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_plugin_manager;

use stored_file;

use context;

/**

 * Content bank class

 *

 * @package    core_contentbank

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

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

 */

class contentbank {

    /** @var array All the context levels allowed in the content bank */

    private const ALLOWED_CONTEXT_LEVELS = [CONTEXT_SYSTEM, CONTEXT_COURSECAT, CONTEXT_COURSE];

    /** @var array Enabled content types. */

    private $enabledcontenttypes = null;

    /**

     * Obtains the list of core_contentbank_content objects currently active.

     *

     * The list does not include players which are disabled.

     *

     * @return string[] Array of contentbank contenttypes.

     */

    public function get_enabled_content_types(): array {

        if (!is_null($this->enabledcontenttypes)) {

            return $this->enabledcontenttypes;

        }

        $enabledtypes = \core\plugininfo\contenttype::get_enabled_plugins();

        $types = [];

        foreach ($enabledtypes as $name) {

            $contenttypeclassname = "\\contenttype_$name\\contenttype";

            $contentclassname = "\\contenttype_$name\\content";

            if (class_exists($contenttypeclassname) && class_exists($contentclassname)) {

                $types[$contenttypeclassname] = $name;

            }

        }

        return $this->enabledcontenttypes = $types;

    }

    /**

     * Obtains an array of supported extensions by active plugins.

     *

     * @return array The array with all the extensions supported and the supporting plugin names.

     */

    public function load_all_supported_extensions(): array {

        $extensionscache = \cache::make('core', 'contentbank_enabled_extensions');

        $supportedextensions = $extensionscache->get('enabled_extensions');

        if ($supportedextensions === false) {

            // Load all enabled extensions.

            $supportedextensions = [];

            foreach ($this->get_enabled_content_types() as $type) {

                $classname = "\\contenttype_$type\\contenttype";

                $contenttype = new $classname;

                if ($contenttype->is_feature_supported($contenttype::CAN_UPLOAD)) {

                    $extensions = $contenttype->get_manageable_extensions();

                    foreach ($extensions as $extension) {

                        if (array_key_exists($extension, $supportedextensions)) {

                            $supportedextensions[$extension][] = $type;

                        } else {

                            $supportedextensions[$extension] = [$type];

                        }

                    }

                }

            }

            $extensionscache->set('enabled_extensions', $supportedextensions);

        }

        return $supportedextensions;

    }

    /**

     * Obtains an array of supported extensions in the given context.

     *

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

     * @return array The array with all the extensions supported and the supporting plugin names.

     */

    public function load_context_supported_extensions(context $context = null): array {

        $extensionscache = \cache::make('core', 'contentbank_context_extensions');

        $contextextensions = $extensionscache->get($context->id);

        if ($contextextensions === false) {

            $contextextensions = [];

            $supportedextensions = $this->load_all_supported_extensions();

            foreach ($supportedextensions as $extension => $types) {

                foreach ($types as $type) {

                    $classname = "\\contenttype_$type\\contenttype";

                    $contenttype = new $classname($context);

                    if ($contenttype->can_upload()) {

                        $contextextensions[$extension] = $type;

                        break;

                    }

                }

            }

            $extensionscache->set($context->id, $contextextensions);

        }

        return $contextextensions;

    }

    /**

     * Obtains a string with all supported extensions by active plugins.

     * Mainly to use as filepicker options parameter.

     *

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

     * @return string A string with all the extensions supported.

     */

    public function get_supported_extensions_as_string(context $context = null) {

        $supported = $this->load_context_supported_extensions($context);

        $extensions = array_keys($supported);

        return implode(',', $extensions);

    }

    /**

     * Returns the file extension for a file.

     *

     * @param  string $filename The name of the file

     * @return string The extension of the file

     */

    public function get_extension(string $filename) {

        $dot = strrpos($filename, '.');

        if ($dot === false) {

            return '';

        }

        return strtolower(substr($filename, $dot));

    }

    /**

     * Get the first content bank plugin supports a file extension.

