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/>.

namespace core_contentbank;

use core\event\contentbank_content_created;

use core\event\contentbank_content_deleted;

use core\event\contentbank_content_viewed;

use stored_file;

use moodle_url;

/**

 * Content type manager class

 *

 * @package    core_contentbank

 * @copyright  2020 Amaia Anabitarte <amaia@moodle.com>

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

 */

abstract class contenttype {

    /** @var string Constant representing whether the plugin implements uploading feature */

    const CAN_UPLOAD = 'upload';

    /** @var string Constant representing whether the plugin implements edition feature */

    const CAN_EDIT = 'edit';

    /**

     * @var string Constant representing whether the plugin implements download feature

     * @since  Moodle 3.10

     */

    const CAN_DOWNLOAD = 'download';

    /**

     * @var string Constant representing whether the plugin implements copy feature

     * @since  Moodle 4.3

     */

    const CAN_COPY = 'copy';

    /** @var \context This contenttype's context. **/

    protected $context = null;

    /**

     * Content type constructor

     *

     * @param \context $context Optional context to check (default null)

     */

    public function __construct(?\context $context = null) {

        if (empty($context)) {

            $context = \context_system::instance();

        }

        $this->context = $context;

    }

    /**

     * Fills content_bank table with appropiate information.

     *

     * @throws dml_exception A DML specific exception is thrown for any creation error.

     * @param \stdClass $record An optional content record compatible object (default null)

     * @return content  Object with content bank information.

     */

    public function create_content(?\stdClass $record = null): content {

        global $USER, $DB, $CFG;

        $entry = new \stdClass();

        if (isset($record->visibility)) {

            $entry->visibility = $record->visibility;

        } else {

            $usercreated = $record->usercreated ?? $USER->id;

            $entry->visibility = get_user_preferences('core_contentbank_visibility',

                $CFG->defaultpreference_core_contentbank_visibility, $usercreated);

        }

        $entry->contenttype = $this->get_contenttype_name();

        $entry->contextid = $this->context->id;

        $entry->name = $record->name ?? '';

        $entry->usercreated = $record->usercreated ?? $USER->id;

        $entry->timecreated = time();

        $entry->usermodified = $entry->usercreated;

        $entry->timemodified = $entry->timecreated;

        $entry->configdata = $record->configdata ?? '';

        $entry->instanceid = $record->instanceid ?? 0;

        $entry->id = $DB->insert_record('contentbank_content', $entry);

        $classname = '\\'.$entry->contenttype.'\\content';

        $content = new $classname($entry);

        // Trigger an event for creating the content.

        $event = contentbank_content_created::create_from_record($content->get_content());

        $event->trigger();

        return $content;

    }

    /**

     * Create a new content from an uploaded file.

     *

     * @throws file_exception If file operations fail

     * @throws dml_exception if the content creation fails

     * @param stored_file $file the uploaded file

     * @param \stdClass|null $record an optional content record

     * @return content  Object with content bank information.

     */

    public function upload_content(stored_file $file, ?\stdClass $record = null): content {

        if (empty($record)) {

            $record = new \stdClass();

            $record->name = $file->get_filename();

        }

        $content = $this->create_content($record);

        try {

            $content->import_file($file);

        } catch (\moodle_exception $e) {

            $this->delete_content($content);

            throw new \moodle_exception($e->errorcode);

        }

        return $content;

    }

    /**

     * Replace a content using an uploaded file.

     *

     * @throws file_exception If file operations fail

     * @throws dml_exception if the content creation fails

     * @param stored_file $file the uploaded file

     * @param content $content the original content record

     * @return content Object with the updated content bank information.

     */

    public function replace_content(stored_file $file, content $content): content {

        $content->import_file($file);

        $content->update_content();

        return $content;

    }

    /**

     * Delete this content from the content_bank.

     * This method can be overwritten by the plugins if they need to delete specific information.

     *

     * @param  content $content The content to delete.

