first commit

question/bank/previewquestion/classes/form/preview_options_form.php

@@ -0,0 +1,106 @@
+<?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 qbank_previewquestion\form;
+
+defined('MOODLE_INTERNAL') || die();
+
+require_once($CFG->libdir . '/formslib.php');
+
+use moodleform;
+use question_display_options;
+use question_engine;
+use qbank_previewquestion\question_preview_options;
+
+/**
+ * Settings form for the preview options.
+ *
+ * @package    qbank_previewquestion
+ * @copyright  2009 The Open University
+ * @author     2021 Safat Shahin <safatshahin@catalyst-au.net>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class preview_options_form extends moodleform {
+
+    public function definition() {
+        $mform = $this->_form;
+
+        $hiddenorvisible = [
+                question_display_options::HIDDEN => get_string('notshown', 'question'),
+                question_display_options::VISIBLE => get_string('shown', 'question'),
+        ];
+
+        $mform->addElement('header', 'attemptoptionsheader', get_string('previewoptions', 'qbank_previewquestion'));
+        $mform->setExpanded('attemptoptionsheader', false);
+        // Add html element with class to display long text in single line.
+        $mform->addElement('html', \html_writer::div(get_string('theoptionsyouselectonlyaffectthepreview',
+            'qbank_previewquestion'), "col-md-12 row d-flex col-form-label mb-3"));
+        $versions = $this->_customdata['versions'];
+        $versions[question_preview_options::ALWAYS_LATEST] = get_string('alwayslatest', 'qbank_previewquestion');
+        $currentversion = $this->_customdata['restartversion'];
+        $select = $mform->addElement('select', 'restartversion', get_string('questionversion', 'qbank_previewquestion'), $versions);
+        $select->setSelected($currentversion);
+        $behaviours = question_engine::get_behaviour_options(
+                $this->_customdata['quba']->get_preferred_behaviour());
+        $mform->addElement('select', 'behaviour',
+                get_string('howquestionsbehave', 'question'), $behaviours);
+        $mform->addHelpButton('behaviour', 'howquestionsbehave', 'question');
+
+        $mform->addElement('float', 'maxmark', get_string('markedoutof', 'question'), ['size' => '5']);
+
+        if ($this->_customdata['maxvariant'] > 1) {
+            $variants = range(1, $this->_customdata['maxvariant']);
+            $mform->addElement('select', 'variant', get_string('questionvariant', 'question'),
+                    array_combine($variants, $variants));
+        }
+        $mform->setType('variant', PARAM_INT);
+
+        $mform->addElement('submit', 'saverestart',
+                get_string('restartwiththeseoptions', 'question'));
+
+        $mform->addElement('header', 'displayoptionsheader', get_string('displayoptions', 'question'));
+        $mform->setExpanded('displayoptionsheader', false);
+
+        $mform->addElement('select', 'correctness', get_string('whethercorrect', 'question'),
+                $hiddenorvisible);
+
+        $marksoptions = [
+                question_display_options::HIDDEN => get_string('notshown', 'question'),
+                question_display_options::MAX_ONLY => get_string('showmaxmarkonly', 'question'),
+                question_display_options::MARK_AND_MAX => get_string('showmarkandmax', 'question'),
+        ];
+        $mform->addElement('select', 'marks', get_string('marks', 'question'), $marksoptions);
+
+        $mform->addElement('select', 'markdp', get_string('decimalplacesingrades', 'question'),
+                question_engine::get_dp_options());
+
+        $mform->addElement('select', 'feedback',
+                get_string('specificfeedback', 'question'), $hiddenorvisible);
+
+        $mform->addElement('select', 'generalfeedback',
+                get_string('generalfeedback', 'question'), $hiddenorvisible);
+
+        $mform->addElement('select', 'rightanswer',
+                get_string('rightanswer', 'question'), $hiddenorvisible);
+
+        $mform->addElement('select', 'history',
+                get_string('responsehistory', 'question'), $hiddenorvisible);
+
+        $mform->addElement('submit', 'saveupdate',
+                get_string('updatedisplayoptions', 'question'));
+    }
+
+}

