includes/resourceloader/ResourceLoaderWikiModule.php

   1 <?php
   2 /**
   3  * Abstraction for ResourceLoader modules that pull from wiki pages.
   4  *
   5  * This program 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 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program 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 along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @author Trevor Parscal
  22  * @author Roan Kattouw
  23  */
  24
  25 /**
  26  * Abstraction for ResourceLoader modules which pull from wiki pages
  27  *
  28  * This can only be used for wiki pages in the MediaWiki and User namespaces,
  29  * because of its dependence on the functionality of Title::isCssJsSubpage.
  30  *
  31  * This module supports being used as a placeholder for a module on a remote wiki.
  32  * To do so, getDB() must be overloaded to return a foreign database object that
  33  * allows local wikis to query page metadata.
  34  *
  35  * Safe for calls on local wikis are:
  36  * - Option getters:
  37  *   - getGroup()
  38  *   - getPosition()
  39  *   - getPages()
  40  * - Basic methods that strictly involve the foreign database
  41  *   - getDB()
  42  *   - isKnownEmpty()
  43  *   - getTitleInfo()
  44  */
  45 class ResourceLoaderWikiModule extends ResourceLoaderModule {
  46         /** @var string Position on the page to load this module at */
  47         protected $position = 'bottom';
  48
  49         // Origin defaults to users with sitewide authority
  50         protected $origin = self::ORIGIN_USER_SITEWIDE;
  51
  52         // In-process cache for title info
  53         protected $titleInfo = array();
  54
  55         // List of page names that contain CSS
  56         protected $styles = array();
  57
  58         // List of page names that contain JavaScript
  59         protected $scripts = array();
  60
  61         // Group of module
  62         protected $group;
  63
  64         /**
  65          * @param array $options For back-compat, this can be omitted in favour of overwriting getPages.
  66          */
  67         public function __construct( array $options = null ) {
  68                 if ( is_null( $options ) ) {
  69                         return;
  70                 }
  71
  72                 foreach ( $options as $member => $option ) {
  73                         switch ( $member ) {
  74                                 case 'position':
  75                                 case 'styles':
  76                                 case 'scripts':
  77                                 case 'group':
  78                                         $this->{$member} = $option;
  79                                         break;
  80                         }
  81                 }
  82         }
  83
  84         /**
  85          * Subclasses should return an associative array of resources in the module.
  86          * Keys should be the title of a page in the MediaWiki or User namespace.
  87          *
  88          * Values should be a nested array of options.  The supported keys are 'type' and
  89          * (CSS only) 'media'.
  90          *
  91          * For scripts, 'type' should be 'script'.
  92          *
  93          * For stylesheets, 'type' should be 'style'.
  94          * There is an optional media key, the value of which can be the
  95          * medium ('screen', 'print', etc.) of the stylesheet.
  96          *
  97          * @param ResourceLoaderContext $context
  98          * @return array
  99          */
 100         protected function getPages( ResourceLoaderContext $context ) {
 101                 $config = $this->getConfig();
 102                 $pages = array();
 103
 104                 // Filter out pages from origins not allowed by the current wiki configuration.
 105                 if ( $config->get( 'UseSiteJs' ) ) {
 106                         foreach ( $this->scripts as $script ) {
 107                                 $pages[$script] = array( 'type' => 'script' );
 108                         }
 109                 }
 110
 111                 if ( $config->get( 'UseSiteCss' ) ) {
 112                         foreach ( $this->styles as $style ) {
 113                                 $pages[$style] = array( 'type' => 'style' );
 114                         }
 115                 }
 116
 117                 return $pages;
 118         }
 119
 120         /**
 121          * Get group name
 122          *
 123          * @return string
 124          */
 125         public function getGroup() {
 126                 return $this->group;
 127         }
 128
 129         /**
 130          * Get the Database object used in getTitleInfo().
 131          *
 132          * Defaults to the local slave DB. Subclasses may want to override this to return a foreign
 133          * database object, or null if getTitleInfo() shouldn't access the database.
 134          *
 135          * NOTE: This ONLY works for getTitleInfo() and isKnownEmpty(), NOT FOR ANYTHING ELSE.
 136          * In particular, it doesn't work for getContent() or getScript() etc.
