Proyectos de Subversion Moodle

<?php

// This file is part of Moodle - https://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 <https://www.gnu.org/licenses/>.

namespace core\context;

use core\context;

use stdClass;

use coding_exception, moodle_url;

/**

 * Course context class

 *

 * @package   core_access

 * @category  access

 * @copyright Petr Skoda

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

 * @since     Moodle 4.2

 */

class course extends context {

    /** @var int numeric context level value matching legacy CONTEXT_COURSE */

    public const LEVEL = 50;

    /**

     * Please use \core\context\course::instance($courseid) if you need the instance of context.

     * Alternatively if you know only the context id use \core\context::instance_by_id($contextid)

     *

     * @param stdClass $record

     */

    protected function __construct(stdClass $record) {

        parent::__construct($record);

        if ($record->contextlevel != self::LEVEL) {

            throw new coding_exception('Invalid $record->contextlevel in core\context\course constructor.');

        }

    }

    /**

     * Returns short context name.

     *

     * @since Moodle 4.2

     *

     * @return string

     */

    public static function get_short_name(): string {

        return 'course';

    }

    /**

     * Returns human readable context level name.

     *

     * @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.

     * @param bool $escape Whether the returned category name is to be HTML escaped or not.

     * @return string the human readable context name.

     */

    public function get_context_name($withprefix = true, $short = false, $escape = true) {

        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) {

                    if (!$escape) {

                        $name .= format_string($course->shortname, true, array('context' => $this, 'escape' => false));

                    } else {

                        $name .= format_string($course->shortname, true, array('context' => $this));

                    }

                } else {

                    if (!$escape) {

                        $name .= format_string(get_course_display_name_for_list($course), true, array('context' => $this,

                            'escape' => false));

                    } else {

                        $name .= format_string(get_course_display_name_for_list($course), true, array('context' => $this));

                    }

                }

            }

        }

        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 context instance database name.

     *

     * @return string|null table name for all levels except system.

     */

    protected static function get_instance_table(): ?string {

        return 'course';

    }

    /**

     * Returns list of columns that can be used from behat

     * to look up context by reference.

     *

     * @return array list of column names from instance table

     */

    protected static function get_behat_reference_columns(): array {

        return ['shortname'];

    }

    /**

     * Returns list of all role archetypes that are compatible

     * with role assignments in context level.

     * @since Moodle 4.2

     *

     * @return int[]

     */

    protected static function get_compatible_role_archetypes(): array {

        return ['manager', 'editingteacher', 'teacher', 'student'];

    }

    /**

     * Returns list of all possible parent context levels.

     * @since Moodle 4.2

     *

     * @return int[]

     */

    public static function get_possible_parent_levels(): array {

        return [coursecat::LEVEL];

    }

    /**

     * Returns array of relevant context capability records.

     *

     * @param string $sort

     * @return array

     */

    public function get_capabilities(string $sort = self::DEFAULT_CAPABILITY_SORT) {

        global $DB;

        $levels = \core\context_helper::get_child_levels(self::LEVEL);

        $levels[] = self::LEVEL;

        return $DB->get_records_list('capabilities', 'contextlevel', $levels, $sort);

    }

    /**

     * 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 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.

     *

     * @param int $courseid id from {course} table

     * @param int $strictness

     * @return course|false context instance

     */

    public static function instance($courseid, $strictness = MUST_EXIST) {

        global $DB;

        if ($context = context::cache_get(self::LEVEL, $courseid)) {

            return $context;

        }

        if (!$record = $DB->get_record('context', array('contextlevel' => self::LEVEL, 'instanceid' => $courseid))) {

            if ($course = $DB->get_record('course', array('id' => $courseid), 'id,category', $strictness)) {

                if ($course->category) {

                    $parentcontext = coursecat::instance($course->category);

                    $record = context::insert_context_record(self::LEVEL, $course->id, $parentcontext->path);

                } else {

                    $record = context::insert_context_record(self::LEVEL, $course->id, '/'.SYSCONTEXTID, 0);

                }

            }

        }

        if ($record) {

            $context = new course($record);

            context::cache_add($context);

            return $context;

        }

        return false;

    }

    /**

     * Create missing context instances at course context level

     */

    protected static function create_level_instances() {

        global $DB;

        $sql = "SELECT ".self::LEVEL.", c.id

                  FROM {course} c

                 WHERE NOT EXISTS (SELECT 'x'

                                     FROM {context} cx

                                    WHERE c.id = cx.instanceid AND cx.contextlevel=".self::LEVEL.")";

        $contextdata = $DB->get_recordset_sql($sql);

        foreach ($contextdata as $context) {

            context::insert_context_record(self::LEVEL, $context->id, null);

        }

        $contextdata->close();

    }

    /**

     * Returns sql necessary for purging of stale context instances.

     *

     * @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 = ".self::LEVEL."

               ";

        return $sql;

    }

    /**

     * Rebuild context paths and depths at course context level.

     *

     * @param bool $force

     */

    protected static function build_paths($force) {

        global $DB;

        if ($force || $DB->record_exists_select('context', "contextlevel = ".self::LEVEL." 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 = ".self::LEVEL."

                           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 = ".self::LEVEL." AND c.category <> 0)

                      JOIN {context} pctx ON (pctx.instanceid = c.category AND pctx.contextlevel = ".coursecat::LEVEL.")

                     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();

        }

    }

}