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/>.

/**

 * Helper functions for the quiz reports.

 *

 * @package   mod_quiz

 * @copyright 2008 Jamie Pratt

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

 */

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

require_once($CFG->dirroot . '/mod/quiz/lib.php');

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

use mod_quiz\question\display_options;

/**

 * Takes an array of objects and constructs a multidimensional array keyed by

 * the keys it finds on the object.

 * @param array $datum an array of objects with properties on the object

 * including the keys passed as the next param.

 * @param array $keys Array of strings with the names of the properties on the

 * objects in datum that you want to index the multidimensional array by.

 * @param bool $keysunique If there is not only one object for each

 * combination of keys you are using you should set $keysunique to true.

 * Otherwise all the object will be added to a zero based array. So the array

 * returned will have count($keys) + 1 indexs.

 * @return array multidimensional array properly indexed.

 */

function quiz_report_index_by_keys($datum, $keys, $keysunique = true) {

    if (!$datum) {

        return [];

    }

    $key = array_shift($keys);

    $datumkeyed = [];

    foreach ($datum as $data) {

        if ($keys || !$keysunique) {

            $datumkeyed[$data->{$key}][]= $data;

        } else {

            $datumkeyed[$data->{$key}]= $data;

        }

    }

    if ($keys) {

        foreach ($datumkeyed as $datakey => $datakeyed) {

            $datumkeyed[$datakey] = quiz_report_index_by_keys($datakeyed, $keys, $keysunique);

        }

    }

    return $datumkeyed;

}

function quiz_report_unindex($datum) {

    if (!$datum) {

        return $datum;

    }

    $datumunkeyed = [];

    foreach ($datum as $value) {

        if (is_array($value)) {

            $datumunkeyed = array_merge($datumunkeyed, quiz_report_unindex($value));

        } else {

            $datumunkeyed[] = $value;

        }

    }

    return $datumunkeyed;

}

/**

 * Are there any questions in this quiz?

 * @param int $quizid the quiz id.

 */

function quiz_has_questions($quizid) {

    global $DB;

    return $DB->record_exists('quiz_slots', ['quizid' => $quizid]);

}

/**

 * Get the slots of real questions (not descriptions) in this quiz, in order.

 * @param stdClass $quiz the quiz.

 * @return array of slot => objects with fields

 *      ->slot, ->id, ->qtype, ->length, ->number, ->maxmark, ->category (for random questions).

 */

function quiz_report_get_significant_questions($quiz) {

    $quizobj = mod_quiz\quiz_settings::create($quiz->id);

    $structure = \mod_quiz\structure::create_for_quiz($quizobj);

    $slots = $structure->get_slots();

    $qsbyslot = [];

    $number = 1;

    foreach ($slots as $slot) {

        // Ignore 'questions' of zero length.

        if ($slot->length == 0) {

            continue;

        }

        $slotreport = new \stdClass();

        $slotreport->slot = $slot->slot;

        $slotreport->id = $slot->questionid;

        $slotreport->qtype = $slot->qtype;

        $slotreport->length = $slot->length;

        $slotreport->number = $number;

        $number += $slot->length;

        $slotreport->maxmark = $slot->maxmark;

        $slotreport->category = $slot->category;

        $qsbyslot[$slotreport->slot] = $slotreport;

    }

    return $qsbyslot;

}

/**

 * @param stdClass $quiz the quiz settings.

 * @return bool whether, for this quiz, it is possible to filter attempts to show

 *      only those that gave the final grade.

 */

function quiz_report_can_filter_only_graded($quiz) {

    return $quiz->attempts != 1 && $quiz->grademethod != QUIZ_GRADEAVERAGE;

}

/**

 * This is a wrapper for {@link quiz_report_grade_method_sql} that takes the whole quiz object instead of just the grading method

 * as a param. See definition for {@link quiz_report_grade_method_sql} below.

 *

 * @param stdClass $quiz

 * @param string $quizattemptsalias sql alias for 'quiz_attempts' table

 * @return string sql to test if this is an attempt that will contribute towards the grade of the user

 */

function quiz_report_qm_filter_select($quiz, $quizattemptsalias = 'quiza') {

    if ($quiz->attempts == 1) {

        // This quiz only allows one attempt.

        return '';

    }

    return quiz_report_grade_method_sql($quiz->grademethod, $quizattemptsalias);

}

/**

 * Given a quiz grading method return sql to test if this is an

 * attempt that will be contribute towards the grade of the user. Or return an

 * empty string if the grading method is QUIZ_GRADEAVERAGE and thus all attempts

 * contribute to final grade.

 *

 * @param string $grademethod quiz grading method.