question/bank/previewquestion/classes/helper.php

@@ -0,0 +1,339 @@
+<?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 qbank_previewquestion;
+
+defined('MOODLE_INTERNAL') || die();
+
+require_once($CFG->dirroot . '/question/editlib.php');
+
+use action_menu;
+use comment;
+use context_module;
+use context;
+use core\plugininfo\qbank;
+use core_question\local\bank\edit_menu_column;
+use core_question\local\bank\view;
+use core_question\local\bank\question_edit_contexts;
+use moodle_url;
+use question_bank;
+use question_definition;
+use question_display_options;
+use question_engine;
+use stdClass;
+
+/**
+ * Class helper contains all the helper functions.
+ *
+ * @package    qbank_previewquestion
+ * @copyright  2010 The Open University
+ * @author     2021 Safat Shahin <safatshahin@catalyst-au.net>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class helper {
+
+    /**
+     * Called via pluginfile.php -> question_pluginfile to serve files belonging to
+     * a question in a question_attempt when that attempt is a preview.
+     *
+     * @param stdClass $course course settings object
+     * @param stdClass $context context object
+     * @param string $component the name of the component we are serving files for.
+     * @param string $filearea the name of the file area.
+     * @param int $qubaid the question_usage this image belongs to.
+     * @param int $slot the relevant slot within the usage.
+     * @param array $args the remaining bits of the file path.
+     * @param bool $forcedownload whether the user must be forced to download the file.
+     * @param array $fileoptions options for the stored files
+     * @return void false if file not found, does not return if found - justsend the file
+     */
+    public static function question_preview_question_pluginfile($course, $context, $component,
+            $filearea, $qubaid, $slot, $args, $forcedownload, $fileoptions): void {
+        global $USER, $DB, $CFG;
+
+        list($context, $course, $cm) = get_context_info_array($context->id);
+        require_login($course, false, $cm);
+
+        $quba = question_engine::load_questions_usage_by_activity($qubaid);
+
+        if (!question_has_capability_on($quba->get_question($slot, false), 'use')) {
+            send_file_not_found();
+        }
+
+        $options = new question_display_options();
+        $options->feedback = question_display_options::VISIBLE;
+        $options->numpartscorrect = question_display_options::VISIBLE;
+        $options->generalfeedback = question_display_options::VISIBLE;
+        $options->rightanswer = question_display_options::VISIBLE;
+        $options->manualcomment = question_display_options::VISIBLE;
+        $options->history = question_display_options::VISIBLE;
+        if (!$quba->check_file_access($slot, $options, $component,
+                $filearea, $args, $forcedownload)) {
+            send_file_not_found();
+        }
+
+        $fs = get_file_storage();
+        $relativepath = implode('/', $args);
+        $fullpath = "/{$context->id}/{$component}/{$filearea}/{$relativepath}";
+        if (!$file = $fs->get_file_by_hash(sha1($fullpath)) or $file->is_directory()) {
+            send_file_not_found();
+        }
+
+        send_stored_file($file, 0, 0, $forcedownload, $fileoptions);
+    }
+
+    /**
+     * The the URL to use for actions relating to this preview.
+     *
+     * @param int $questionid the question being previewed
+     * @param int $qubaid the id of the question usage for this preview
+     * @param question_preview_options $options the options in use
+     * @param context $context context for the question preview
+     * @param moodle_url $returnurl url of the page to return to
+     * @param int|null $restartversion version of the question to use when next restarting the preview.
+     * @return moodle_url
+     */
+    public static function question_preview_action_url($questionid, $qubaid,
+            question_preview_options $options, $context, $returnurl = null, $restartversion = null): moodle_url {
+        $params = [
+                'id' => $questionid,
+                'previewid' => $qubaid,
+        ];
+        if ($context->contextlevel == CONTEXT_MODULE) {
+            $params['cmid'] = $context->instanceid;
+        } else if ($context->contextlevel == CONTEXT_COURSE) {
+            $params['courseid'] = $context->instanceid;