 137          *
 138          * @return IDatabase|null
 139          */
 140         protected function getDB() {
 141                 return wfGetDB( DB_SLAVE );
 142         }
 143
 144         /**
 145          * @param string $title
 146          * @return null|string
 147          */
 148         protected function getContent( $titleText ) {
 149                 $title = Title::newFromText( $titleText );
 150                 if ( !$title ) {
 151                         return null;
 152                 }
 153
 154                 $handler = ContentHandler::getForTitle( $title );
 155                 if ( $handler->isSupportedFormat( CONTENT_FORMAT_CSS ) ) {
 156                         $format = CONTENT_FORMAT_CSS;
 157                 } elseif ( $handler->isSupportedFormat( CONTENT_FORMAT_JAVASCRIPT ) ) {
 158                         $format = CONTENT_FORMAT_JAVASCRIPT;
 159                 } else {
 160                         return null;
 161                 }
 162
 163                 $revision = Revision::newFromTitle( $title, false, Revision::READ_NORMAL );
 164                 if ( !$revision ) {
 165                         return null;
 166                 }
 167
 168                 $content = $revision->getContent( Revision::RAW );
 169
 170                 if ( !$content ) {
 171                         wfDebugLog( 'resourceloader', __METHOD__ . ': failed to load content of JS/CSS page!' );
 172                         return null;
 173                 }
 174
 175                 return $content->serialize( $format );
 176         }
 177
 178         /**
 179          * @param ResourceLoaderContext $context
 180          * @return string
 181          */
 182         public function getScript( ResourceLoaderContext $context ) {
 183                 $scripts = '';
 184                 foreach ( $this->getPages( $context ) as $titleText => $options ) {
 185                         if ( $options['type'] !== 'script' ) {
 186                                 continue;
 187                         }
 188                         $script = $this->getContent( $titleText );
 189                         if ( strval( $script ) !== '' ) {
 190                                 $script = $this->validateScriptFile( $titleText, $script );
 191                                 $scripts .= ResourceLoader::makeComment( $titleText ) . $script . "\n";
 192                         }
 193                 }
 194                 return $scripts;
 195         }
 196
 197         /**
 198          * @param ResourceLoaderContext $context
 199          * @return array
 200          */
 201         public function getStyles( ResourceLoaderContext $context ) {
 202                 $styles = array();
 203                 foreach ( $this->getPages( $context ) as $titleText => $options ) {
 204                         if ( $options['type'] !== 'style' ) {
 205                                 continue;
 206                         }
 207                         $media = isset( $options['media'] ) ? $options['media'] : 'all';
 208                         $style = $this->getContent( $titleText );
 209                         if ( strval( $style ) === '' ) {
 210                                 continue;
 211                         }
 212                         if ( $this->getFlip( $context ) ) {
 213                                 $style = CSSJanus::transform( $style, true, false );
 214                         }
 215                         $style = MemoizedCallable::call( 'CSSMin::remap',
 216                                 array( $style, false, $this->getConfig()->get( 'ScriptPath' ), true ) );
 217                         if ( !isset( $styles[$media] ) ) {
 218                                 $styles[$media] = array();
 219                         }
 220                         $style = ResourceLoader::makeComment( $titleText ) . $style;
 221                         $styles[$media][] = $style;
 222                 }
 223                 return $styles;
 224         }
 225
 226         /**
 227          * Disable module content versioning.
 228          *
 229          * This class does not support generating content outside of a module
 230          * request due to foreign database support.
 231          *
 232          * See getDefinitionSummary() for meta-data versioning.
 233          *
 234          * @return bool
 235          */
 236         public function enableModuleContentVersion() {
 237                 return false;
 238         }
 239
 240         /**
 241          * @param ResourceLoaderContext $context
 242          * @return array
 243          */
 244         public function getDefinitionSummary( ResourceLoaderContext $context ) {
 245                 $summary = parent::getDefinitionSummary( $context );
 246                 $summary[] = array(
 247                         'pages' => $this->getPages( $context ),
 248                         // Includes SHA1 of content
 249                         'titleInfo' => $this->getTitleInfo( $context ),
 250                 );
 251                 return $summary;
 252         }
 253
 254         /**
 255          * @param ResourceLoaderContext $context
 256          * @return bool
 257          */
 258         public function isKnownEmpty( ResourceLoaderContext $context ) {
 259                 $revisions = $this->getTitleInfo( $context );
 260
 261                 // For user modules, don't needlessly load if there are no non-empty pages
 262                 if ( $this->getGroup() === 'user' ) {
 263                         foreach ( $revisions as $revision ) {
 264                                 if ( $revision['rev_len'] > 0 ) {
 265                                         // At least one non-empty page, module should be loaded
 266                                         return false;
 267                                 }
 268                         }
 269                         return true;
 270                 }
 271
 272                 // Bug 68488: For other modules (i.e. ones that are called in cached html output) only check
 273                 // page existance. This ensures that, if some pages in a module are temporarily blanked,
 274                 // we don't end omit the module's script or link tag on some pages.
 275                 return count( $revisions ) === 0;
 276         }
 277
 278         /**
 279          * Get the information about the wiki pages for a given context.
 280          * @param ResourceLoaderContext $context
 281          * @return array Keyed by page name. Contains arrays with 'rev_len' and 'rev_sha1' keys
 282          */
 283         protected function getTitleInfo( ResourceLoaderContext $context ) {
 284                 $dbr = $this->getDB();
 285                 if ( !$dbr ) {
 286                         // We're dealing with a subclass that doesn't have a DB
 287                         return array();
 288                 }
 289
 290                 $pages = $this->getPages( $context );
 291                 $key = implode( '|', array_keys( $pages ) );
 292                 if ( !isset( $this->titleInfo[$key] ) ) {
 293                         $this->titleInfo[$key] = array();
 294                         $batch = new LinkBatch;
 295                         foreach ( $pages as $titleText => $options ) {
 296                                 $batch->addObj( Title::newFromText( $titleText ) );
 297                         }
 298
 299                         if ( !$batch->isEmpty() ) {
 300                                 $res = $dbr->select( array( 'page', 'revision' ),
 301                                         array( 'page_namespace', 'page_title', 'rev_len', 'rev_sha1' ),
 302                                         $batch->constructSet( 'page', $dbr ),
 303                                         __METHOD__,
 304                                         array(),
 305                                         array( 'revision' => array( 'INNER JOIN', array( 'page_latest=rev_id' ) ) )
 306                                 );
 307                                 foreach ( $res as $row ) {
 308                                         // Avoid including ids or timestamps of revision/page tables so
 309                                         // that versions are not wasted
 310                                         $title = Title::makeTitle( $row->page_namespace, $row->page_title );
 311                                         $this->titleInfo[$key][$title->getPrefixedText()] = array(
 312                                                 'rev_len' => $row->rev_len,
 313                                                 'rev_sha1' => $row->rev_sha1,
 314                                         );
 315                                 }
 316                         }
 317                 }
 318                 return $this->titleInfo[$key];
 319         }
 320
 321         public function getPosition() {
 322                 return $this->position;
 323         }
 324 }