     *

     * @param string $extension Content file extension

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

     * @return string contenttype name supports the file extension or null if the extension is not supported by any allowed plugin.

     */

    public function get_extension_supporter(string $extension, context $context = null): ?string {

        $supporters = $this->load_context_supported_extensions($context);

        if (array_key_exists($extension, $supporters)) {

            return $supporters[$extension];

        }

        return null;

    }

    /**

     * Find the contents with %$search% in the contextid defined.

     * If contextid and search are empty, all contents are returned.

     * In all the cases, only the contents for the enabled contentbank-type plugins are returned.

     * No content-type permissions are validated here. It is the caller responsability to check that the user can access to them.

     * The only validation done here is, for each content, a call to the method $content->is_view_allowed().

     *

     * @param  string|null $search Optional string to search (for now it will search only into the name).

     * @param  int $contextid Optional contextid to search.

     * @param  array $contenttypenames Optional array with the list of content-type names to search.

     * @return array The contents for the enabled contentbank-type plugins having $search as name and placed in $contextid.

     */

    public function search_contents(?string $search = null, ?int $contextid = 0, ?array $contenttypenames = null): array {

        global $DB;

        $contents = [];

        // Get only contents for enabled content-type plugins.

        $contenttypes = [];

        $enabledcontenttypes = $this->get_enabled_content_types();

        foreach ($enabledcontenttypes as $contenttypename) {

            if (empty($contenttypenames) || in_array($contenttypename, $contenttypenames)) {

                $contenttypes[] = "contenttype_$contenttypename";

            }

        }

        if (empty($contenttypes)) {

            // Early return if there are no content-type plugins enabled.

            return $contents;

        }

        list($sqlcontenttypes, $params) = $DB->get_in_or_equal($contenttypes, SQL_PARAMS_NAMED);

        $sql = " contenttype $sqlcontenttypes ";

        // Filter contents on this context (if defined).

        if (!empty($contextid)) {

            $params['contextid'] = $contextid;

            $sql .= ' AND contextid = :contextid ';

        }

        // Search for contents having this string (if defined).

        if (!empty($search)) {

            $sql .= ' AND ' . $DB->sql_like('name', ':name', false, false);

            $params['name'] = '%' . $DB->sql_like_escape($search) . '%';

        }

        $records = $DB->get_records_select('contentbank_content', $sql, $params, 'name ASC');

        foreach ($records as $record) {

            $content = $this->get_content_from_id($record->id);

            if ($content->is_view_allowed()) {

                $contents[] = $content;

            }

        }

        return $contents;

    }

    /**

     * Return all the context where a user has all the given capabilities.

     *

     * @param  string $capability The capability the user needs to have.

     * @param  int|null $userid Optional userid. $USER by default.

     * @return array Array of the courses and course categories where the user has the given capability.

     */

    public function get_contexts_with_capabilities_by_user($capability = 'moodle/contentbank:access', $userid = null): array {

        global $USER;

        if (!$userid) {

            $userid = $USER->id;

        }

        $categoriescache = \cache::make('core', 'contentbank_allowed_categories');

        $coursescache = \cache::make('core', 'contentbank_allowed_courses');

        $categories = $categoriescache->get($userid);

        $courses = $coursescache->get($userid);

        if ($categories === false || $courses === false) {

            // Required fields for preloading the context record.

            $contextfields = 'ctxid, ctxpath, ctxdepth, ctxlevel, ctxinstance, ctxlocked';

            list($categories, $courses) = get_user_capability_contexts($capability, true, $userid, true,

                "fullname, {$contextfields}", "name, {$contextfields}", 'fullname', 'name');

            $categoriescache->set($userid, $categories);

            $coursescache->set($userid, $courses);

        }

        return [$categories, $courses];

    }

    /**

     * Create content from a file information.