+        }
+        if ($returnurl !== null) {
+            $params['returnurl'] = $returnurl;
+        }
+        if ($restartversion !== null) {
+            $params['restartversion'] = $restartversion;
+        }
+        $params = array_merge($params, $options->get_url_params());
+        return new moodle_url('/question/bank/previewquestion/preview.php', $params);
+    }
+
+    /**
+     * The the URL to use for actions relating to this preview.
+     *
+     * @param int $questionid the question being previewed
+     * @param context $context the current moodle context
+     * @param int $previewid optional previewid to sign post saved previewed answers
+     * @param moodle_url $returnurl url of the page to return to
+     * @return moodle_url
+     */
+    public static function question_preview_form_url($questionid, $context, $previewid = null, $returnurl = null): moodle_url {
+        $params = [
+                'id' => $questionid,
+        ];
+        if ($context->contextlevel == CONTEXT_MODULE) {
+            $params['cmid'] = $context->instanceid;
+        } else if ($context->contextlevel == CONTEXT_COURSE) {
+            $params['courseid'] = $context->instanceid;
+        }
+        if ($previewid) {
+            $params['previewid'] = $previewid;
+        }
+        if ($returnurl !== null) {
+            $params['returnurl'] = $returnurl;
+        }
+        return new moodle_url('/question/bank/previewquestion/preview.php', $params);
+    }
+
+    /**
+     * Delete the current preview, if any, and redirect to start a new preview.
+     *
+     * @param int $previewid id of the preview while restarting it
+     * @param int $questionid id of the question in preview
+     * @param object $displayoptions display options for the question in preview
+     * @param object $context context of the question for preview
+     * @param moodle_url $returnurl url of the page to return to
+     * @param int|null $restartversion version of the question to use when next restarting the preview.
+     * @return void
+     */
+    public static function restart_preview($previewid, $questionid, $displayoptions, $context,
+        $returnurl = null, $restartversion = null): void {
+        global $DB;
+
+        if ($previewid) {
+            $transaction = $DB->start_delegated_transaction();
+            question_engine::delete_questions_usage_by_activity($previewid);
+            $transaction->allow_commit();
+        }
+        redirect(self::question_preview_url($questionid, $displayoptions->behaviour,
+                $displayoptions->maxmark, $displayoptions, $displayoptions->variant,
+                $context, $returnurl, $restartversion));
+    }
+
+    /**
+     * Generate the URL for starting a new preview of a given question with the given options.
+     *
+     * @param integer $questionid the question to preview
+     * @param string $preferredbehaviour the behaviour to use for the preview
+     * @param float $maxmark the maximum to mark the question out of
+     * @param question_display_options $displayoptions the display options to use
+     * @param int $variant the variant of the question to preview. If null, one will
+     *      be picked randomly
+     * @param object $context context to run the preview in (affects things like
+     *      filter settings, theme, lang, etc.) Defaults to $PAGE->context
+     * @param moodle_url $returnurl url of the page to return to
+     * @param int $restartversion The version of the question to use when restarting the preview.
+     * @return moodle_url the URL
+     */
+    public static function question_preview_url($questionid, $preferredbehaviour = null,
+            $maxmark = null, $displayoptions = null, $variant = null, $context = null, $returnurl = null,
+            $restartversion = null): moodle_url {
+
+        $params = ['id' => $questionid];
+
+        if (!is_null($restartversion)) {
+            $params['restartversion'] = $restartversion;
+        }
+        if (is_null($context)) {
+            global $PAGE;
+            $context = $PAGE->context;
+        }
+        if ($context->contextlevel == CONTEXT_MODULE) {
+            $params['cmid'] = $context->instanceid;
+        } else if ($context->contextlevel == CONTEXT_COURSE) {
+            $params['courseid'] = $context->instanceid;
+        }
+
+        if (!is_null($preferredbehaviour)) {
