weekly release 2.6dev
[moodle.git] / question / type / random / questiontype.php
CommitLineData
aeb15530 1<?php
f9b0500f
TH
2// This file is part of Moodle - http://moodle.org/
3//
4// Moodle is free software: you can redistribute it and/or modify
5// it under the terms of the GNU General Public License as published by
6// the Free Software Foundation, either version 3 of the License, or
7// (at your option) any later version.
8//
9// Moodle is distributed in the hope that it will be useful,
10// but WITHOUT ANY WARRANTY; without even the implied warranty of
11// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12// GNU General Public License for more details.
13//
14// You should have received a copy of the GNU General Public License
15// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
16
1976496e 17/**
f9b0500f 18 * Question type class for the random question type.
f34488b2 19 *
7764183a
TH
20 * @package qtype
21 * @subpackage random
22 * @copyright 1999 onwards Martin Dougiamas {@link http://moodle.com}
23 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
f9b0500f
TH
24 */
25
26
a17b297d
TH
27defined('MOODLE_INTERNAL') || die();
28
2779cc7d
TH
29require_once($CFG->dirroot . '/question/type/questiontypebase.php');
30
a17b297d 31
f9b0500f
TH
32/**
33 * The random question type.
34 *
35 * This question type does not have a question definition class, nor any
36 * renderers. When you load a question of this type, it actually loads a
37 * question chosen randomly from a particular category in the question bank.
f34488b2 38 *
7764183a
TH
39 * @copyright 1999 onwards Martin Dougiamas {@link http://moodle.com}
40 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
53a4d39f 41 */
f9b0500f
TH
42class qtype_random extends question_type {
43 /** @var string comma-separated list of qytpe names not to select, can be used in SQL. */
f24493ec 44 protected $excludedqtypes = null;
516cf3eb 45
f9b0500f
TH
46 /** @var string comma-separated list of manually graded qytpe names, can be used in SQL. */
47 protected $manualqtypes = null;
516cf3eb 48
f9b0500f
TH
49 /**
50 * Cache of availabe question ids from a particular category.
51 * @var array two-dimensional array. The first key is a category id, the
52 * second key is wether subcategories should be included.
53 */
54 private $availablequestionsbycategory = array();
516cf3eb 55
f9b0500f 56 public function menu_name() {
8b192edb 57 // Don't include this question type in the 'add new question' menu.
a2156789 58 return false;
59 }
60
f9b0500f 61 public function is_manual_graded() {
f24493ec 62 return true;
63 }
64
f9b0500f
TH
65 public function is_usable_by_random() {
66 return false;
f24493ec 67 }
68
f9b0500f 69 public function is_question_manual_graded($question, $otherquestionsinuse) {
f24493ec 70 global $DB;
71 // We take our best shot at working whether a particular question is manually
72 // graded follows: We look to see if any of the questions that this random
73 // question might select if of a manually graded type. If a category contains
74 // a mixture of manual and non-manual questions, and if all the attempts so
75 // far selected non-manual ones, this will give the wrong answer, but we
76 // don't care. Even so, this is an expensive calculation!
77 $this->init_qtype_lists();
78 if (!$this->manualqtypes) {
79 return false;
80 }
81 if ($question->questiontext) {
82 $categorylist = question_categorylist($question->category);
83 } else {
2daffca5 84 $categorylist = array($question->category);
f24493ec 85 }
2daffca5 86 list($qcsql, $qcparams) = $DB->get_in_or_equal($categorylist);
3d9645ae 87 // TODO use in_or_equal for $otherquestionsinuse and $this->manualqtypes.
f24493ec 88 return $DB->record_exists_select('question',
2daffca5 89 "category $qcsql
f24493ec 90 AND parent = 0
91 AND hidden = 0
92 AND id NOT IN ($otherquestionsinuse)
2daffca5 93 AND qtype IN ($this->manualqtypes)", $qcparams);
f24493ec 94 }
95
f24493ec 96 /**
97 * This method needs to be called before the ->excludedqtypes and
98 * ->manualqtypes fields can be used.
99 */
f9b0500f
TH
100 protected function init_qtype_lists() {
101 if (!is_null($this->excludedqtypes)) {
102 return; // Already done.
103 }
104 $excludedqtypes = array();
105 $manualqtypes = array();
106 foreach (question_bank::get_all_qtypes() as $qtype) {
107 $quotedname = "'" . $qtype->name() . "'";
108 if (!$qtype->is_usable_by_random()) {
109 $excludedqtypes[] = $quotedname;
110 } else if ($qtype->is_manual_graded()) {
111 $manualqtypes[] = $quotedname;
f24493ec 112 }
f24493ec 113 }
f9b0500f
TH
114 $this->excludedqtypes = implode(',', $excludedqtypes);
115 $this->manualqtypes = implode(',', $manualqtypes);
f24493ec 116 }
117
72553162 118 public function display_question_editing_page($mform, $question, $wizardnow) {
fe6ce234 119 global $OUTPUT;
4995b9c1 120 $heading = $this->get_heading(empty($question->id));
72553162 121 echo $OUTPUT->heading_with_help($heading, 'pluginname', $this->plugin_name());
bcc234b0 122 $mform->display();
123 }
124
f9b0500f 125 public function get_question_options($question) {
516cf3eb 126 return true;
127 }
128
f59dba84 129 /**
130 * Random questions always get a question name that is Random (cateogryname).