     * @return boolean true if the content has been deleted; false otherwise.

     */

    public function delete_content(content $content): bool {

        global $DB;

        // Delete the file if it exists.

        if ($file = $content->get_file()) {

            $file->delete();

        }

        // Delete the contentbank DB entry.

        $result = $DB->delete_records('contentbank_content', ['id' => $content->get_id()]);

        if ($result) {

            // Trigger an event for deleting this content.

            $record = $content->get_content();

            $event = contentbank_content_deleted::create([

                'objectid' => $content->get_id(),

                'relateduserid' => $record->usercreated,

                'context' => \context::instance_by_id($record->contextid),

                'other' => [

                    'contenttype' => $content->get_content_type(),

                    'name' => $content->get_name()

                ]

            ]);

            $event->add_record_snapshot('contentbank_content', $record);

            $event->trigger();

        }

        return $result;

    }

    /**

     * Rename this content from the content_bank.

     * This method can be overwritten by the plugins if they need to change some other specific information.

     *

     * @param  content $content The content to rename.

     * @param  string $name  The name of the content.

     * @return boolean true if the content has been renamed; false otherwise.

     */

    public function rename_content(content $content, string $name): bool {

        return $content->set_name($name);

    }

    /**

     * Move content to another context.

     * This method can be overwritten by the plugins if they need to change some other specific information.

     *

     * @param  content $content The content to rename.

     * @param  \context $context  The new context.

     * @return boolean true if the content has been renamed; false otherwise.

     */

    public function move_content(content $content, \context $context): bool {

        return $content->set_contextid($context->id);

    }

    /**

     * Returns the contenttype name of this content.

     *

     * @return string   Content type of the current instance

     */

    public function get_contenttype_name(): string {

        $classname = get_class($this);

        $contenttype = explode('\\', $classname);

        return array_shift($contenttype);

    }

    /**

     * Returns the plugin name of the current instance.

     *

     * @return string   Plugin name of the current instance

     */

    public function get_plugin_name(): string {

        $contenttype = $this->get_contenttype_name();

        $plugin = explode('_', $contenttype);

        return array_pop($plugin);

    }

    /**

     * Returns the URL where the content will be visualized.

     *

     * @param  content $content The content to be displayed.

     * @return string           URL where to visualize the given content.

     */

    public function get_view_url(content $content): string {

        return new moodle_url('/contentbank/view.php', ['id' => $content->get_id()]);

    }

    /**

     * Returns the HTML content to add to view.php visualizer.

     *

     * @param  content $content The content to be displayed.

     * @return string           HTML code to include in view.php.

     */

    public function get_view_content(content $content): string {

        global $PAGE;

        // Trigger an event for viewing this content.

        $event = contentbank_content_viewed::create_from_record($content->get_content());

        $event->trigger();

        if ($content->has_custom_fields()) {

            $renderer = $PAGE->get_renderer('core');

            $renderable = new \core_contentbank\output\customfields($content);

            return $renderer->render($renderable);

        }

        return '';

    }

    /**

     * Returns the URL to download the content.

     *

     * @since  Moodle 3.10

     * @param  content $content The content to be downloaded.

     * @return string           URL with the content to download.

     */

    public function get_download_url(content $content): string {

        $downloadurl = '';

        $file = $content->get_file();

        if (!empty($file)) {

            $url = \moodle_url::make_pluginfile_url(

                $file->get_contextid(),

                $file->get_component(),

                $file->get_filearea(),

                $file->get_itemid(),

                $file->get_filepath(),

                $file->get_filename()

            );

            $downloadurl = $url->out(false);

        }

        return $downloadurl;

    }

    /**

     * Returns the HTML code to render the icon for content bank contents.

     *

     * @param  content $content The content to be displayed.

     * @return string               HTML code to render the icon

     */

    public function get_icon(content $content): string {

        global $OUTPUT;

        return $OUTPUT->image_url('f/unknown')->out(false);

    }

    /**

     * Returns user has access capability for the main content bank and the content itself (base on is_access_allowed from plugin).