 * @param string $quizattemptsalias sql alias for 'quiz_attempts' table

 * @return string sql to test if this is an attempt that will contribute towards the graded of the user

 */

function quiz_report_grade_method_sql($grademethod, $quizattemptsalias = 'quiza') {

    switch ($grademethod) {

        case QUIZ_GRADEHIGHEST :

            return "($quizattemptsalias.state = 'finished' AND NOT EXISTS (

                           SELECT 1 FROM {quiz_attempts} qa2

                            WHERE qa2.quiz = $quizattemptsalias.quiz AND

                                qa2.userid = $quizattemptsalias.userid AND

                                 qa2.state = 'finished' AND (

                COALESCE(qa2.sumgrades, 0) > COALESCE($quizattemptsalias.sumgrades, 0) OR

               (COALESCE(qa2.sumgrades, 0) = COALESCE($quizattemptsalias.sumgrades, 0) AND qa2.attempt < $quizattemptsalias.attempt)

                                )))";

        case QUIZ_GRADEAVERAGE :

            return '';

        case QUIZ_ATTEMPTFIRST :

            return "($quizattemptsalias.state = 'finished' AND NOT EXISTS (

                           SELECT 1 FROM {quiz_attempts} qa2

                            WHERE qa2.quiz = $quizattemptsalias.quiz AND

                                qa2.userid = $quizattemptsalias.userid AND

                                 qa2.state = 'finished' AND

                               qa2.attempt < $quizattemptsalias.attempt))";

        case QUIZ_ATTEMPTLAST :

            return "($quizattemptsalias.state = 'finished' AND NOT EXISTS (

                           SELECT 1 FROM {quiz_attempts} qa2

                            WHERE qa2.quiz = $quizattemptsalias.quiz AND

                                qa2.userid = $quizattemptsalias.userid AND

                                 qa2.state = 'finished' AND

                               qa2.attempt > $quizattemptsalias.attempt))";

    }

}

/**

 * Get the number of students whose score was in a particular band for this quiz.

 * @param number $bandwidth the width of each band.

 * @param int $bands the number of bands

 * @param int $quizid the quiz id.

 * @param \core\dml\sql_join $usersjoins (joins, wheres, params) to get enrolled users

 * @return array band number => number of users with scores in that band.

 */

function quiz_report_grade_bands($bandwidth, $bands, $quizid, \core\dml\sql_join $usersjoins = null) {

    global $DB;

    if (!is_int($bands)) {

        debugging('$bands passed to quiz_report_grade_bands must be an integer. (' .

                gettype($bands) . ' passed.)', DEBUG_DEVELOPER);

        $bands = (int) $bands;

    }

    if ($usersjoins && !empty($usersjoins->joins)) {

        $userjoin = "JOIN {user} u ON u.id = qg.userid

                {$usersjoins->joins}";

        $usertest = $usersjoins->wheres;

        $params = $usersjoins->params;

    } else {

        $userjoin = '';

        $usertest = '1=1';

        $params = [];

    }

    $sql = "

SELECT band, COUNT(1)

FROM (

    SELECT FLOOR(qg.grade / :bandwidth) AS band

      FROM {quiz_grades} qg

    $userjoin

    WHERE $usertest AND qg.quiz = :quizid

) subquery

GROUP BY

    band

ORDER BY

    band";

    $params['quizid'] = $quizid;

    $params['bandwidth'] = $bandwidth;

    $data = $DB->get_records_sql_menu($sql, $params);

    // We need to create array elements with values 0 at indexes where there is no element.

    $data = $data + array_fill(0, $bands + 1, 0);

    ksort($data);

    // Place the maximum (perfect grade) into the last band i.e. make last

    // band for example 9 <= g <=10 (where 10 is the perfect grade) rather than

    // just 9 <= g <10.

    $data[$bands - 1] += $data[$bands];

    unset($data[$bands]);

    // See MDL-60632. When a quiz participant achieves an overall negative grade the chart fails to render.

    foreach ($data as $databand => $datanum) {

        if ($databand < 0) {

            $data["0"] += $datanum; // Add to band 0.

            unset($data[$databand]); // Remove entry below 0.

        }

    }

    return $data;

}

function quiz_report_highlighting_grading_method($quiz, $qmsubselect, $qmfilter) {

    if ($quiz->attempts == 1) {

        return '<p>' . get_string('onlyoneattemptallowed', 'quiz_overview') . '</p>';

    } else if (!$qmsubselect) {

        return '<p>' . get_string('allattemptscontributetograde', 'quiz_overview') . '</p>';

    } else if ($qmfilter) {

        return '<p>' . get_string('showinggraded', 'quiz_overview') . '</p>';

    } else {

        return '<p>' . get_string('showinggradedandungraded', 'quiz_overview',

                '<span class="gradedattempt">' . quiz_get_grading_option_name($quiz->grademethod) .

                '</span>') . '</p>';

    }

}

/**

 * Get the feedback text for a grade on this quiz. The feedback is

 * processed ready for display.

 *

 * @param float $grade a grade on this quiz.

 * @param int $quizid the id of the quiz object.

 * @return string the comment that corresponds to this grade (empty string if there is not one.

 */

function quiz_report_feedback_for_grade($grade, $quizid, $context) {

    global $DB;

    static $feedbackcache = [];

    if (!isset($feedbackcache[$quizid])) {

        $feedbackcache[$quizid] = $DB->get_records('quiz_feedback', ['quizid' => $quizid]);

    }

    // With CBM etc, it is possible to get -ve grades, which would then not match

    // any feedback. Therefore, we replace -ve grades with 0.

