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/>.

/**

 * Question behaviour that is like the interactive behaviour, but where the

 * student is credited for parts of the question they got right on earlier tries.

 *

 * @package    qbehaviour

 * @subpackage interactivecountback

 * @copyright  2009 The Open University

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

 */

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

require_once(__DIR__ . '/../interactive/behaviour.php');

/**

 * Question behaviour for interactive mode with count-back scoring.

 *

 * As an example, suppose we have a matching question with 4 parts, and 3 tries

 * (penalty 1/3), and the question is worth 12 marks (so, 3 marks for each part).

 * Suppose also that:

 *  - on the first try, the student gets the first two parts right, and the

 *    other two wrong.

 *  - on the second try, they are sure they got the first part right, so keep

 *    their answer the same, but they change their answer to the second part.

 *    They also get the answer to the thrid part right on this try, but still

 *    get the 4th part wrong.

 *  - On the final try, they get the first 3 parts right, but the 4th part still

 *    wrong.

 * We want to grade them as follows.

 *  - For the first part, they were right first time, and did not change their

 *    answer, so we credit that part as right first time: 3/3

 *  - For the second part, although they were right first time, they then changed

 *    their mind, an only finally got it right on the third try, so 1/3.

 *  - For the third part, they got it right on the second try, and then did not

 *    change their answer, so 2/3.

 *  - For the last part, they were wrong at the last try, so 0/3.

 * So, total mark is 6/12. (Really, a fraction of 0.5.)

 *

 * Of course, the details of the grading are actually up to the particular

 * question type. The point is that the final grade can take into account all

 * of the tries the student made.

 *

 * @copyright  2009 The Open University

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

 */

class qbehaviour_interactivecountback extends qbehaviour_interactive {

    public function is_compatible_question(question_definition $question) {

        return $question instanceof question_automatically_gradable_with_countback;

    }

    protected function adjust_fraction($fraction, question_attempt_pending_step $pendingstep) {

        $totaltries = $this->qa->get_step(0)->get_behaviour_var('_triesleft');

        $responses = array();

        $lastsave = array();

        foreach ($this->qa->get_step_iterator() as $step) {

            if ($step->has_behaviour_var('submit') &&

                    $step->get_state() != question_state::$invalid) {

                $responses[] = $step->get_qt_data();

                $lastsave = array();

            } else {

                $lastsave = $step->get_qt_data();

            }

        }

        $lastresponse = $pendingstep->get_qt_data();

        if (!empty($lastresponse)) {

            $responses[] = $lastresponse;

        } else if (!empty($lastsave)) {

            $responses[] = $lastsave;

        }

        return $this->question->compute_final_grade($responses, $totaltries);

    }

}