+            $params['behaviour'] = $preferredbehaviour;
+        }
+
+        if (!is_null($maxmark)) {
+            $params['maxmark'] = format_float($maxmark, -1);
+        }
+
+        if (!is_null($displayoptions)) {
+            $params['correctness']     = $displayoptions->correctness;
+            $params['marks']           = $displayoptions->marks;
+            $params['markdp']          = $displayoptions->markdp;
+            $params['feedback']        = (bool) $displayoptions->feedback;
+            $params['generalfeedback'] = (bool) $displayoptions->generalfeedback;
+            $params['rightanswer']     = (bool) $displayoptions->rightanswer;
+            $params['history']         = (bool) $displayoptions->history;
+        }
+
+        if (!is_null($returnurl)) {
+            $params['returnurl'] = $returnurl;
+        }
+
+        if ($variant) {
+            $params['variant'] = $variant;
+        }
+
+        return new moodle_url('/question/bank/previewquestion/preview.php', $params);
+    }
+
+    /**
+     * Popup params for the question preview.
+     *
+     * @return array that can be passed as $params to the {@see popup_action} constructor.
+     */
+    public static function question_preview_popup_params(): array {
+        return [
+                'height' => 600,
+                'width' => 800,
+        ];
+    }
+
+    /**
+     * Get the extra elements for preview from qbank plugins.
+     *
+     * @param  question_definition $question question definition object
+     * @param  int $courseid id of the course
+     * @return array
+     */
+    public static function get_preview_extra_elements(question_definition $question, int $courseid): array {
+        $plugins = get_plugin_list_with_function('qbank', 'preview_display');
+
+        $comment = '';
+        $extrahtml = [];
+        foreach ($plugins as $componentname => $plugin) {
+            $pluginhtml = component_callback($componentname, 'preview_display', [$question, $courseid]);
+            if ($componentname === 'qbank_comment') {
+                $comment = $pluginhtml;
+                continue;
+            }
+            $extrahtml[] = $pluginhtml;
+        }
+        return [$comment, $extrahtml];
+    }
+
+    /**
+     * Checks if question is the latest version.
+     *
+     * @param string $version Question version to check
+     * @param string $questionbankentryid Entry to check against
+     * @return bool
+     */
+    public static function is_latest(string $version, string $questionbankentryid): bool {
+        global $DB;
+
+        $sql = 'SELECT MAX(version) AS max
+                  FROM {question_versions}
+                 WHERE questionbankentryid = ?';
+        $latestversion = $DB->get_record_sql($sql, [$questionbankentryid]);
+
+        if (isset($latestversion->max)) {
+            return ($version === $latestversion->max) ? true : false;
+        }
+        return false;
+    }
+
+    /**
+     * Loads question version ids for current question.
+     *
+     * @param  string $questionbankentryid Question bank entry id
+     * @return array  $questionids Array containing question id as key and version as value.
+     */
+    public static function load_versions(string $questionbankentryid): array {
+        global $DB;
+
+        $questionids = [];
+        $sql = 'SELECT version, questionid
+                  FROM {question_versions}
+                 WHERE questionbankentryid = ?
+              ORDER BY version';
+
+        $versions = $DB->get_records_sql($sql, [$questionbankentryid]);
+        foreach ($versions as $key => $version) {
+            $questionids[$version->questionid] = $key;
+        }
+        return $questionids;
+    }
+
+    /**
+     * Return the question ID from the array of id => version that corresponds to the requested version.
+     *
+     * If the requested version is question_preview_options::ALWAYS_LATEST, this will return the latest version.
+     *
+     * @param array $versions
+     * @param int $restartversion
+     * @return ?int
+     */
+    public static function get_restart_id(array $versions, int $restartversion): ?int {
+        if ($restartversion === question_preview_options::ALWAYS_LATEST) {
+            return array_key_last($versions);
+        } else {
+            return array_search($restartversion, $versions) ?: null;
+        }
+    }
+}

