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/>.

/**

 * This file contains a class definition for the LISResult container resource

 *

 * @package    ltiservice_gradebookservices

 * @copyright  2017 Cengage Learning http://www.cengage.com

 * @author     Dirk Singels, Diego del Blanco, Claude Vervoort

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

 */

namespace ltiservice_gradebookservices\local\resources;

use ltiservice_gradebookservices\local\service\gradebookservices;

use mod_lti\local\ltiservice\resource_base;

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

/**

 * A resource implementing LISResult container.

 *

 * @package    ltiservice_gradebookservices

 * @copyright  2017 Cengage Learning http://www.cengage.com

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

 */

class scores extends resource_base {

    /**

     * Class constructor.

     *

     * @param \ltiservice_gradebookservices\local\service\gradebookservices $service Service instance

     */

    public function __construct($service) {

        parent::__construct($service);

        $this->id = 'Score.collection';

        $this->template = '/{context_id}/lineitems/{item_id}/lineitem/scores';

        $this->variables[] = 'Scores.url';

        $this->formats[] = 'application/vnd.ims.lis.v1.scorecontainer+json';

        $this->formats[] = 'application/vnd.ims.lis.v1.score+json';

        $this->methods[] = 'POST';

    }

    /**

     * Execute the request for this resource.

     *

     * @param \mod_lti\local\ltiservice\response $response  Response object for this request.

     */

    public function execute($response) {

        global $CFG, $DB;

        $params = $this->parse_template();

        $contextid = $params['context_id'];

        $itemid = $params['item_id'];

        // GET is disabled by the moment, but we have the code ready

        // for a future implementation.

        $isget = $response->get_request_method() === 'GET';

        if ($isget) {

            $contenttype = $response->get_accept();

        } else {

            $contenttype = $response->get_content_type();

        }

        $container = empty($contenttype) || ($contenttype === $this->formats[0]);

        // We will receive typeid when working with LTI 1.x, if not the we are in LTI 2.

        $typeid = optional_param('type_id', null, PARAM_ALPHANUM);

        $scope = gradebookservices::SCOPE_GRADEBOOKSERVICES_SCORE;

        try {

            if (!$this->check_tool($typeid, $response->get_request_data(), array($scope))) {

                throw new \Exception(null, 401);

            }

            $typeid = $this->get_service()->get_type()->id;

            if (empty($contextid) || !($container ^ ($response->get_request_method() === self::HTTP_POST)) ||

                    (!empty($contenttype) && !in_array($contenttype, $this->formats))) {

                throw new \Exception('No context or unsupported content type', 400);

            }

            if (!($course = $DB->get_record('course', array('id' => $contextid), 'id', IGNORE_MISSING))) {

                throw new \Exception("Not Found: Course {$contextid} doesn't exist", 404);

            }

            if (!$this->get_service()->is_allowed_in_context($typeid, $course->id)) {

                throw new \Exception('Not allowed in context', 403);

            }

            if (!$DB->record_exists('grade_items', array('id' => $itemid))) {

                throw new \Exception("Not Found: Grade item {$itemid} doesn't exist", 404);

            }

            $item = $this->get_service()->get_lineitem($contextid, $itemid, $typeid);

            if ($item === false) {

                throw new \Exception('Line item does not exist', 404);

            }

            $gbs = gradebookservices::find_ltiservice_gradebookservice_for_lineitem($itemid);

            $ltilinkid = null;

            if (isset($item->iteminstance)) {

                $ltilinkid = $item->iteminstance;

            } else if ($gbs && isset($gbs->ltilinkid)) {

                $ltilinkid = $gbs->ltilinkid;

            }

            if ($ltilinkid != null) {

                if (is_null($typeid)) {

                    if (isset($item->iteminstance) && (!gradebookservices::check_lti_id($ltilinkid, $item->courseid,

                            $this->get_service()->get_tool_proxy()->id))) {

                        $response->set_code(403);

                        $response->set_reason("Invalid LTI id supplied.");

                        return;

