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 = [];
  54
  55         // List of page names that contain CSS
  56         protected $styles = [];
  57
  58         // List of page names that contain JavaScript
  59         protected $scripts = [];
  60
  61         // Group of module
  62         protected $group;
  63
  64         // Whether to enable variable expansion (e.g. "{skin}")
  65         protected $allowVariables = false;
  66
  67         /**
  68          * @param array $options For back-compat, this can be omitted in favour of overwriting getPages.
  69          */
  70         public function __construct( array $options = null ) {
  71                 if ( is_null( $options ) ) {
  72                         return;
  73                 }
  74
  75                 foreach ( $options as $member => $option ) {
  76                         switch ( $member ) {
  77                                 case 'position':
  78                                 case 'styles':
  79                                 case 'scripts':
  80                                 case 'group':
  81                                 case 'targets':
  82                                 case 'allowVariables':
  83                                         $this->{$member} = $option;
  84                                         break;
  85                         }
  86                 }
  87         }
  88
  89         /**
  90          * Subclasses should return an associative array of resources in the module.
  91          * Keys should be the title of a page in the MediaWiki or User namespace.
  92          *
  93          * Values should be a nested array of options.  The supported keys are 'type' and
  94          * (CSS only) 'media'.
  95          *
  96          * For scripts, 'type' should be 'script'.
  97          *
  98          * For stylesheets, 'type' should be 'style'.
  99          * There is an optional media key, the value of which can be the
 100          * medium ('screen', 'print', etc.) of the stylesheet.
 101          *
 102          * @param ResourceLoaderContext $context
 103          * @return array
 104          */
 105         protected function getPages( ResourceLoaderContext $context ) {
 106                 $config = $this->getConfig();
 107                 $pages = [];
 108
 109                 // Filter out pages from origins not allowed by the current wiki configuration.
 110                 if ( $config->get( 'UseSiteJs' ) ) {
 111                         foreach ( $this->scripts as $script ) {
 112                                 $page = $this->expandVariables( $context, $script );
 113                                 $pages[$page] = [ 'type' => 'script' ];
 114                         }
 115                 }
 116
 117                 if ( $config->get( 'UseSiteCss' ) ) {
 118                         foreach ( $this->styles as $style ) {
 119                                 $page = $this->expandVariables( $context, $style );
 120                                 $pages[$page] = [ 'type' => 'style' ];
 121                         }
 122                 }
 123
 124                 return $pages;
 125         }
 126
 127         private function expandVariables( ResourceLoaderContext $context, $pageName ) {
 128                 if ( !$this->allowVariables ) {
 129                         return $pageName;
 130                 }
 131                 return strtr( $pageName, [
 132                         '{skin}' => $context->getSkin()
 133                 ] );
 134         }
 135
 136         /**
 137          * Get group name
 138          *
 139          * @return string
 140          */
 141         public function getGroup() {
 142                 return $this->group;
 143         }
 144
 145         /**
 146          * Get the Database object used in getTitleInfo().
 147          *
 148          * Defaults to the local slave DB. Subclasses may want to override this to return a foreign
 149          * database object, or null if getTitleInfo() shouldn't access the database.
 150          *
 151          * NOTE: This ONLY works for getTitleInfo() and isKnownEmpty(), NOT FOR ANYTHING ELSE.
 152          * In particular, it doesn't work for getContent() or getScript() etc.
 153          *
 154          * @return IDatabase|null
 155          */
 156         protected function getDB() {
 157                 return wfGetDB( DB_SLAVE );
 158         }
 159
 160         /**
 161          * @param string $title
 162          * @return null|string
 163          */
 164         protected function getContent( $titleText ) {
 165                 $title = Title::newFromText( $titleText );
 166                 if ( !$title ) {
 167                         return null;
 168                 }
 169
 170                 $handler = ContentHandler::getForTitle( $title );
 171                 if ( $handler->isSupportedFormat( CONTENT_FORMAT_CSS ) ) {
 172                         $format = CONTENT_FORMAT_CSS;
 173                 } elseif ( $handler->isSupportedFormat( CONTENT_FORMAT_JAVASCRIPT ) ) {
 174                         $format = CONTENT_FORMAT_JAVASCRIPT;
 175                 } else {
 176                         return null;
 177                 }
 178
 179                 $revision = Revision::newFromTitle( $title, false, Revision::READ_NORMAL );
 180                 if ( !$revision ) {
 181                         return null;
 182                 }
 183
 184                 $content = $revision->getContent( Revision::RAW );
 185
 186                 if ( !$content ) {
 187                         wfDebugLog( 'resourceloader', __METHOD__ . ': failed to load content of JS/CSS page!' );
 188                         return null;
 189                 }
 190
 191                 return $content->serialize( $format );
 192         }
 193
 194         /**
 195          * @param ResourceLoaderContext $context
 196          * @return string
 197          */
 198         public function getScript( ResourceLoaderContext $context ) {
 199                 $scripts = '';
 200                 foreach ( $this->getPages( $context ) as $titleText => $options ) {
 201                         if ( $options['type'] !== 'script' ) {
 202                                 continue;
 203                         }
 204                         $script = $this->getContent( $titleText );
 205                         if ( strval( $script ) !== '' ) {
 206                                 $script = $this->validateScriptFile( $titleText, $script );
 207                                 $scripts .= ResourceLoader::makeComment( $titleText ) . $script . "\n";
 208                         }
 209                 }
 210                 return $scripts;
 211         }
 212
 213         /**
 214          * @param ResourceLoaderContext $context
 215          * @return array
 216          */
 217         public function getStyles( ResourceLoaderContext $context ) {
 218                 $styles = [];
 219                 foreach ( $this->getPages( $context ) as $titleText => $options ) {
 220                         if ( $options['type'] !== 'style' ) {
 221                                 continue;
 222                         }
 223                         $media = isset( $options['media'] ) ? $options['media'] : 'all';
 224                         $style = $this->getContent( $titleText );
 225                         if ( strval( $style ) === '' ) {
 226                                 continue;
 227                         }
 228                         if ( $this->getFlip( $context ) ) {
 229                                 $style = CSSJanus::transform( $style, true, false );
 230                         }
 231                         $style = MemoizedCallable::call( 'CSSMin::remap',
 232                                 [ $style, false, $this->getConfig()->get( 'ScriptPath' ), true ] );
 233                         if ( !isset( $styles[$media] ) ) {
 234                                 $styles[$media] = [];
 235                         }
 236                         $style = ResourceLoader::makeComment( $titleText ) . $style;
 237                         $styles[$media][] = $style;
 238                 }
 239                 return $styles;
 240         }
 241
 242         /**
 243          * Disable module content versioning.