question/bank/previewquestion/classes/output/renderer.php

@@ -0,0 +1,70 @@
+<?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 qbank_previewquestion\output;
+
+use context;
+use qbank_previewquestion\helper;
+use qbank_previewquestion\question_preview_options;
+
+/**
+ * Class renderer for rendering preview url
+ *
+ * @package    qbank_previewquestion
+ * @copyright  2009 The Open University
+ * @author     2021 Safat Shahin <safatshahin@catalyst-au.net>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class renderer extends \plugin_renderer_base {
+
+    /**
+     * Render an icon, optionally with the word 'Preview' beside it, to preview a given question.
+     *
+     * @param int $questionid the id of the question to be previewed.
+     * @param context $context the context in which the preview is happening.
+     *      Must be a course or category context.
+     * @param bool $showlabel if true, show the word 'Preview' after the icon.
+     *      If false, just show the icon.
+     */
+    public function question_preview_link($questionid, context $context, $showlabel) {
+        if ($showlabel) {
+            $alt = '';
+            $label = get_string('preview');
+            $attributes = [];
+        } else {
+            $alt = get_string('preview');
+            $label = '';
+            $attributes = ['title' => $alt];
+        }
+
+        $image = $this->pix_icon('t/preview', $alt, '', ['class' => 'iconsmall']);
+        $link = helper::question_preview_url($questionid, null, null, null, null, $context, null,
+                question_preview_options::ALWAYS_LATEST);
+        $action = new \popup_action('click', $link, 'questionpreview', helper::question_preview_popup_params());
+
+        return $this->action_link($link, $image . $label, $action, $attributes);
+    }
+
+    /**
+     * Render the preview page.
+     *
+     * @param array $previewdata
+     */
+    public function render_preview_page($previewdata) {
+        return $this->render_from_template('qbank_previewquestion/preview_question', $previewdata);
+    }
+
+}

question/bank/previewquestion/classes/plugin_feature.php

@@ -0,0 +1,34 @@
+<?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 qbank_previewquestion;
+
+/**
+ * Class columns is the entrypoint for the columns.
+ *
+ * @package    qbank_previewquestion
+ * @copyright  2021 Catalyst IT Australia Pty Ltd
+ * @author     Safat Shahin <safatshahin@catalyst-au.net>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class plugin_feature extends \core_question\local\bank\plugin_features_base{
+
+    public function get_question_actions($qbank): array {
+        return [
+            new preview_action($qbank)
+        ];
+    }
+}

question/bank/previewquestion/classes/preview_action.php

@@ -0,0 +1,69 @@
+<?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 qbank_previewquestion;
+
+use core_question\local\bank\question_action_base;
+
+/**
+ * Question bank columns for the preview action icon.
+ *
+ * @package   qbank_previewquestion
+ * @copyright 2009 Tim Hunt
+ * @author    2021 Safat Shahin <safatshahin@catalyst-au.net>
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class preview_action extends question_action_base {
+
+    /**
+     * @var string store this lang string for performance.
+     */
+    protected $strpreview;
+
+    public function init(): void {
+        parent::init();
+        $this->strpreview = get_string('preview');
+    }
+
+    public function get_menu_position(): int {
+        return 100;
+    }
+
+    protected function get_url_icon_and_label(\stdClass $question): array {
+        if (!\question_bank::is_qtype_installed($question->qtype)) {
+            // It sometimes happens that people end up with junk questions
+            // in their question bank of a type that is no longer installed.
+            // We cannot do most actions on them, because that leads to errors.
+            return [null, null, null];
+        }
+
+        if (question_has_capability_on($question, 'use')) {
+            $context = $this->qbank->get_most_specific_context();
+            // Default previews to always use the latest question version, unless we are previewing specific versions from the
+            // question history.
+            if ($this->qbank->is_listing_specific_versions()) {
+                $requestedversion = $question->version;
+            } else {
+                $requestedversion = question_preview_options::ALWAYS_LATEST;
+            }
+            $url = helper::question_preview_url($question->id, null, null,
+                                                    null, null, $context, $this->qbank->returnurl, $requestedversion);
+            return [$url, 't/preview', $this->strpreview];
+        } else {
+            return [null, null, null];
+        }
+    }
+}

question/bank/previewquestion/classes/privacy/provider.php

@@ -0,0 +1,32 @@
+<?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 qbank_previewquestion\privacy;
+
+/**
+ * Privacy Subsystem for qbank_previewquestion implementing null_provider.
+ *
+ * @package    qbank_previewquestion
+ * @copyright  2021 Catalyst IT Australia Pty Ltd
+ * @author     Safat Shahin <safatshahin@catalyst-au.net>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class provider implements \core_privacy\local\metadata\null_provider {
+
+    public static function get_reason(): string {
+        return 'privacy:metadata';
+    }
+}

