[ResourceLoader 2]: Add support for multiple loadScript sources
[lhc/web/wiklou.git] / includes / resourceloader / ResourceLoaderModule.php
1 <?php
2 /**
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation; either version 2 of the License, or
6 * (at your option) any later version.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
16 * http://www.gnu.org/copyleft/gpl.html
17 *
18 * @file
19 * @author Trevor Parscal
20 * @author Roan Kattouw
21 */
22
23 /**
24 * Abstraction for resource loader modules, with name registration and maxage functionality.
25 */
26 abstract class ResourceLoaderModule {
27
28 # Type of resource
29 const TYPE_SCRIPTS = 'scripts';
30 const TYPE_STYLES = 'styles';
31 const TYPE_MESSAGES = 'messages';
32 const TYPE_COMBINED = 'combined';
33
34 # sitewide core module like a skin file or jQuery component
35 const ORIGIN_CORE_SITEWIDE = 1;
36
37 # per-user module generated by the software
38 const ORIGIN_CORE_INDIVIDUAL = 2;
39
40 # sitewide module generated from user-editable files, like MediaWiki:Common.js, or
41 # modules accessible to multiple users, such as those generated by the Gadgets extension.
42 const ORIGIN_USER_SITEWIDE = 3;
43
44 # per-user module generated from user-editable files, like User:Me/vector.js
45 const ORIGIN_USER_INDIVIDUAL = 4;
46
47 # an access constant; make sure this is kept as the largest number in this group
48 const ORIGIN_ALL = 10;
49
50 # script and style modules form a hierarchy of trustworthiness, with core modules like
51 # skins and jQuery as most trustworthy, and user scripts as least trustworthy. We can
52 # limit the types of scripts and styles we allow to load on, say, sensitive special
53 # pages like Special:UserLogin and Special:Preferences
54 protected $origin = self::ORIGIN_CORE_SITEWIDE;
55
56 /* Protected Members */
57
58 protected $name = null;
59
60 // In-object cache for file dependencies
61 protected $fileDeps = array();
62 // In-object cache for message blob mtime
63 protected $msgBlobMtime = array();
64
65 /* Methods */
66
67 /**
68 * Get this module's name. This is set when the module is registered
69 * with ResourceLoader::register()
70 *
71 * @return Mixed: Name (string) or null if no name was set
72 */
73 public function getName() {
74 return $this->name;
75 }
76
77 /**
78 * Set this module's name. This is called by ResourceLodaer::register()
79 * when registering the module. Other code should not call this.
80 *
81 * @param $name String: Name
82 */
83 public function setName( $name ) {
84 $this->name = $name;
85 }
86
87 /**
88 * Get this module's origin. This is set when the module is registered
89 * with ResourceLoader::register()
90 *
91 * @return Int ResourceLoaderModule class constant, the subclass default
92 * if not set manuall
93 */
94 public function getOrigin() {
95 return $this->origin;
96 }
97
98 /**
99 * Set this module's origin. This is called by ResourceLodaer::register()
100 * when registering the module. Other code should not call this.
101 *
102 * @param $origin Int origin
103 */
104 public function setOrigin( $origin ) {
105 $this->origin = $origin;
106 }
107
108 /**
109 * @param $context ResourceLoaderContext
110 * @return bool
111 */
112 public function getFlip( $context ) {
113 global $wgContLang;
114
115 return $wgContLang->getDir() !== $context->getDirection();
116 }
117
118 /**
119 * Get all JS for this module for a given language and skin.
120 * Includes all relevant JS except loader scripts.
121 *
122 * @param $context ResourceLoaderContext: Context object
123 * @return String: JavaScript code
124 */
125 public function getScript( ResourceLoaderContext $context ) {
126 // Stub, override expected
127 return '';
128 }
129
130 /**
131 * Get all CSS for this module for a given skin.
132 *
133 * @param $context ResourceLoaderContext: Context object
134 * @return Array: List of CSS strings keyed by media type
135 */
136 public function getStyles( ResourceLoaderContext $context ) {
137 // Stub, override expected
138 return array();
139 }
140
141 /**
142 * Get the messages needed for this module.
143 *
144 * To get a JSON blob with messages, use MessageBlobStore::get()
145 *
146 * @return Array: List of message keys. Keys may occur more than once
147 */
148 public function getMessages() {
149 // Stub, override expected
150 return array();
151 }
152
153 /**
154 * Get the group this module is in.
155 *
156 * @return String: Group name
157 */
158 public function getGroup() {
159 // Stub, override expected
160 return null;
161 }
162
163 /**
164 * Get the origin of this module. Should only be overridden for foreign modules.
165 *
166 * @return String: Origin name, 'local' for local modules
167 */
168 public function getSource() {
169 // Stub, override expected
170 return 'local';
171 }
172
173 /**
174 * Where on the HTML page should this module's JS be loaded?
175 * 'top': in the <head>
176 * 'bottom': at the bottom of the <body>
177 *
178 * @return string
179 */
180 public function getPosition() {
181 return 'bottom';
182 }
183
184 /**
185 * Get the loader JS for this module, if set.
186 *
187 * @return Mixed: JavaScript loader code as a string or boolean false if no custom loader set
188 */
189 public function getLoaderScript() {
190 // Stub, override expected
191 return false;
192 }
193
194 /**
195 * Get a list of modules this module depends on.
196 *
197 * Dependency information is taken into account when loading a module
198 * on the client side. When adding a module on the server side,
199 * dependency information is NOT taken into account and YOU are
200 * responsible for adding dependent modules as well. If you don't do
201 * this, the client side loader will send a second request back to the
202 * server to fetch the missing modules, which kind of defeats the
203 * purpose of the resource loader.
