C:/xampp/htdocs/moodle/question/engine/bank.php

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<?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/>.

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

require_once(dirname(__FILE__) . '/../type/questiontypebase.php');


abstract class question_bank {
    // TODO: This limit can be deleted if someday we move all TEXTS to BIG ones. MDL-19603
    const MAX_SUMMARY_LENGTH = 32000;

    private static $questiontypes = array();

    private static $loadedqdefs = array();

    protected static $questionfinder = null;

    private static $testmode = false;
    private static $testdata = array();

    private static $questionconfig = null;

    private static $fractionoptions = null;
    private static $fractionoptionsfull = null;

    public static function is_qtype_installed($qtypename) {
        $plugindir = get_plugin_directory('qtype', $qtypename);
        return $plugindir && is_readable($plugindir . '/questiontype.php');
    }

    public static function get_qtype($qtypename, $mustexist = true) {
        global $CFG;
        if (isset(self::$questiontypes[$qtypename])) {
            return self::$questiontypes[$qtypename];
        }
        $file = get_plugin_directory('qtype', $qtypename) . '/questiontype.php';
        if (!is_readable($file)) {
            if ($mustexist || $qtypename == 'missingtype') {
                throw new coding_exception('Unknown question type ' . $qtypename);
            } else {
                return self::get_qtype('missingtype');
            }
        }
        include_once($file);
        $class = 'qtype_' . $qtypename;
        if (!class_exists($class)) {
            throw new coding_exception("Class $class must be defined in $file");
        }
        self::$questiontypes[$qtypename] = new $class();
        return self::$questiontypes[$qtypename];
    }

    public static function get_config() {
        if (is_null(self::$questionconfig)) {
            self::$questionconfig = get_config('question');
        }
        return self::$questionconfig;
    }

    public static function qtype_enabled($qtypename) {
        $config = self::get_config();
        $enabledvar = $qtypename . '_disabled';
        return self::qtype_exists($qtypename) && empty($config->$enabledvar) &&
                self::get_qtype($qtypename)->menu_name() != '';
    }

    public static function qtype_exists($qtypename) {
        return array_key_exists($qtypename, get_plugin_list('qtype'));
    }

    public static function get_qtype_name($qtypename) {
        return self::get_qtype($qtypename)->local_name();
    }

    public static function get_all_qtypes() {
        $qtypes = array();
        foreach (get_plugin_list('qtype') as $plugin => $notused) {
            try {
                $qtypes[$plugin] = self::get_qtype($plugin);
            } catch (coding_exception $e) {
                // Catching coding_exceptions here means that incompatible
                // question types do not cause the rest of Moodle to break.
            }
        }
        return $qtypes;
    }

    public static function sort_qtype_array($qtypes, $config = null) {
        if (is_null($config)) {
            $config = self::get_config();
        }

        $sortorder = array();
        $otherqtypes = array();
        foreach ($qtypes as $name => $localname) {
            $sortvar = $name . '_sortorder';
            if (isset($config->$sortvar)) {
                $sortorder[$config->$sortvar] = $name;
            } else {
                $otherqtypes[$name] = $localname;
            }
        }

        ksort($sortorder);
        collatorlib::asort($otherqtypes);

        $sortedqtypes = array();
        foreach ($sortorder as $name) {
            $sortedqtypes[$name] = $qtypes[$name];
        }
        foreach ($otherqtypes as $name => $notused) {
            $sortedqtypes[$name] = $qtypes[$name];
        }
        return $sortedqtypes;
    }

    public static function get_creatable_qtypes() {
        $config = self::get_config();
        $allqtypes = self::get_all_qtypes();

        $qtypenames = array();
        foreach ($allqtypes as $name => $qtype) {
            if (self::qtype_enabled($name)) {
                $qtypenames[$name] = $qtype->local_name();
            }
        }

        $qtypenames = self::sort_qtype_array($qtypenames);

