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          * Where on the HTML page should this module's JS be loaded?
 165          * 'top': in the <head>
 166          * 'bottom': at the bottom of the <body>
 167          *
 168          * @return string
 169          */
 170         public function getPosition() {
 171                 return 'bottom';
 172         }
 173
 174         /**
 175          * Get the loader JS for this module, if set.
 176          *
 177          * @return Mixed: JavaScript loader code as a string or boolean false if no custom loader set
 178          */
 179         public function getLoaderScript() {
 180                 // Stub, override expected
 181                 return false;
 182         }
 183
 184         /**
 185          * Get a list of modules this module depends on.
 186          *
 187          * Dependency information is taken into account when loading a module
 188          * on the client side. When adding a module on the server side,
 189          * dependency information is NOT taken into account and YOU are
 190          * responsible for adding dependent modules as well. If you don't do
 191          * this, the client side loader will send a second request back to the
 192          * server to fetch the missing modules, which kind of defeats the
 193          * purpose of the resource loader.
 194          *
 195          * To add dependencies dynamically on the client side, use a custom
 196          * loader script, see getLoaderScript()
 197          * @return Array: List of module names as strings
 198          */
 199         public function getDependencies() {
 200                 // Stub, override expected
 201                 return array();
 202         }
 203
 204         /**
 205          * Get the files this module depends on indirectly for a given skin.
 206          * Currently these are only image files referenced by the module's CSS.
 207          *
 208          * @param $skin String: Skin name
 209          * @return Array: List of files
 210          */
 211         public function getFileDependencies( $skin ) {
 212                 // Try in-object cache first
 213                 if ( isset( $this->fileDeps[$skin] ) ) {
 214                         return $this->fileDeps[$skin];
 215                 }
 216
 217                 $dbr = wfGetDB( DB_SLAVE );
 218                 $deps = $dbr->selectField( 'module_deps', 'md_deps', array(
 219                                 'md_module' => $this->getName(),
 220                                 'md_skin' => $skin,
 221                         ), __METHOD__
 222                 );
 223                 if ( !is_null( $deps ) ) {
 224                         $this->fileDeps[$skin] = (array) FormatJson::decode( $deps, true );
 225                 } else {
 226                         $this->fileDeps[$skin] = array();
 227                 }
 228                 return $this->fileDeps[$skin];
 229         }
 230
 231         /**
 232          * Set preloaded file dependency information. Used so we can load this
 233          * information for all modules at once.
 234          * @param $skin String: Skin name
 235          * @param $deps Array: Array of file names
 236          */
 237         public function setFileDependencies( $skin, $deps ) {
 238                 $this->fileDeps[$skin] = $deps;
 239         }
 240
 241         /**
 242          * Get the last modification timestamp of the message blob for this
 243          * module in a given language.
 244          * @param $lang String: Language code
 245          * @return Integer: UNIX timestamp, or 0 if the module doesn't have messages
 246          */
 247         public function getMsgBlobMtime( $lang ) {
 248                 if ( !isset( $this->msgBlobMtime[$lang] ) ) {
 249                         if ( !count( $this->getMessages() ) )
 250                                 return 0;
 251
 252                         $dbr = wfGetDB( DB_SLAVE );
 253                         $msgBlobMtime = $dbr->selectField( 'msg_resource', 'mr_timestamp', array(
 254                                         'mr_resource' => $this->getName(),
 255                                         'mr_lang' => $lang
 256                                 ), __METHOD__
 257                         );
 258                         // If no blob was found, but the module does have messages, that means we need
 259                         // to regenerate it. Return NOW
 260                         if ( $msgBlobMtime === false ) {
 261                                 $msgBlobMtime = wfTimestampNow();
 262                         }
 263                         $this->msgBlobMtime[$lang] = wfTimestamp( TS_UNIX, $msgBlobMtime );
 264                 }
 265                 return $this->msgBlobMtime[$lang];
 266         }
 267
 268         /**
 269          * Set a preloaded message blob last modification timestamp. Used so we
 270          * can load this information for all modules at once.
 271          * @param $lang String: Language code
 272          * @param $mtime Integer: UNIX timestamp or 0 if there is no such blob
 273          */
 274         public function setMsgBlobMtime( $lang, $mtime ) {
 275                 $this->msgBlobMtime[$lang] = $mtime;
 276         }
 277
 278         /* Abstract Methods */
 279
 280         /**
 281          * Get this module's last modification timestamp for a given
 282          * combination of language, skin and debug mode flag. This is typically
 283          * the highest of each of the relevant components' modification
 284          * timestamps. Whenever anything happens that changes the module's
 285          * contents for these parameters, the mtime should increase.
 286          *
 287          * @param $context ResourceLoaderContext: Context object
 288          * @return Integer: UNIX timestamp
 289          */
 290         public function getModifiedTime( ResourceLoaderContext $context ) {
 291                 // 0 would mean now
 292                 return 1;
 293         }
 294
 295         /**
 296          * Check whether this module is known to be empty. If a child class
 297          * has an easy and cheap way to determine that this module is
 298          * definitely going to be empty, it should override this method to
 299          * return true in that case. Callers may optimize the request for this
 300          * module away if this function returns true.
 301          * @param $context ResourceLoaderContext: Context object
 302          * @return Boolean
 303          */
 304         public function isKnownEmpty( ResourceLoaderContext $context ) {
 305                 return false;
 306         }
 307 }