question/bank/previewquestion/classes/question_preview_options.php

@@ -0,0 +1,144 @@
+<?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 qbank_previewquestion;
+
+use question_display_options;
+
+/**
+ * Displays question preview options as default and set the options.
+ *
+ * Setting default, getting and setting user preferences in question preview options.
+ *
+ * @package    qbank_previewquestion
+ * @copyright  2010 The Open University
+ * @author     2021 Safat Shahin <safatshahin@catalyst-au.net>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class question_preview_options extends question_display_options {
+
+    /** @var string the behaviour to use for this preview. */
+    public $behaviour;
+
+    /** @var number the maximum mark to use for this preview. */
+    public $maxmark;
+
+    /** @var int the variant of the question to preview. */
+    public $variant;
+
+    /** @var string prefix to append to field names to get user_preference names. */
+    const OPTIONPREFIX = 'question_preview_options_';
+
+    /** @var int Special value for question version ID to indicate that we should always use the latest version */
+    const ALWAYS_LATEST = 0;
+
+    /**
+     * Constructor.
+     * @param \stdClass $question
+     */
+    public function __construct($question) {
+        $this->behaviour = 'deferredfeedback';
+        $this->maxmark = $question->defaultmark;
+        $this->variant = null;
+        $this->correctness = self::VISIBLE;
+        $this->marks = self::MARK_AND_MAX;
+        $this->markdp = get_config('quiz', 'decimalpoints');
+        $this->feedback = self::VISIBLE;
+        $this->numpartscorrect = $this->feedback;
+        $this->generalfeedback = self::VISIBLE;
+        $this->rightanswer = self::VISIBLE;
+        $this->history = self::HIDDEN;
+        $this->flags = self::HIDDEN;
+        $this->manualcomment = self::HIDDEN;
+    }
+
+    /**
+     * Names of the options we store in the user preferences table.
+     * @return array
+     */
+    protected function get_user_pref_fields(): array {
+        return ['behaviour', 'correctness', 'marks', 'markdp', 'feedback', 'generalfeedback', 'rightanswer', 'history'];
+    }
+
+    /**
+     * Names and param types of the options we read from the request.
+     * @return array
+     */
+    protected function get_field_types(): array {
+        return [
+                'behaviour' => PARAM_ALPHA,
+                'maxmark' => PARAM_LOCALISEDFLOAT,
+                'variant' => PARAM_INT,
+                'correctness' => PARAM_BOOL,
+                'marks' => PARAM_INT,
+                'markdp' => PARAM_INT,
+                'feedback' => PARAM_BOOL,
+                'generalfeedback' => PARAM_BOOL,
+                'rightanswer' => PARAM_BOOL,
+                'history' => PARAM_BOOL,
+        ];
+    }
+
+    /**
+     * Load the value of the options from the user_preferences table.
+     */
+    public function load_user_defaults(): void {
+        $defaults = get_config('question_preview');
+        foreach ($this->get_user_pref_fields() as $field) {
+            $this->$field = get_user_preferences(
+                    self::OPTIONPREFIX . $field, $defaults->$field);
+        }
+        $this->numpartscorrect = $this->feedback;
+    }
+
+    /**
+     * Save a change to the user's preview options to the database.
+     * @param object $newoptions
+     */
+    public function save_user_preview_options($newoptions): void {
+        foreach ($this->get_user_pref_fields() as $field) {
+            if (isset($newoptions->$field)) {
+                set_user_preference(self::OPTIONPREFIX . $field, $newoptions->$field);
+            }
+        }
+    }
+
+    /**
+     * Set the value of any fields included in the request.
+     */
+    public function set_from_request(): void {
+        foreach ($this->get_field_types() as $field => $type) {
+            $this->$field = optional_param($field, $this->$field, $type);
+        }
+        $this->numpartscorrect = $this->feedback;
+    }
+
+    /**
+     * Parameters needed in the URL when continuing this preview.
+     *
+     * @return array URL fragment.
+     */
+    public function get_url_params(): array {
+        $params = [];
+        foreach ($this->get_field_types() as $field => $notused) {
+            if ($field === 'behaviour' || $field === 'maxmark' || is_null($this->$field)) {
+                continue;
+            }
+            $params[$field] = $this->$field;
+        }
+        return $params;
+    }
+}