $conversion->update(); } // Refresh the status. $status = $conversion->get('status'); if ($status === conversion::STATUS_PENDING || $status === conversion::STATUS_FAILED) { // The current status is either pending or failed. // Attempt to pick up a new converter and convert the document. $from = pathinfo($file->get_filename(), PATHINFO_EXTENSION); $converters = $this->get_document_converter_classes($from, $format); $currentconverter = $this->get_next_converter($converters, $conversion->get('converter')); if (!$currentconverter) { // No more converters available. $conversion->set('status', conversion::STATUS_FAILED); $conversion->update(); return $this; } do { $conversion ->set('converter', $currentconverter) ->set('status', conversion::STATUS_IN_PROGRESS) ->update(); $instance = $conversion->get_converter_instance(); $instance->start_document_conversion($conversion); $failed = $conversion->get('status') === conversion::STATUS_FAILED; $currentconverter = $this->get_next_converter($converters, $currentconverter); } while ($failed && $currentconverter); $conversion->update(); } return $this; } /** * Fetch the next converter to try. * * @param array $converters The list of converters to try * @param string|null $currentconverter The converter currently in use * @return string|false Name of next converter if present */ protected function get_next_converter($converters, $currentconverter = null) { if ($currentconverter) { $keys = array_keys($converters, $currentconverter); $key = $keys[0]; if (isset($converters[$key + 1])) { return $converters[$key + 1]; } else { return false; } } else if (!empty($converters)) { return $converters[0]; } else { return false; } } /** * Fetch the class for the preferred document converter. * * @param string $from The source target file (file extension) * @param string $to The desired target file format (file extension) * @return string The class for document conversion */ protected function get_document_converter_classes($from, $to) { $classes = []; $converters = $this->get_enabled_plugins(); foreach ($converters as $plugin => $classname) { if (!class_exists($classname)) { continue; } if (!$classname::are_requirements_met()) { continue; } if ($classname::supports($from, $to)) { $classes[] = $classname; } } return $classes; } /** * Check whether document conversion is supported for this file and target format. * * @param stored_file $file The file to convert * @param string $to The desired target file format (file extension) * @return bool Whether the target type can be converted */ public function can_convert_storedfile_to(stored_file $file, $to) { if ($file->is_directory()) { // Directories cannot be converted. return false; } if (!$file->get_filesize()) { // Empty files cannot be converted. return false; } $from = pathinfo($file->get_filename(), PATHINFO_EXTENSION); if (!$from) { // No file extension could be found. Unable to determine converter. return false; } return $this->can_convert_format_to($from, $to); } /** * Check whether document conversion is supported for this file and target format. * * @param string $from The source target file (file extension) * @param string $to The desired target file format (file extension) * @return bool Whether the target type can be converted */ public function can_convert_format_to($from, $to) { return !empty($this->get_document_converter_classes($from, $to)); } }