 244          *
 245          * This class does not support generating content outside of a module
 246          * request due to foreign database support.
 247          *
 248          * See getDefinitionSummary() for meta-data versioning.
 249          *
 250          * @return bool
 251          */
 252         public function enableModuleContentVersion() {
 253                 return false;
 254         }
 255
 256         /**
 257          * @param ResourceLoaderContext $context
 258          * @return array
 259          */
 260         public function getDefinitionSummary( ResourceLoaderContext $context ) {
 261                 $summary = parent::getDefinitionSummary( $context );
 262                 $summary[] = [
 263                         'pages' => $this->getPages( $context ),
 264                         // Includes SHA1 of content
 265                         'titleInfo' => $this->getTitleInfo( $context ),
 266                 ];
 267                 return $summary;
 268         }
 269
 270         /**
 271          * @param ResourceLoaderContext $context
 272          * @return bool
 273          */
 274         public function isKnownEmpty( ResourceLoaderContext $context ) {
 275                 $revisions = $this->getTitleInfo( $context );
 276
 277                 // For user modules, don't needlessly load if there are no non-empty pages
 278                 if ( $this->getGroup() === 'user' ) {
 279                         foreach ( $revisions as $revision ) {
 280                                 if ( $revision['rev_len'] > 0 ) {
 281                                         // At least one non-empty page, module should be loaded
 282                                         return false;
 283                                 }
 284                         }
 285                         return true;
 286                 }
 287
 288                 // Bug 68488: For other modules (i.e. ones that are called in cached html output) only check
 289                 // page existance. This ensures that, if some pages in a module are temporarily blanked,
 290                 // we don't end omit the module's script or link tag on some pages.
 291                 return count( $revisions ) === 0;
 292         }
 293
 294         /**
 295          * Get the information about the wiki pages for a given context.
 296          * @param ResourceLoaderContext $context
 297          * @return array Keyed by page name. Contains arrays with 'rev_len' and 'rev_sha1' keys
 298          */
 299         protected function getTitleInfo( ResourceLoaderContext $context ) {
 300                 $dbr = $this->getDB();
 301                 if ( !$dbr ) {
 302                         // We're dealing with a subclass that doesn't have a DB
 303                         return [];
 304                 }
 305
 306                 $pages = $this->getPages( $context );
 307                 $key = implode( '|', array_keys( $pages ) );
 308                 if ( !isset( $this->titleInfo[$key] ) ) {
 309                         $this->titleInfo[$key] = [];
 310                         $batch = new LinkBatch;
 311                         foreach ( $pages as $titleText => $options ) {
 312                                 $batch->addObj( Title::newFromText( $titleText ) );
 313                         }
 314
 315                         if ( !$batch->isEmpty() ) {
 316                                 $res = $dbr->select( [ 'page', 'revision' ],
 317                                         // Include page_touched to allow purging if cache is poisoned (T117587, T113916)
 318                                         [ 'page_namespace', 'page_title', 'page_touched', 'rev_len', 'rev_sha1' ],
 319                                         $batch->constructSet( 'page', $dbr ),
 320                                         __METHOD__,
 321                                         [],
 322                                         [ 'revision' => [ 'INNER JOIN', [ 'page_latest=rev_id' ] ] ]
 323                                 );
 324                                 foreach ( $res as $row ) {
 325                                         // Avoid including ids or timestamps of revision/page tables so
 326                                         // that versions are not wasted
 327                                         $title = Title::makeTitle( $row->page_namespace, $row->page_title );
 328                                         $this->titleInfo[$key][$title->getPrefixedText()] = [
 329                                                 'rev_len' => $row->rev_len,
 330                                                 'rev_sha1' => $row->rev_sha1,
 331                                                 'page_touched' => $row->page_touched,
 332                                         ];
 333                                 }
 334                         }
 335                 }
 336                 return $this->titleInfo[$key];
 337         }
 338
 339         public function getPosition() {
 340                 return $this->position;
 341         }
 342 }