    $grade = max($grade, 0);

    $feedbacks = $feedbackcache[$quizid];

    $feedbackid = 0;

    $feedbacktext = '';

    $feedbacktextformat = FORMAT_MOODLE;

    foreach ($feedbacks as $feedback) {

        if ($feedback->mingrade <= $grade && $grade < $feedback->maxgrade) {

            $feedbackid = $feedback->id;

            $feedbacktext = $feedback->feedbacktext;

            $feedbacktextformat = $feedback->feedbacktextformat;

            break;

        }

    }

    // Clean the text, ready for display.

    $formatoptions = new stdClass();

    $formatoptions->noclean = true;

    $feedbacktext = file_rewrite_pluginfile_urls($feedbacktext, 'pluginfile.php',

            $context->id, 'mod_quiz', 'feedback', $feedbackid);

    $feedbacktext = format_text($feedbacktext, $feedbacktextformat, $formatoptions);

    return $feedbacktext;

}

/**

 * Format a number as a percentage out of $quiz->sumgrades

 * @param number $rawgrade the mark to format.

 * @param stdClass $quiz the quiz settings

 * @param bool $round whether to round the results ot $quiz->decimalpoints.

 */

function quiz_report_scale_summarks_as_percentage($rawmark, $quiz, $round = true) {

    if ($quiz->sumgrades == 0) {

        return '';

    }

    if (!is_numeric($rawmark)) {

        return $rawmark;

    }

    $mark = $rawmark * 100 / $quiz->sumgrades;

    if ($round) {

        $mark = quiz_format_grade($quiz, $mark);

    }

    return get_string('percents', 'moodle', $mark);

}

/**

 * Returns an array of reports to which the current user has access to.

 * @return array reports are ordered as they should be for display in tabs.

 */

function quiz_report_list($context) {

    global $DB;

    static $reportlist = null;

    if (!is_null($reportlist)) {

        return $reportlist;

    }

    $reports = $DB->get_records('quiz_reports', null, 'displayorder DESC', 'name, capability');

    $reportdirs = core_component::get_plugin_list('quiz');

    // Order the reports tab in descending order of displayorder.

    $reportcaps = [];

    foreach ($reports as $key => $report) {

        if (array_key_exists($report->name, $reportdirs)) {

            $reportcaps[$report->name] = $report->capability;

        }

    }

    // Add any other reports, which are on disc but not in the DB, on the end.

    foreach ($reportdirs as $reportname => $notused) {

        if (!isset($reportcaps[$reportname])) {

            $reportcaps[$reportname] = null;

        }

    }

    $reportlist = [];

    foreach ($reportcaps as $name => $capability) {

        if (empty($capability)) {

            $capability = 'mod/quiz:viewreports';

        }

        if (has_capability($capability, $context)) {

            $reportlist[] = $name;

        }

    }

    return $reportlist;

}

/**

 * Create a filename for use when downloading data from a quiz report. It is

 * expected that this will be passed to flexible_table::is_downloading, which

 * cleans the filename of bad characters and adds the file extension.

 * @param string $report the type of report.

 * @param string $courseshortname the course shortname.

 * @param string $quizname the quiz name.

 * @return string the filename.

 */

function quiz_report_download_filename($report, $courseshortname, $quizname) {

    return $courseshortname . '-' . format_string($quizname, true) . '-' . $report;

}

/**

 * Get the default report for the current user.

 * @param stdClass $context the quiz context.

 */

function quiz_report_default_report($context) {

    $reports = quiz_report_list($context);

    return reset($reports);

}

/**

 * Generate a message saying that this quiz has no questions, with a button to

 * go to the edit page, if the user has the right capability.

 * @param stdClass $quiz the quiz settings.

 * @param stdClass $cm the course_module object.

 * @param stdClass $context the quiz context.

 * @return string HTML to output.

 */

function quiz_no_questions_message($quiz, $cm, $context) {

    global $OUTPUT;

    $output = '';

    $output .= $OUTPUT->notification(get_string('noquestions', 'quiz'));

    if (has_capability('mod/quiz:manage', $context)) {

        $output .= $OUTPUT->single_button(new moodle_url('/mod/quiz/edit.php',

        ['cmid' => $cm->id]), get_string('editquiz', 'quiz'), 'get');

    }

    return $output;

}

/**

 * Should the grades be displayed in this report. That depends on the quiz

 * display options, and whether the quiz is graded.

 * @param stdClass $quiz the quiz settings.

 * @param context $context the quiz context.

 * @return bool

 */

function quiz_report_should_show_grades($quiz, context $context) {

    if ($quiz->timeclose && time() > $quiz->timeclose) {

        $when = display_options::AFTER_CLOSE;

    } else {

        $when = display_options::LATER_WHILE_OPEN;

    }

    $reviewoptions = display_options::make_from_quiz($quiz, $when);

    return quiz_has_grades($quiz) &&

            ($reviewoptions->marks >= question_display_options::MARK_AND_MAX ||

            has_capability('moodle/grade:viewhidden', $context));

}