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 $name Int origin
 103          */
 104         public function setOrigin( $origin ) {
 105                 $this->origin = $origin;
 106         }
 107
 108         /**
 109          * Get whether CSS for this module should be flipped
 110          * @param $context ResourceLoaderContext
 111          * @return bool
 112          */
 113         public function getFlip( $context ) {
 114                 return $context->getDirection() === 'rtl';
 115         }
 116
 117         /**
 118          * Get all JS for this module for a given language and skin.
 119          * Includes all relevant JS except loader scripts.
 120          *
 121          * @param $context ResourceLoaderContext: Context object
 122          * @return String: JavaScript code
 123          */
 124         public function getScript( ResourceLoaderContext $context ) {
 125                 // Stub, override expected
 126                 return '';
 127         }
 128
 129         /**
 130          * Get all CSS for this module for a given skin.
 131          *
 132          * @param $context ResourceLoaderContext: Context object
 133          * @return Array: List of CSS strings keyed by media type
 134          */
 135         public function getStyles( ResourceLoaderContext $context ) {
 136                 // Stub, override expected
 137                 return '';
 138         }
 139
 140         /**
 141          * Get the messages needed for this module.
 142          *
 143          * To get a JSON blob with messages, use MessageBlobStore::get()
 144          *
 145          * @return Array: List of message keys. Keys may occur more than once
 146          */
 147         public function getMessages() {
 148                 // Stub, override expected
 149                 return array();
 150         }
 151
 152         /**
 153          * Get the group this module is in.
 154          *
 155          * @return String: Group name
 156          */
 157         public function getGroup() {
 158                 // Stub, override expected
 159                 return null;
 160         }
 161
 162         /**
 163          * Get the loader JS for this module, if set.
 164          *
 165          * @return Mixed: JavaScript loader code as a string or boolean false if no custom loader set
 166          */
 167         public function getLoaderScript() {
 168                 // Stub, override expected
 169                 return false;
 170         }
 171
 172         /**
 173          * Get a list of modules this module depends on.
 174          *
 175          * Dependency information is taken into account when loading a module
 176          * on the client side. When adding a module on the server side,
 177          * dependency information is NOT taken into account and YOU are
 178          * responsible for adding dependent modules as well. If you don't do
 179          * this, the client side loader will send a second request back to the
 180          * server to fetch the missing modules, which kind of defeats the
 181          * purpose of the resource loader.
 182          *
 183          * To add dependencies dynamically on the client side, use a custom
 184          * loader script, see getLoaderScript()
 185          * @return Array: List of module names as strings
 186          */
 187         public function getDependencies() {
 188                 // Stub, override expected
 189                 return array();
 190         }
 191
 192         /**
 193          * Get the files this module depends on indirectly for a given skin.
 194          * Currently these are only image files referenced by the module's CSS.
 195          *
 196          * @param $skin String: Skin name
 197          * @return Array: List of files
 198          */
 199         public function getFileDependencies( $skin ) {
 200                 // Try in-object cache first
 201                 if ( isset( $this->fileDeps[$skin] ) ) {
 202                         return $this->fileDeps[$skin];
 203                 }
 204
 205                 $dbr = wfGetDB( DB_SLAVE );
 206                 $deps = $dbr->selectField( 'module_deps', 'md_deps', array(
 207                                 'md_module' => $this->getName(),
 208                                 'md_skin' => $skin,
 209                         ), __METHOD__
 210                 );
 211                 if ( !is_null( $deps ) ) {
 212                         $this->fileDeps[$skin] = (array) FormatJson::decode( $deps, true );
 213                 } else {
 214                         $this->fileDeps[$skin] = array();
 215                 }
 216                 return $this->fileDeps[$skin];
 217         }
 218
 219         /**
 220          * Set preloaded file dependency information. Used so we can load this
 221          * information for all modules at once.
 222          * @param $skin String: Skin name
 223          * @param $deps Array: Array of file names
 224          */
 225         public function setFileDependencies( $skin, $deps ) {
 226                 $this->fileDeps[$skin] = $deps;
 227         }
 228
 229         /**
 230          * Get the last modification timestamp of the message blob for this
 231          * module in a given language.
 232          * @param $lang String: Language code
 233          * @return Integer: UNIX timestamp, or 0 if the module doesn't have messages
 234          */
 235         public function getMsgBlobMtime( $lang ) {
 236                 if ( !isset( $this->msgBlobMtime[$lang] ) ) {
 237                         if ( !count( $this->getMessages() ) )
 238                                 return 0;
 239
 240                         $dbr = wfGetDB( DB_SLAVE );
 241                         $msgBlobMtime = $dbr->selectField( 'msg_resource', 'mr_timestamp', array(
 242                                         'mr_resource' => $this->getName(),
 243                                         'mr_lang' => $lang
 244                                 ), __METHOD__
 245                         );
 246                         // If no blob was found, but the module does have messages, that means we need
 247                         // to regenerate it. Return NOW
 248                         if ( $msgBlobMtime === false ) {
 249                                 $msgBlobMtime = wfTimestampNow();
 250                         }
 251                         $this->msgBlobMtime[$lang] = wfTimestamp( TS_UNIX, $msgBlobMtime );
 252                 }
 253                 return $this->msgBlobMtime[$lang];
 254         }
 255
 256         /**
 257          * Set a preloaded message blob last modification timestamp. Used so we
 258          * can load this information for all modules at once.
 259          * @param $lang String: Language code
 260          * @param $mtime Integer: UNIX timestamp or 0 if there is no such blob
 261          */
 262         public function setMsgBlobMtime( $lang, $mtime ) {
 263                 $this->msgBlobMtime[$lang] = $mtime;
 264         }
 265
 266         /* Abstract Methods */
 267
 268         /**
 269          * Get this module's last modification timestamp for a given
 270          * combination of language, skin and debug mode flag. This is typically
 271          * the highest of each of the relevant components' modification
 272          * timestamps. Whenever anything happens that changes the module's
 273          * contents for these parameters, the mtime should increase.
 274          *
 275          * @param $context ResourceLoaderContext: Context object
 276          * @return Integer: UNIX timestamp
 277          */
 278         public function getModifiedTime( ResourceLoaderContext $context ) {
 279                 // 0 would mean now
 280                 return 1;
 281         }
 282
 283         /**
 284          * Check whether this module is known to be empty. If a child class
 285          * has an easy and cheap way to determine that this module is
 286          * definitely going to be empty, it should override this method to
 287          * return true in that case. Callers may optimize the request for this
 288          * module away if this function returns true.
 289          * @param $context ResourceLoaderContext: Context object
 290          * @return Boolean
 291          */
 292         public function isKnownEmpty( ResourceLoaderContext $context ) {
 293                 return false;
 294         }
 295 }