     *

     * @param \context $context Context where to upload the file and content.

     * @param int $userid Id of the user uploading the file.

     * @param stored_file $file The file to get information from

     * @return content

     */

    public function create_content_from_file(\context $context, int $userid, stored_file $file): ?content {

        global $USER;

        if (empty($userid)) {

            $userid = $USER->id;

        }

        // Get the contenttype to manage given file's extension.

        $filename = $file->get_filename();

        $extension = $this->get_extension($filename);

        $plugin = $this->get_extension_supporter($extension, $context);

        $classname = '\\contenttype_'.$plugin.'\\contenttype';

        $record = new \stdClass();

        $record->name = $filename;

        $record->usercreated = $userid;

        $contentype = new $classname($context);

        $content = $contentype->upload_content($file, $record);

        $event = \core\event\contentbank_content_uploaded::create_from_record($content->get_content());

        $event->trigger();

        return $content;

    }

    /**

     * Delete content bank content by context.

     *

     * @param context $context The context to delete content from.

     * @return bool

     */

    public function delete_contents(context $context): bool {

        global $DB;

        $result = true;

        $records = $DB->get_records('contentbank_content', ['contextid' => $context->id]);

        foreach ($records as $record) {

            $content = $this->get_content_from_id($record->id);

            $contenttype = $content->get_content_type_instance();

            if (!$contenttype->delete_content($content)) {

                $result = false;

            }

        }

        return $result;

    }

    /**

     * Move content bank content from a context to another.

     *

     * @param context $from The context to get content from.

     * @param context $to The context to move content to.

     * @return bool

     */

    public function move_contents(context $from, context $to): bool {

        global $DB;

        $result = true;

        $records = $DB->get_records('contentbank_content', ['contextid' => $from->id]);

        foreach ($records as $record) {

            $content = $this->get_content_from_id($record->id);

            $contenttype = $content->get_content_type_instance();

            if (!$contenttype->move_content($content, $to)) {

                $result = false;

            }

        }

        return $result;

    }

    /**

     * Get the list of content types that have the requested feature.

     *

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

     * @param null|\context $context Optional context to check the permission to use the feature.

     * @param bool $enabled Whether check only the enabled content types or all of them.

     *

     * @return string[] List of content types where the user has permission to access the feature.

     */

    public function get_contenttypes_with_capability_feature(string $feature, \context $context = null, bool $enabled = true): array {

        $contenttypes = [];

        // Check enabled content types or all of them.

        if ($enabled) {

            $contenttypestocheck = $this->get_enabled_content_types();

        } else {

            $plugins = core_plugin_manager::instance()->get_plugins_of_type('contenttype');

            foreach ($plugins as $plugin) {

                $contenttypeclassname = "\\{$plugin->type}_{$plugin->name}\\contenttype";

                $contenttypestocheck[$contenttypeclassname] = $plugin->name;

            }

        }

        foreach ($contenttypestocheck as $classname => $name) {

            $contenttype = new $classname($context);

            // The method names that check the features permissions must follow the pattern can_feature.

            if ($contenttype->{"can_$feature"}()) {

                $contenttypes[$classname] = $name;

            }

        }

        return $contenttypes;

    }

    /**

     * Return a content class form a content id.

     *

     * @throws coding_exception if the ID is not valid or some class does no exists

     * @param int $id the content id

     * @return content the content class instance

     */

    public function get_content_from_id(int $id): content {

        global $DB;

        $record = $DB->get_record('contentbank_content', ['id' => $id], '*', MUST_EXIST);

        $contentclass = "\\$record->contenttype\\content";

        return new $contentclass($record);

    }

    /**

     * Whether the context is allowed.

     *

     * @param context $context Context to check.

     * @return bool

     */

    public function is_context_allowed(context $context): bool {

        return in_array($context->contextlevel, self::ALLOWED_CONTEXT_LEVELS);

    }

}