     *

     * @return bool     True if content could be accessed. False otherwise.

     */

    final public function can_access(): bool {

        $classname = 'contenttype/'.$this->get_plugin_name();

        $capability = $classname.":access";

        $hascapabilities = has_capability('moodle/contentbank:access', $this->context)

            && has_capability($capability, $this->context);

        return $hascapabilities && $this->is_access_allowed();

    }

    /**

     * Returns user has access capability for the content itself.

     *

     * @return bool     True if content could be accessed. False otherwise.

     */

    protected function is_access_allowed(): bool {

        // Plugins can overwrite this function to add any check they need.

        return true;

    }

    /**

     * Returns the user has permission to upload new content.

     *

     * @return bool     True if content could be uploaded. False otherwise.

     */

    final public function can_upload(): bool {

        if (!$this->is_feature_supported(self::CAN_UPLOAD)) {

            return false;

        }

        if (!$this->can_access()) {

            return false;

        }

        $classname = 'contenttype/'.$this->get_plugin_name();

        $uploadcap = $classname.':upload';

        $hascapabilities = has_capability('moodle/contentbank:upload', $this->context)

            && has_capability($uploadcap, $this->context);

        return $hascapabilities && $this->is_upload_allowed();

    }

    /**

     * Returns plugin allows uploading.

     *

     * @return bool     True if plugin allows uploading. False otherwise.

     */

    protected function is_upload_allowed(): bool {

        // Plugins can overwrite this function to add any check they need.

        return true;

    }

    /**

     * Check if the user can delete this content.

     *

     * @param  content $content The content to be deleted.

     * @return bool True if content could be uploaded. False otherwise.

     */

    final public function can_delete(content $content): bool {

        global $USER;

        if ($this->context->id != $content->get_content()->contextid) {

            // The content has to have exactly the same context as this contenttype.

            return false;

        }

        $hascapability = has_capability('moodle/contentbank:deleteanycontent', $this->context);

        if ($content->get_content()->usercreated == $USER->id) {

            // This content has been created by the current user; check if she can delete her content.

            $hascapability = $hascapability || has_capability('moodle/contentbank:deleteowncontent', $this->context);

        }

        return $hascapability && $this->is_delete_allowed($content);

    }

    /**

     * Returns if content allows deleting.

     *

     * @param  content $content The content to be deleted.

     * @return bool True if content allows uploading. False otherwise.

     */

    protected function is_delete_allowed(content $content): bool {

        // Plugins can overwrite this function to add any check they need.

        return true;

    }

    /**

     * Check if the user can managed this content.

     *

     * @param  content $content The content to be managed.

     * @return bool     True if content could be managed. False otherwise.

     */

    final public function can_manage(content $content): bool {

        global $USER;

        if ($this->context->id != $content->get_content()->contextid) {

            // The content has to have exactly the same context as this contenttype.

            return false;

        }

        // Check main contentbank management permission.

        $hascapability = has_capability('moodle/contentbank:manageanycontent', $this->context);

        if ($content->get_content()->usercreated == $USER->id) {

            // This content has been created by the current user; check if they can manage their content.

            $hascapability = $hascapability || has_capability('moodle/contentbank:manageowncontent', $this->context);

        }

        return $hascapability && $this->is_manage_allowed($content);

    }

    /**

     * Returns if content allows managing.

     *

     * @param  content $content The content to be managed.

     * @return bool True if content allows uploading. False otherwise.

     */

    protected function is_manage_allowed(content $content): bool {

        // Plugins can overwrite this function to add any check they need.

        return true;

    }

    /**

     * Returns whether or not the user has permission to use the editor.

     * This function will be called with the content to be edited as parameter,

     * or null when is checking permission to create a new content using the editor.

     *

     * @param  content $content The content to be edited or null when creating a new content.

