Proyectos de Subversion Moodle

<?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/>.

/**

 * Contains event class for providing the related objects when exporting a list of calendar events.

 *

 * @package   core_calendar

 * @copyright 2017 Ryan Wyllie <ryan@moodle.com>

 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

namespace core_calendar\external;

defined('MOODLE_INTERNAL') || die();

use \core_calendar\local\event\entities\event_interface;

/**

 * Class to providing the related objects when exporting a list of calendar events.

 *

 * This class is only meant for use with exporters. It attempts to bulk load

 * the related objects for a list of events and cache them to avoid having

 * to query the database when exporting each individual event.

 *

 * @package   core_calendar

 * @copyright 2017 Ryan Wyllie <ryan@moodle.com>

 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

class events_related_objects_cache {

    /**

     * @var array $events The events for which we need related objects.

     */

    protected $events;

    /**

     * @var array $courses The related courses.

     */

    protected $courses = null;

    /**

     * @var array $groups The related groups.

     */

    protected $groups = null;

    /**

     * @var array $coursemodules The related course modules.

     */

    protected $coursemodules = [];

    /**

     * @var array $moduleinstances The related module instances.

     */

    protected $moduleinstances = null;

    /**

     * Constructor.

     *

     * @param array $events Array of event_interface events

     * @param array $courses Array of courses to populate the cache with

     */

    public function __construct(array $events, array $courses = null) {

        $this->events = $events;

        if (!is_null($courses)) {

            $this->courses = [];

            foreach ($courses as $course) {

                $this->courses[$course->id] = $course;

            }

        }

    }

    /**

     * Get the related course object for a given event.

     *

     * @param event_interface $event The event object.

     * @return \stdClass|null

     */

    public function get_course(event_interface $event) {

        if (is_null($this->courses)) {

            $this->load_courses();

        }

        if ($course = $event->get_course()) {

            $courseid = $course->get('id');

            return isset($this->courses[$courseid]) ? $this->courses[$courseid] : null;

        } else {

            return null;

        }

    }

    /**

     * Get the related context for a given event.

     *

     * @param event_interface $event The event object.

     * @return \context|null

     */

    public function get_context(event_interface $event) {

        global $USER;

        $categoryid = $event->get_category() ? $event->get_category()->get('id') : null;

        $courseid = $event->get_course() ? $event->get_course()->get('id') : null;

        $groupid = $event->get_group() ? $event->get_group()->get('id') : null;

        $userid = $event->get_user() ? $event->get_user()->get('id') : null;

        $moduleid = $event->get_course_module() ? $event->get_course_module()->get('id') : null;

        if (!empty($categoryid)) {

            return \context_coursecat::instance($categoryid);

        } else if (!empty($courseid)) {

            return \context_course::instance($event->get_course()->get('id'));

        } else if (!empty($groupid)) {

            $group = $this->get_group($event);

            return \context_course::instance($group->courseid);

        } else if (!empty($userid) && $userid == $USER->id) {

            return \context_user::instance($userid);

        } else if (!empty($userid) && $userid != $USER->id && $moduleid && $moduleid > 0) {

            $cm = $this->get_course_module($event);

            return \context_course::instance($cm->course);

        } else {

            return \context_user::instance($userid);

        }

    }

    /**

     * Get the related group object for a given event.

     *

     * @param event_interface $event The event object.

     * @return \stdClass|null

     */

    public function get_group(event_interface $event) {

        if (is_null($this->groups)) {

            $this->load_groups();

        }

        if ($group = $event->get_group()) {

            $groupid = $group->get('id');

            return isset($this->groups[$groupid]) ? $this->groups[$groupid] : null;

        } else {

            return null;

        }

    }

    /**

     * Get the related course module for a given event.

     *

     * @param event_interface $event The event object.

     * @return \stdClass|null

     */

    public function get_course_module(event_interface $event) {

        if (!$event->get_course_module()) {

            return null;

        }

        $id = $event->get_course_module()->get('id');

        $name = $event->get_course_module()->get('modname');

        $key = $name . '_' . $id;

        if (!isset($this->coursemodules[$key])) {

            $this->coursemodules[$key] = get_coursemodule_from_instance($name, $id, 0, false, MUST_EXIST);

        }

        return $this->coursemodules[$key];

    }

    /**

     * Get the related module instance for a given event.

     *

     * @param event_interface $event The event object.

     * @return \stdClass|null

     */

    public function get_module_instance(event_interface $event) {

        if (!$event->get_course_module()) {

            return null;

        }

        if (is_null($this->moduleinstances)) {

            $this->load_module_instances();

        }

        $id = $event->get_course_module()->get('instance');

        $name = $event->get_course_module()->get('modname');

        if (isset($this->moduleinstances[$name])) {

            if (isset($this->moduleinstances[$name][$id])) {

                return $this->moduleinstances[$name][$id];

            }

        }

        return null;

    }

    /**

     * Load the list of all of the distinct courses required for the

     * list of provided events and save the result in memory.

     */

    protected function load_courses() {

        global $DB;

        $courseids = [];

        foreach ($this->events as $event) {

            if ($course = $event->get_course()) {

                $id = $course->get('id');

                $courseids[$id] = true;

            }

        }

        if (empty($courseids)) {

            $this->courses = [];

            return;

        }

        list($idsql, $params) = $DB->get_in_or_equal(array_keys($courseids));

        $sql = "SELECT * FROM {course} WHERE id {$idsql}";

        $this->courses = $DB->get_records_sql($sql, $params);

    }

    /**

     * Load the list of all of the distinct groups required for the

     * list of provided events and save the result in memory.

     */

    protected function load_groups() {

        global $DB;

        $groupids = [];

        foreach ($this->events as $event) {

            if ($group = $event->get_group()) {

                $id = $group->get('id');

                $groupids[$id] = true;

            }

        }

        if (empty($groupids)) {

            $this->groups = [];

            return;

        }

        list($idsql, $params) = $DB->get_in_or_equal(array_keys($groupids));

        $sql = "SELECT * FROM {groups} WHERE id {$idsql}";

        $this->groups = $DB->get_records_sql($sql, $params);

    }

    /**

     * Load the list of all of the distinct module instances required for the

     * list of provided events and save the result in memory.

     */

    protected function load_module_instances() {

        global $DB;

        $this->moduleinstances = [];

        $modulestoload = [];

        foreach ($this->events as $event) {

            if ($module = $event->get_course_module()) {

                $id = $module->get('instance');

                $name = $module->get('modname');

                $ids = isset($modulestoload[$name]) ? $modulestoload[$name] : [];

                $ids[$id] = true;

                $modulestoload[$name] = $ids;

            }

        }

        if (empty($modulestoload)) {

            return;

        }

        foreach ($modulestoload as $modulename => $ids) {

            list($idsql, $params) = $DB->get_in_or_equal(array_keys($ids));

            $sql = "SELECT * FROM {" . $modulename . "} WHERE id {$idsql}";

            $this->moduleinstances[$modulename] = $DB->get_records_sql($sql, $params);

        }

    }

}