        $creatableqtypes = array();
        foreach ($qtypenames as $name => $notused) {
            $creatableqtypes[$name] = $allqtypes[$name];
        }
        return $creatableqtypes;
    }

    public static function load_question_definition_classes($qtypename) {
        global $CFG;
        if (isset(self::$loadedqdefs[$qtypename])) {
            return;
        }
        $file = $CFG->dirroot . '/question/type/' . $qtypename . '/question.php';
        if (!is_readable($file)) {
            throw new coding_exception('Unknown question type (no definition) ' . $qtypename);
        }
        include_once($file);
        self::$loadedqdefs[$qtypename] = 1;
    }

    public static function load_question($questionid, $allowshuffle = true) {
        global $DB;

        if (self::$testmode) {
            // Evil, test code in production, but now way round it.
            return self::return_test_question_data($questionid);
        }

        $questiondata = $DB->get_record_sql('
                SELECT q.*, qc.contextid
                FROM {question} q
                JOIN {question_categories} qc ON q.category = qc.id
                WHERE q.id = :id', array('id' => $questionid), MUST_EXIST);
        get_question_options($questiondata);
        if (!$allowshuffle) {
            $questiondata->options->shuffleanswers = false;
        }
        return self::make_question($questiondata);
    }

    public static function make_question($questiondata) {
        return self::get_qtype($questiondata->qtype, false)->make_question($questiondata, false);
    }

    public static function get_finder() {
        if (is_null(self::$questionfinder)) {
            self::$questionfinder = new question_finder();
        }
        return self::$questionfinder;
    }

    public static function start_unit_test() {
        self::$testmode = true;
    }

    public static function end_unit_test() {
        self::$testmode = false;
        self::$testdata = array();
    }

    private static function return_test_question_data($questionid) {
        if (!isset(self::$testdata[$questionid])) {
            throw new coding_exception('question_bank::return_test_data(' . $questionid .
                    ') called, but no matching question has been loaded by load_test_data.');
        }
        return self::$testdata[$questionid];
    }

    public static function load_test_question_data(question_definition $question) {
        if (!self::$testmode) {
            throw new coding_exception('question_bank::load_test_data called when ' .
                    'not in test mode.');
        }
        self::$testdata[$question->id] = $question;
    }

    protected function ensure_fraction_options_initialised() {
        if (!is_null(self::$fractionoptions)) {
            return;
        }

        // define basic array of grades. This list comprises all fractions of the form:
        // a. p/q for q <= 6, 0 <= p <= q
        // b. p/10 for 0 <= p <= 10
        // c. 1/q for 1 <= q <= 10
        // d. 1/20
        $rawfractions = array(
            0.9000000,
            0.8333333,
            0.8000000,
            0.7500000,
            0.7000000,
            0.6666667,
            0.6000000,
            0.5000000,
            0.4000000,
            0.3333333,
            0.3000000,
            0.2500000,
            0.2000000,
            0.1666667,
            0.1428571,
            0.1250000,
            0.1111111,
            0.1000000,
            0.0500000,
        );

        // Put the None option at the top.
        self::$fractionoptions = array(
            '0.0' => get_string('none'),
            '1.0' => '100%',
        );
        self::$fractionoptionsfull = array(
            '0.0' => get_string('none'),
            '1.0' => '100%',
        );

        // The the positive grades in descending order.
        foreach ($rawfractions as $fraction) {
            $percentage = (100 * $fraction) . '%';
            self::$fractionoptions["$fraction"] = $percentage;
            self::$fractionoptionsfull["$fraction"] = $percentage;
        }

        // The the negative grades in descending order.
        foreach (array_reverse($rawfractions) as $fraction) {
            self::$fractionoptionsfull['' . (-$fraction)] = (-100 * $fraction) . '%';
        }

        self::$fractionoptionsfull['-1.0'] = '-100%';
    }

    public static function fraction_options() {
        self::ensure_fraction_options_initialised();
        return self::$fractionoptions;
    }

    public static function fraction_options_full() {
        self::ensure_fraction_options_initialised();
        return self::$fractionoptionsfull;
    }
}


class question_finder {
    public function get_questions_from_categories($categoryids, $extraconditions,
            $extraparams = array()) {
        global $DB;

        list($qcsql, $qcparams) = $DB->get_in_or_equal($categoryids, SQL_PARAMS_NAMED, 'qc');

        if ($extraconditions) {
            $extraconditions = ' AND (' . $extraconditions . ')';
        }

        return $DB->get_records_select_menu('question',
                "category $qcsql
                 AND parent = 0
                 AND hidden = 0
                 $extraconditions", $qcparams + $extraparams, '', 'id,id AS id2');
    }
}