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d1b7e03d TH |
1 | <?php |
2 | ||
3 | // This file is part of Moodle - http://moodle.org/ | |
4 | // | |
5 | // Moodle is free software: you can redistribute it and/or modify | |
6 | // it under the terms of the GNU General Public License as published by | |
7 | // the Free Software Foundation, either version 3 of the License, or | |
8 | // (at your option) any later version. | |
9 | // | |
10 | // Moodle is distributed in the hope that it will be useful, | |
11 | // but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | // GNU General Public License for more details. | |
14 | // | |
15 | // You should have received a copy of the GNU General Public License | |
16 | // along with Moodle. If not, see <http://www.gnu.org/licenses/>. | |
17 | ||
18 | ||
19 | /** | |
20 | * More object oriented wrappers around parts of the Moodle question bank. | |
21 | * | |
22 | * In due course, I expect that the question bank will be converted to a | |
23 | * fully object oriented structure, at which point this file can be a | |
24 | * starting point. | |
25 | * | |
26 | * @package moodlecore | |
27 | * @subpackage questionbank | |
28 | * @copyright 2009 The Open University | |
29 | * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later | |
30 | */ | |
31 | ||
32 | ||
33 | /** | |
34 | * This static class provides access to the other question bank. | |
35 | * | |
36 | * It provides functions for managing question types and question definitions. | |
37 | * | |
38 | * @copyright 2009 The Open University | |
39 | * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later | |
40 | */ | |
41 | abstract class question_bank { | |
42 | /** @var array question type name => question_type subclass. */ | |
43 | private static $questiontypes = array(); | |
44 | ||
45 | /** @var array question type name => 1. Records which question definitions have been loaded. */ | |
46 | private static $loadedqdefs = array(); | |
47 | ||
48 | protected static $questionfinder = null; | |
49 | ||
50 | /** @var boolean nasty hack to allow unit tests to call {@link load_question()}. */ | |
51 | private static $testmode = false; | |
52 | private static $testdata = array(); | |
53 | ||
54 | /** | |
55 | * Get the question type class for a particular question type. | |
56 | * @param string $qtypename the question type name. For example 'multichoice' or 'shortanswer'. | |
57 | * @param boolean $mustexist if false, the missing question type is returned when | |
58 | * the requested question type is not installed. | |
59 | * @return question_type the corresponding question type class. | |
60 | */ | |
61 | public static function get_qtype($qtypename, $mustexist = true) { | |
62 | global $CFG; | |
63 | if (isset(self::$questiontypes[$qtypename])) { | |
64 | return self::$questiontypes[$qtypename]; | |
65 | } | |
f29aeb5a | 66 | $file = get_plugin_directory('qtype', $qtypename) . '/questiontype.php'; |
d1b7e03d TH |
67 | if (!is_readable($file)) { |
68 | if ($mustexist || $qtypename == 'missingtype') { | |
69 | throw new Exception('Unknown question type ' . $qtypename); | |
70 | } else { | |
71 | return self::get_qtype('missingtype'); | |
72 | } | |
73 | } | |
74 | include_once($file); | |
75 | $class = 'qtype_' . $qtypename; | |
f29aeb5a TH |
76 | if (!class_exists($class)) { |
77 | throw new coding_exception("Class $class must be defined in $file"); | |
78 | } | |
d1b7e03d TH |
79 | self::$questiontypes[$qtypename] = new $class(); |
80 | return self::$questiontypes[$qtypename]; | |
81 | } | |
82 | ||
06f8ed54 TH |
83 | /** |
84 | * @param string $qtypename the internal name of a question type. For example multichoice. | |
85 | * @return boolean whether users are allowed to create questions of this type. | |
86 | */ | |
87 | public static function qtype_enabled($qtypename) { | |
f29aeb5a | 88 | return true; // TODO |
06f8ed54 TH |
89 | } |
90 | ||
d1b7e03d TH |
91 | /** |
92 | * @param $qtypename the internal name of a question type, for example multichoice. | |
93 | * @return string the human_readable name of this question type, from the language pack. | |
94 | */ | |
95 | public static function get_qtype_name($qtypename) { | |
96 | return self::get_qtype($qtypename)->menu_name(); | |
97 | } | |
98 | ||
99 | /** | |
100 | * @return array all the installed question types. | |
101 | */ | |
102 | public static function get_all_qtypes() { | |
103 | $qtypes = array(); | |
f29aeb5a TH |
104 | foreach (get_plugin_list('qtype') as $plugin => $notused) { |
105 | try { | |
106 | $qtypes[$plugin] = self::get_qtype($plugin); | |
107 | } catch (Exception $e) { | |
108 | // TODO ingore, but reivew this later. | |
109 | } | |
d1b7e03d TH |
110 | } |
111 | return $qtypes; | |
112 | } | |
113 | ||
114 | /** | |
115 | * Load the question definition class(es) belonging to a question type. That is, | |
116 | * include_once('/question/type/' . $qtypename . '/question.php'), with a bit | |
117 | * of checking. | |
118 | * @param string $qtypename the question type name. For example 'multichoice' or 'shortanswer'. | |
119 | */ | |
120 | public static function load_question_definition_classes($qtypename) { | |