131 * This function is a centralised place to calculate that, given the category.
59f26004 132 * @param object $category the category this question picks from. (Only ->name is used.)
f7970e3c 133 * @param bool $includesubcategories whether this question also picks from subcategories.
3cac440b 134 * @return string the name this question should have.
f59dba84 135 */
f9b0500f 136 public function question_name($category, $includesubcategories) {
3cac440b 137 if ($includesubcategories) {
138 $string = 'randomqplusname';
139 } else {
140 $string = 'randomqname';
141 }
baf706b5 142 return get_string($string, 'qtype_random', shorten_text($category->name, 100));
f59dba84 143 }
144
f9b0500f 145 protected function set_selected_question_name($question, $randomname) {
0ff4bd08 146 $a = new stdClass();
f9b0500f
TH
147 $a->randomname = $randomname;
148 $a->questionname = $question->name;
149 $question->name = get_string('selectedby', 'qtype_random', $a);
5348b899 150 }
151
a13d4fbd 152 public function save_question($question, $form) {
f9b0500f 153 $form->name = '';
72553162
TH
154 $form->questiontextformat = FORMAT_MOODLE;
155 $form->tags = array();
156
f9b0500f
TH
157 // Name is not a required field for random questions, but
158 // parent::save_question Assumes that it is.
a13d4fbd 159 return parent::save_question($question, $form);
f9b0500f 160 }
24e8b9b6 161
f9b0500f 162 public function save_question_options($question) {
a13d4fbd
TH
163 global $DB;
164
24e8b9b6 165 // No options, as such, but we set the parent field to the question's
166 // own id. Setting the parent field has the effect of hiding this
167 // question in various places.
0ff4bd08 168 $updateobject = new stdClass();
24e8b9b6 169 $updateobject->id = $question->id;
170 $updateobject->parent = $question->id;
171
172 // We also force the question name to be 'Random (categoryname)'.
59f26004
TH
173 $category = $DB->get_record('question_categories',
174 array('id' => $question->category), '*', MUST_EXIST);
3cac440b 175 $updateobject->name = $this->question_name($category, !empty($question->questiontext));
24e8b9b6 176 return $DB->update_record('question', $updateobject);
516cf3eb 177 }
178
339ef4c2 179 /**
180 * Get all the usable questions from a particular question category.
181 *
f7970e3c
TH
182 * @param int $categoryid the id of a question category.
183 * @param bool whether to include questions from subcategories.
59f26004
TH
184 * @param string $questionsinuse comma-separated list of question ids to
185 * exclude from consideration.
339ef4c2 186 * @return array of question records.
187 */
f9b0500f
TH
188 public function get_available_questions_from_category($categoryid, $subcategories) {
189 if (isset($this->availablequestionsbycategory[$categoryid][$subcategories])) {
190 return $this->availablequestionsbycategory[$categoryid][$subcategories];
191 }
192
f24493ec 193 $this->init_qtype_lists();
339ef4c2 194 if ($subcategories) {
f9b0500f 195 $categoryids = question_categorylist($categoryid);
339ef4c2 196 } else {
2daffca5 197 $categoryids = array($categoryid);
516cf3eb 198 }
199
f9b0500f
TH
200 $questionids = question_bank::get_finder()->get_questions_from_categories(
201 $categoryids, 'qtype NOT IN (' . $this->excludedqtypes . ')');
202 $this->availablequestionsbycategory[$categoryid][$subcategories] = $questionids;
203 return $questionids;
516cf3eb 204 }
205
f9b0500f
TH
206 public function make_question($questiondata) {
207 return $this->choose_other_question($questiondata, array());
516cf3eb 208 }
209
f9b0500f
TH
210 /**
211 * Load the definition of another question picked randomly by this question.
212 * @param object $questiondata the data defining a random question.
59f26004
TH
213 * @param array $excludedquestions of question ids. We will no pick any
214 * question whose id is in this list.
215 * @param bool $allowshuffle if false, then any shuffle option on the
216 * selected quetsion is disabled.
f9b0500f
TH
217 * @return question_definition|null the definition of the question that was
218 * selected, or null if no suitable question could be found.
219 */
220 public function choose_other_question($questiondata, $excludedquestions, $allowshuffle = true) {
221 $available = $this->get_available_questions_from_category($questiondata->category,
222 !empty($questiondata->questiontext));
223 shuffle($available);
224
225 foreach ($available as $questionid) {
226 if (in_array($questionid, $excludedquestions)) {
227 continue;
228 }
516cf3eb 229
f9b0500f
TH
230 $question = question_bank::load_question($questionid, $allowshuffle);
231 $this->set_selected_question_name($question, $questiondata->name);
232 return $question;
516cf3eb 233 }
f9b0500f 234 return null;
516cf3eb 235 }
236
c7df5006 237 public function get_random_guess_score($questiondata) {
f9b0500f 238 return null;
516cf3eb 239 }
516cf3eb 240}