                    }

                } else {

                    if (isset($item->iteminstance) && (!gradebookservices::check_lti_1x_id($ltilinkid, $item->courseid,

                            $typeid))) {

                        $response->set_code(403);

                        $response->set_reason("Invalid LTI id supplied.");

                        return;

                    }

                }

            }

            $json = '[]';

            require_once($CFG->libdir.'/gradelib.php');

            switch ($response->get_request_method()) {

                case 'GET':

                    $response->set_code(405);

                    $response->set_reason("GET requests are not allowed.");

                    break;

                case 'POST':

                    try {

                        $json = $this->get_json_for_post_request($response, $response->get_request_data(), $item, $contextid,

                            $typeid);

                        $response->set_content_type($this->formats[1]);

                    } catch (\Exception $e) {

                        $response->set_code($e->getCode());

                        $response->set_reason($e->getMessage());

                    }

                    break;

                default:  // Should not be possible.

                    $response->set_code(405);

                    $response->set_reason("Invalid request method specified.");

                    return;

            }

            $response->set_body($json);

        } catch (\Exception $e) {

            $response->set_code($e->getCode());

            $response->set_reason($e->getMessage());

        }

    }

    /**

     * Generate the JSON for a POST request.

     *

     * @param \mod_lti\local\ltiservice\response $response Response object for this request.

     * @param string $body POST body

     * @param object $item Grade item instance

     * @param string $contextid

     * @param string $typeid

     *

     * @throws \Exception

     */

    private function get_json_for_post_request($response, $body, $item, $contextid, $typeid) {

        $score = json_decode($body);

        if (empty($score) ||

                !isset($score->userId) ||

                !isset($score->timestamp) ||

                !isset($score->gradingProgress) ||

                !isset($score->activityProgress) ||

                !isset($score->timestamp) ||

                isset($score->timestamp) && !gradebookservices::validate_iso8601_date($score->timestamp) ||

                (isset($score->scoreGiven) && !is_numeric($score->scoreGiven)) ||

                (isset($score->scoreGiven) && !isset($score->scoreMaximum)) ||

                (isset($score->scoreMaximum) && !is_numeric($score->scoreMaximum)) ||

                (!gradebookservices::is_user_gradable_in_course($contextid, $score->userId))

                ) {

            throw new \Exception('Incorrect score received' . $body, 400);

        }

        $score->timemodified = intval($score->timestamp);

        if (!isset($score->scoreMaximum)) {

            $score->scoreMaximum = 1;

        }

        $response->set_code(200);

        $grade = \grade_grade::fetch(array('itemid' => $item->id, 'userid' => $score->userId));

        if ($grade &&  !empty($grade->timemodified)) {

            if ($grade->timemodified >= strtotime($score->timestamp)) {

                $exmsg = "Refusing score with an earlier timestamp for item " . $item->id . " and user " . $score->userId;

                throw new \Exception($exmsg, 409);

            }

        }

        if (isset($score->scoreGiven)) {

            if ($score->gradingProgress != 'FullyGraded') {

                $score->scoreGiven = null;

            }

        }

        $this->get_service()->save_grade_item($item, $score, $score->userId);

    }

    /**

     * Parse a value for custom parameter substitution variables.

     *

     * @param string $value String to be parsed

     *

     * @return string

     */

    public function parse_value($value) {

        global $COURSE, $CFG;

        if (strpos($value, '$Scores.url') !== false) {

            require_once($CFG->libdir . '/gradelib.php');

            $resolved = '';

            $this->params['context_id'] = $COURSE->id;

            $id = optional_param('id', 0, PARAM_INT); // Course Module ID.

            if (!empty($id)) {

                $cm = get_coursemodule_from_id('lti', $id, 0, false, MUST_EXIST);

                $id = $cm->instance;

                $item = grade_get_grades($COURSE->id, 'mod', 'lti', $id);

                if ($item && $item->items) {

                    $this->params['item_id'] = $item->items[0]->id;

                    $resolved = parent::get_endpoint();

                }

            }

            $value = str_replace('$Scores.url', $resolved, $value);

        }

        return $value;

    }

}