204 *
205 * To add dependencies dynamically on the client side, use a custom
206 * loader script, see getLoaderScript()
207 * @return Array: List of module names as strings
208 */
209 public function getDependencies() {
210 // Stub, override expected
211 return array();
212 }
213
214 /**
215 * Get the files this module depends on indirectly for a given skin.
216 * Currently these are only image files referenced by the module's CSS.
217 *
218 * @param $skin String: Skin name
219 * @return Array: List of files
220 */
221 public function getFileDependencies( $skin ) {
222 // Try in-object cache first
223 if ( isset( $this->fileDeps[$skin] ) ) {
224 return $this->fileDeps[$skin];
225 }
226
227 $dbr = wfGetDB( DB_SLAVE );
228 $deps = $dbr->selectField( 'module_deps', 'md_deps', array(
229 'md_module' => $this->getName(),
230 'md_skin' => $skin,
231 ), __METHOD__
232 );
233 if ( !is_null( $deps ) ) {
234 $this->fileDeps[$skin] = (array) FormatJson::decode( $deps, true );
235 } else {
236 $this->fileDeps[$skin] = array();
237 }
238 return $this->fileDeps[$skin];
239 }
240
241 /**
242 * Set preloaded file dependency information. Used so we can load this
243 * information for all modules at once.
244 * @param $skin String: Skin name
245 * @param $deps Array: Array of file names
246 */
247 public function setFileDependencies( $skin, $deps ) {
248 $this->fileDeps[$skin] = $deps;
249 }
250
251 /**
252 * Get the last modification timestamp of the message blob for this
253 * module in a given language.
254 * @param $lang String: Language code
255 * @return Integer: UNIX timestamp, or 0 if the module doesn't have messages
256 */
257 public function getMsgBlobMtime( $lang ) {
258 if ( !isset( $this->msgBlobMtime[$lang] ) ) {
259 if ( !count( $this->getMessages() ) )
260 return 0;
261
262 $dbr = wfGetDB( DB_SLAVE );
263 $msgBlobMtime = $dbr->selectField( 'msg_resource', 'mr_timestamp', array(
264 'mr_resource' => $this->getName(),
265 'mr_lang' => $lang
266 ), __METHOD__
267 );
268 // If no blob was found, but the module does have messages, that means we need
269 // to regenerate it. Return NOW
270 if ( $msgBlobMtime === false ) {
271 $msgBlobMtime = wfTimestampNow();
272 }
273 $this->msgBlobMtime[$lang] = wfTimestamp( TS_UNIX, $msgBlobMtime );
274 }
275 return $this->msgBlobMtime[$lang];
276 }
277
278 /**
279 * Set a preloaded message blob last modification timestamp. Used so we
280 * can load this information for all modules at once.
281 * @param $lang String: Language code
282 * @param $mtime Integer: UNIX timestamp or 0 if there is no such blob
283 */
284 public function setMsgBlobMtime( $lang, $mtime ) {
285 $this->msgBlobMtime[$lang] = $mtime;
286 }
287
288 /* Abstract Methods */
289
290 /**
291 * Get this module's last modification timestamp for a given
292 * combination of language, skin and debug mode flag. This is typically
293 * the highest of each of the relevant components' modification
294 * timestamps. Whenever anything happens that changes the module's
295 * contents for these parameters, the mtime should increase.
296 *
297 * @param $context ResourceLoaderContext: Context object
298 * @return Integer: UNIX timestamp
299 */
300 public function getModifiedTime( ResourceLoaderContext $context ) {
301 // 0 would mean now
302 return 1;
303 }
304
305 /**
306 * Check whether this module is known to be empty. If a child class
307 * has an easy and cheap way to determine that this module is
308 * definitely going to be empty, it should override this method to
309 * return true in that case. Callers may optimize the request for this
310 * module away if this function returns true.
311 * @param $context ResourceLoaderContext: Context object
312 * @return Boolean
313 */
314 public function isKnownEmpty( ResourceLoaderContext $context ) {
315 return false;
316 }
317
318
319 /** @var JSParser lazy-initialized; use self::javaScriptParser() */
320 private static $jsParser;
321 private static $parseCacheVersion = 1;
322
323 /**
324 * Validate a given script file; if valid returns the original source.
325 * If invalid, returns replacement JS source that throws an exception.
326 *
327 * @param string $fileName
328 * @param string $contents
329 * @return string JS with the original, or a replacement error
330 */
331 protected function validateScriptFile( $fileName, $contents ) {
332 global $wgResourceLoaderValidateJS;
333 if ( $wgResourceLoaderValidateJS ) {
334 // Try for cache hit
335 // Use CACHE_ANYTHING since filtering is very slow compared to DB queries
336 $key = wfMemcKey( 'resourceloader', 'jsparse', self::$parseCacheVersion, md5( $contents ) );
337 $cache = wfGetCache( CACHE_ANYTHING );
338 $cacheEntry = $cache->get( $key );
339 if ( is_string( $cacheEntry ) ) {
340 return $cacheEntry;
341 }
342
343 $parser = self::javaScriptParser();
344 try {
345 $parser->parse( $contents, $fileName, 1 );
346 $result = $contents;
347 } catch (Exception $e) {
348 // We'll save this to cache to avoid having to validate broken JS over and over...
349 $err = $e->getMessage();
350 $result = "throw new Error(" . Xml::encodeJsVar("JavaScript parse error: $err") . ");";
351 }
352
353 $cache->set( $key, $result );
354 return $result;
355 } else {
356 return $contents;
357 }
358 }
359
360 protected static function javaScriptParser() {
361 if ( !self::$jsParser ) {
362 self::$jsParser = new JSParser();
363 }
364 return self::$jsParser;
365 }
366
367 }