     * @return bool     True if the user can edit content. False otherwise.

     */

    final public function can_edit(?content $content = null): bool {

        if (!$this->is_feature_supported(self::CAN_EDIT)) {

            return false;

        }

        if (!$this->can_access()) {

            return false;

        }

        if (!is_null($content) && !$this->can_manage($content)) {

            return false;

        }

        $classname = 'contenttype/'.$this->get_plugin_name();

        $editioncap = $classname.':useeditor';

        $hascapabilities = has_all_capabilities(['moodle/contentbank:useeditor', $editioncap], $this->context);

        return $hascapabilities && $this->is_edit_allowed($content);

    }

    /**

     * Returns plugin allows edition.

     *

     * @param  content $content The content to be edited.

     * @return bool     True if plugin allows edition. False otherwise.

     */

    protected function is_edit_allowed(?content $content): bool {

        // Plugins can overwrite this function to add any check they need.

        return true;

    }

    /**

     * Returns whether or not the user has permission to download the content.

     *

     * @since  Moodle 3.10

     * @param  content $content The content to be downloaded.

     * @return bool    True if the user can download the content. False otherwise.

     */

    final public function can_download(content $content): bool {

        if (!$this->is_feature_supported(self::CAN_DOWNLOAD)) {

            return false;

        }

        if (!$this->can_access()) {

            return false;

        }

        $hascapability = has_capability('moodle/contentbank:downloadcontent', $this->context);

        return $hascapability && $this->is_download_allowed($content);

    }

    /**

     * Returns whether or not the user has permission to copy the content.

     *

     * @since  Moodle 4.3

     * @param  content $content The content to be copied.

     * @return bool    True if the user can copy the content. False otherwise.

     */

    final public function can_copy(content $content): bool {

        global $USER;

        if (!$this->is_feature_supported(self::CAN_COPY)) {

            return false;

        }

        if (!$this->can_access()) {

            return false;

        }

        if (!$this->is_copy_allowed($content)) {

            return false;

        }

        $hascapability = has_capability('moodle/contentbank:copyanycontent', $this->context);

        if (!$hascapability && ($content->get_content()->usercreated == $USER->id)) {

            $hascapability = has_capability('moodle/contentbank:copycontent', $this->context);

        }

        return $hascapability;

    }

    /**

     * Returns plugin allows downloading.

     *

     * @since  Moodle 3.10

     * @param  content $content The content to be downloaed.

     * @return bool    True if plugin allows downloading. False otherwise.

     */

    protected function is_download_allowed(content $content): bool {

        // Plugins can overwrite this function to add any check they need.

        return true;

    }

    /**

     * Returns plugin allows copying.

     *

     * @since  Moodle 4.3

     * @param  content $content The content to be copied.

     * @return bool    True if plugin allows copying. False otherwise.

     */

    protected function is_copy_allowed(content $content): bool {

        // Plugins can overwrite this function to add any check they need.

        return true;

    }

    /**

     * Returns the plugin supports the feature.

     *

     * @param string $feature Feature code e.g CAN_UPLOAD

     * @return bool     True if content could be uploaded. False otherwise.

     */

    final public function is_feature_supported(string $feature): bool {

        return in_array($feature, $this->get_implemented_features());

    }

    /**

     * Return an array of implemented features by the plugins.

     *

     * @return array

     */

    abstract protected function get_implemented_features(): array;

    /**

     * Return an array of extensions the plugins could manage.

     *

     * @return array

     */

    abstract public function get_manageable_extensions(): array;

    /**

     * Returns the list of different types of the given content type.

     *

     * A content type can have one or more options for creating content. This method will report all of them or only the content

     * type itself if it has no other options.

     *

     * @return array An object for each type:

     *     - string typename: descriptive name of the type.

     *     - string typeeditorparams: params required by this content type editor.

     *     - url typeicon: this type icon.

     */

    abstract public function get_contenttype_types(): array;

}