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/>.

/**

 * Utility class for browsing of module files.

 *

 * @package    core_files

 * @copyright  2008 Petr Skoda (http://skodak.org)

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

 */

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

/**

 * Represents a module context in the tree navigated by {@link file_browser}.

 *

 * @package    core_files

 * @copyright  2008 Petr Skoda (http://skodak.org)

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

 */

class file_info_context_module extends file_info {

    /** @var stdClass Course object */

    protected $course;

    /** @var cm_info Course module object */

    protected $cm;

    /** @var string Module name */

    protected $modname;

    /** @var array Available file areas */

    protected $areas;

    /** @var array caches the result of last call to get_non_empty_children() */

    protected $nonemptychildren;

    /**

     * Constructor

     *

     * @param file_browser $browser file browser instance

     * @param stdClass $context context object

     * @param stdClass $course course object

     * @param stdClass $cm course module object

     * @param string $modname module name

     */

    public function __construct($browser, $context, $course, $cm, $modname) {

        global $CFG;

        parent::__construct($browser, $context);

        $this->course  = $course;

        $this->cm      = cm_info::create($cm);

        $this->modname = $this->cm->modname;

        $this->nonemptychildren = null;

        if ($functionname = component_callback_exists('mod_'.$modname, 'get_file_areas')) {

            $cm = $this->cm->get_course_module_record();

            $this->areas = $functionname($course, $cm, $context);

        } else {

            $this->areas = array();

        }

        unset($this->areas['intro']); // hardcoded, ignore attempts to override it

    }

    /**

     * Return information about this specific context level

     *

     * @param string $component component

     * @param string $filearea file area

     * @param int $itemid item ID

     * @param string $filepath file path

     * @param string $filename file name

     * @return file_info|null

     */

    public function get_file_info($component, $filearea, $itemid, $filepath, $filename) {

        // try to emulate require_login() tests here

        if (!isloggedin()) {

            return null;

        }

        $coursecontext = $this->context->get_course_context(true);

        if (!$this->course->visible and !has_capability('moodle/course:viewhiddencourses', $coursecontext)) {

            return null;

        }

        if (!is_viewing($this->context) and !$this->browser->is_enrolled($this->course->id)) {

            // no peaking here if not enrolled or inspector

            return null;

        }

        if (!$this->cm->uservisible) {

            // activity hidden sorry

            return null;

        }

        if (empty($component)) {

            return $this;

        }

        if ($component == 'mod_'.$this->modname and $filearea === 'intro') {

            return $this->get_area_intro($itemid, $filepath, $filename);

        } else if ($component == 'backup' and $filearea === 'activity') {

            return $this->get_area_backup($itemid, $filepath, $filename);

        }

        if ($functionname = component_callback_exists('mod_'.$this->modname, 'get_file_info')) {

            $cm = $this->cm->get_course_module_record();

            return $functionname($this->browser, $this->areas, $this->course, $cm,

                $this->context, $filearea, $itemid, $filepath, $filename);

        }

        return null;

    }

    /**

     * Get a file from module intro area

     *

     * @param int $itemid item ID

     * @param string $filepath file path

     * @param string $filename file name

     * @return file_info|null

     */

    protected function get_area_intro($itemid, $filepath, $filename) {

        global $CFG;

        if (!plugin_supports('mod', $this->modname, FEATURE_MOD_INTRO, true) or !has_capability('moodle/course:managefiles', $this->context)) {

            return null;

        }

        $fs = get_file_storage();

        $filepath = is_null($filepath) ? '/' : $filepath;

        $filename = is_null($filename) ? '.' : $filename;

        if (!$storedfile = $fs->get_file($this->context->id, 'mod_'.$this->modname, 'intro', 0, $filepath, $filename)) {

            if ($filepath === '/' and $filename === '.') {

                $storedfile = new virtual_root_file($this->context->id, 'mod_'.$this->modname, 'intro', 0);

            } else {

                // not found

                return null;

            }

        }

        $urlbase = $CFG->wwwroot.'/pluginfile.php';

        return new file_info_stored($this->browser, $this->context, $storedfile, $urlbase, get_string('moduleintro'), false, true, true, false);

    }

    /**

     * Get a file from module backup area

     *

     * @param int $itemid item ID

     * @param string $filepath file path

     * @param string $filename file name

     * @return file_info|null

     */

    protected function get_area_backup($itemid, $filepath, $filename) {

        global $CFG;

        if (!has_capability('moodle/backup:backupactivity', $this->context)) {

            return null;

        }

        $fs = get_file_storage();

        $filepath = is_null($filepath) ? '/' : $filepath;

        $filename = is_null($filename) ? '.' : $filename;

        if (!$storedfile = $fs->get_file($this->context->id, 'backup', 'activity', 0, $filepath, $filename)) {

            if ($filepath === '/' and $filename === '.') {

                $storedfile = new virtual_root_file($this->context->id, 'backup', 'activity', 0);

            } else {

                // not found

                return null;

            }

        }

        $downloadable = has_capability('moodle/backup:downloadfile', $this->context);

        $uploadable   = has_capability('moodle/restore:uploadfile', $this->context);

        $urlbase = $CFG->wwwroot.'/pluginfile.php';

        return new file_info_stored($this->browser, $this->context, $storedfile, $urlbase, get_string('activitybackup', 'repository'), false, $downloadable, $uploadable, false);

    }

    /**

     * Returns localised visible name.