121 | global $CFG; | |
122 | if (isset(self::$loadedqdefs[$qtypename])) { | |
123 | return; | |
124 | } | |
125 | $file = $CFG->dirroot . '/question/type/' . $qtypename . '/question.php'; | |
126 | if (!is_readable($file)) { | |
127 | throw new Exception('Unknown question type (no definition) ' . $qtypename); | |
128 | } | |
129 | include_once($file); | |
130 | self::$loadedqdefs[$qtypename] = 1; | |
131 | } | |
132 | ||
133 | /** | |
134 | * Load a question definition from the database. The object returned | |
135 | * will actually be of an appropriate {@link question_definition} subclass. | |
136 | * @param integer $questionid the id of the question to load. | |
a31689a4 | 137 | * @param boolean $allowshuffle if false, then any shuffle option on the selected quetsion is disabled. |
d1b7e03d TH |
138 | * @return question_definition loaded from the database. |
139 | */ | |
a31689a4 | 140 | public static function load_question($questionid, $allowshuffle = true) { |
c76145d3 TH |
141 | global $DB; |
142 | ||
d1b7e03d TH |
143 | if (self::$testmode) { |
144 | // Evil, test code in production, but now way round it. | |
145 | return self::return_test_question_data($questionid); | |
146 | } | |
147 | ||
56e82d99 TH |
148 | $questiondata = $DB->get_record_sql(' |
149 | SELECT q.*, qc.contextid | |
150 | FROM {question} q | |
151 | JOIN {question_categories} qc ON q.category = qc.id | |
152 | WHERE q.id = :id', array('id' => $questionid), MUST_EXIST); | |
d1b7e03d | 153 | get_question_options($questiondata); |
a31689a4 TH |
154 | if (!$allowshuffle) { |
155 | $questiondata->options->shuffleanswers = false; | |
156 | } | |
d1b7e03d TH |
157 | return self::make_question($questiondata); |
158 | } | |
159 | ||
160 | /** | |
161 | * Convert the question information loaded with {@link get_question_options()} | |
162 | * to a question_definintion object. | |
163 | * @param object $questiondata raw data loaded from the database. | |
164 | * @return question_definition loaded from the database. | |
165 | */ | |
166 | public static function make_question($questiondata) { | |
167 | return self::get_qtype($questiondata->qtype, false)->make_question($questiondata, false); | |
168 | } | |
169 | ||
170 | /** | |
171 | * @return question_finder a question finder. | |
172 | */ | |
173 | public static function get_finder() { | |
174 | if (is_null(self::$questionfinder)) { | |
175 | self::$questionfinder = new question_finder(); | |
176 | } | |
177 | return self::$questionfinder; | |
178 | } | |
179 | ||
180 | /** | |
181 | * Only to be called from unit tests. Allows {@link load_test_data()} to be used. | |
182 | */ | |
183 | public static function start_unit_test() { | |
184 | self::$testmode = true; | |
185 | } | |
186 | ||
187 | /** | |
188 | * Only to be called from unit tests. Allows {@link load_test_data()} to be used. | |
189 | */ | |
190 | public static function end_unit_test() { | |
191 | self::$testmode = false; | |
192 | self::$testdata = array(); | |
193 | } | |
194 | ||
195 | private static function return_test_question_data($questionid) { | |
196 | if (!isset(self::$testdata[$questionid])) { | |
197 | throw new Exception('question_bank::return_test_data(' . $questionid . | |
198 | ') called, but no matching question has been loaded by load_test_data.'); | |
199 | } | |
200 | return self::$testdata[$questionid]; | |
201 | } | |
202 | ||
203 | /** | |
204 | * To be used for unit testing only. Will throw an exception if | |
205 | * {@link start_unit_test()} has not been called first. | |
206 | * @param object $questiondata a question data object to put in the test data store. | |
207 | */ | |
208 | public static function load_test_question_data(question_definition $question) { | |
209 | if (!self::$testmode) { | |
210 | throw new Exception('question_bank::load_test_data called when not in test mode.'); | |
211 | } | |
212 | self::$testdata[$question->id] = $question; | |
213 | } | |
214 | } | |
215 | ||
216 | class question_finder { | |
217 | /** | |
218 | * Get the ids of all the questions in a list of categoryies. | |
219 | * @param integer|string|array $categoryids either a categoryid, or a comma-separated list | |
220 | * category ids, or an array of them. | |
221 | * @param string $extraconditions extra conditions to AND with the rest of the where clause. | |
222 | * @return array questionid => questionid. | |
223 | */ | |
224 | public function get_questions_from_categories($categoryids, $extraconditions) { | |
225 | if (is_array($categoryids)) { | |
226 | $categoryids = implode(',', $categoryids); | |
227 | } | |
228 | ||
229 | if ($extraconditions) { | |
230 | $extraconditions = ' AND (' . $extraconditions . ')'; | |
231 | } | |
c76145d3 TH |
232 | // TODO switch to using $DB->in_or_equal. |
233 | $questionids = $DB->get_records_select_menu('question', | |
d1b7e03d TH |
234 | "category IN ($categoryids) |
235 | AND parent = 0 | |
236 | AND hidden = 0 | |
237 | $extraconditions", '', 'id,id AS id2'); | |
238 | if (!$questionids) { | |
239 | $questionids = array(); | |
240 | } | |
241 | return $questionids; | |
242 | } | |
243 | } |