     *

     * @return string

     */

    public function get_visible_name() {

        return $this->cm->get_formatted_name().' ('.$this->cm->get_module_type_name().')';

    }

    /**

     * Whether or not files or directories can be added

     *

     * @return bool

     */

    public function is_writable() {

        return false;

    }

    /**

     * Whether or not this is an emtpy area

     *

     * @return bool

     */

    public function is_empty_area() {

        if ($child = $this->get_area_backup(0, '/', '.')) {

            if (!$child->is_empty_area()) {

                return false;

            }

        }

        if ($child = $this->get_area_intro(0, '/', '.')) {

            if (!$child->is_empty_area()) {

                return false;

            }

        }

        foreach ($this->areas as $area=>$desctiption) {

            if ($child = $this->get_file_info('mod_'.$this->modname, $area, null, null, null)) {

                if (!$child->is_empty_area()) {

                    return false;

                }

            }

        }

        return true;

    }

    /**

     * Whether or not this is a directory

     *

     * @return bool

     */

    public function is_directory() {

        return true;

    }

    /**

     * Returns list of children.

     *

     * @return array of file_info instances

     */

    public function get_children() {

        return $this->get_filtered_children('*', false, true);

    }

    /**

     * Help function to return files matching extensions or their count

     *

     * @param string|array $extensions, either '*' or array of lowercase extensions, i.e. array('.gif','.jpg')

     * @param bool|int $countonly if false returns the children, if an int returns just the

     *    count of children but stops counting when $countonly number of children is reached

     * @param bool $returnemptyfolders if true returns items that don't have matching files inside

     * @return array|int array of file_info instances or the count

     */

    private function get_filtered_children($extensions = '*', $countonly = false, $returnemptyfolders = false) {

        global $DB;

        // prepare list of areas including intro and backup

        $areas = array(

            array('mod_'.$this->modname, 'intro'),

            array('backup', 'activity')

        );

        foreach ($this->areas as $area => $desctiption) {

            $areas[] = array('mod_'.$this->modname, $area);

        }

        $params1 = array('contextid' => $this->context->id, 'emptyfilename' => '.');

        list($sql2, $params2) = $this->build_search_files_sql($extensions);

        $children = array();

        foreach ($areas as $area) {

            if (!$returnemptyfolders) {

                // fast pre-check if there are any files in the filearea

                $params1['component'] = $area[0];

                $params1['filearea'] = $area[1];

                if (!$DB->record_exists_sql('SELECT 1 from {files}

                        WHERE contextid = :contextid

                        AND filename <> :emptyfilename

                        AND component = :component

                        AND filearea = :filearea '.$sql2,

                        array_merge($params1, $params2))) {

                    continue;

                }

            }

            if ($child = $this->get_file_info($area[0], $area[1], null, null, null)) {

                if ($returnemptyfolders || $child->count_non_empty_children($extensions)) {

                    $children[] = $child;

                    if ($countonly !== false && count($children) >= $countonly) {

                        break;

                    }

                }

            }

        }

        if ($countonly !== false) {

            return count($children);

        }

        return $children;

    }

    /**

     * Returns list of children which are either files matching the specified extensions

     * or folders that contain at least one such file.

     *

     * @param string|array $extensions either '*' or array of lowercase extensions, i.e. array('.gif','.jpg')

     * @return array of file_info instances

     */

    public function get_non_empty_children($extensions = '*') {

        if ($this->nonemptychildren !== null) {

            return $this->nonemptychildren;

        }

        $this->nonemptychildren = $this->get_filtered_children($extensions);

        return $this->nonemptychildren;

    }

    /**

     * Returns the number of children which are either files matching the specified extensions

     * or folders containing at least one such file.

     *

     * @param string|array $extensions for example '*' or array('.gif','.jpg')

     * @param int $limit stop counting after at least $limit non-empty children are found

     * @return int

     */

    public function count_non_empty_children($extensions = '*', $limit = 1) {

        if ($this->nonemptychildren !== null) {

            return count($this->nonemptychildren);

        }

        return $this->get_filtered_children($extensions, $limit);

    }

    /**

     * Returns parent file_info instance

     *

     * @return file_info|null file_info or null for root

     */

    public function get_parent() {

        $parent = $this->context->get_parent_context();

        return $this->browser->get_file_info($parent);

    }

}