includes/resourceloader/ResourceLoaderWikiModule.php

   1 <?php
   2 /**
   3  * Abstraction for resource loader modules which 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 resource loader 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                                         $this->isPositionDefined = true;
  76                                         // Don't break since we need the member set as well
  77                                 case 'styles':
  78                                 case 'scripts':
  79                                 case 'group':
  80                                         $this->{$member} = $option;
  81                                         break;
  82                         }
  83                 }
  84         }
  85
  86         /**
  87          * Subclasses should return an associative array of resources in the module.
  88          * Keys should be the title of a page in the MediaWiki or User namespace.
  89          *
  90          * Values should be a nested array of options.  The supported keys are 'type' and
  91          * (CSS only) 'media'.
  92          *
  93          * For scripts, 'type' should be 'script'.
  94          *
  95          * For stylesheets, 'type' should be 'style'.
  96          * There is an optional media key, the value of which can be the
  97          * medium ('screen', 'print', etc.) of the stylesheet.
  98          *
  99          * @param ResourceLoaderContext $context
 100          * @return array
 101          */
 102         protected function getPages( ResourceLoaderContext $context ) {
 103                 $config = $this->getConfig();
 104                 $pages = array();
 105
 106                 // Filter out pages from origins not allowed by the current wiki configuration.
 107                 if ( $config->get( 'UseSiteJs' ) ) {
 108                         foreach ( $this->scripts as $script ) {
 109                                 $pages[$script] = array( 'type' => 'script' );
 110                         }
 111                 }
 112
 113                 if ( $config->get( 'UseSiteCss' ) ) {
 114                         foreach ( $this->styles as $style ) {
 115                                 $pages[$style] = array( 'type' => 'style' );
 116                         }
 117                 }
 118
 119                 return $pages;
 120         }
 121
 122         /**
 123          * Get group name
 124          *
 125          * @return string
 126          */
 127         public function getGroup() {
 128                 return $this->group;
 129         }
 130
 131         /**
 132          * Get the Database object used in getTitleInfo().
 133          *
 134          * Defaults to the local slave DB. Subclasses may want to override this to return a foreign
 135          * database object, or null if getTitleInfo() shouldn't access the database.
 136          *
 137          * NOTE: This ONLY works for getTitleInfo() and isKnownEmpty(), NOT FOR ANYTHING ELSE.
 138          * In particular, it doesn't work for getContent() or getScript() etc.
 139          *
 140          * @return IDatabase|null
 141          */
 142         protected function getDB() {
 143                 return wfGetDB( DB_SLAVE );
 144         }
 145
 146         /**
 147          * @param string $title
 148          * @return null|string
 149          */
 150         protected function getContent( $titleText ) {
 151                 $title = Title::newFromText( $titleText );
 152                 if ( !$title ) {
 153                         return null;
 154                 }
 155
 156                 $handler = ContentHandler::getForTitle( $title );
 157                 if ( $handler->isSupportedFormat( CONTENT_FORMAT_CSS ) ) {
 158                         $format = CONTENT_FORMAT_CSS;
 159                 } elseif ( $handler->isSupportedFormat( CONTENT_FORMAT_JAVASCRIPT ) ) {
 160                         $format = CONTENT_FORMAT_JAVASCRIPT;
 161                 } else {
 162                         return null;
 163                 }
 164
 165                 $revision = Revision::newFromTitle( $title, false, Revision::READ_NORMAL );
 166                 if ( !$revision ) {
 167                         return null;
 168                 }
 169
 170                 $content = $revision->getContent( Revision::RAW );
 171
 172                 if ( !$content ) {
 173                         wfDebugLog( 'resourceloader', __METHOD__ . ': failed to load content of JS/CSS page!' );
 174                         return null;
 175                 }
 176
 177                 return $content->serialize( $format );
 178         }
 179
 180         /**
 181          * @param ResourceLoaderContext $context
 182          * @return string
 183          */
 184         public function getScript( ResourceLoaderContext $context ) {
 185                 $scripts = '';
 186                 foreach ( $this->getPages( $context ) as $titleText => $options ) {
 187                         if ( $options['type'] !== 'script' ) {
 188                                 continue;
 189                         }
 190                         $script = $this->getContent( $titleText );
 191                         if ( strval( $script ) !== '' ) {
 192                                 $script = $this->validateScriptFile( $titleText, $script );
 193                                 $scripts .= ResourceLoader::makeComment( $titleText ) . $script . "\n";
 194                         }
 195                 }
 196                 return $scripts;
 197         }
 198
 199         /**
 200          * @param ResourceLoaderContext $context
 201          * @return array
 202          */
 203         public function getStyles( ResourceLoaderContext $context ) {
 204                 $styles = array();
 205                 foreach ( $this->getPages( $context ) as $titleText => $options ) {
 206                         if ( $options['type'] !== 'style' ) {
 207                                 continue;
 208                         }
 209                         $media = isset( $options['media'] ) ? $options['media'] : 'all';
 210                         $style = $this->getContent( $titleText );
 211                         if ( strval( $style ) === '' ) {
 212                                 continue;
 213                         }
 214                         if ( $this->getFlip( $context ) ) {
 215                                 $style = CSSJanus::transform( $style, true, false );
 216                         }
 217                         $style = CSSMin::remap( $style, false, $this->getConfig()->get( 'ScriptPath' ), true );
 218                         if ( !isset( $styles[$media] ) ) {
 219                                 $styles[$media] = array();
 220                         }
 221                         $style = ResourceLoader::makeComment( $titleText ) . $style;
 222                         $styles[$media][] = $style;
 223                 }
 224                 return $styles;
 225         }
 226
 227         /**
 228          * Disable module content versioning.
 229          *
 230          * This class does not support generating content outside of a module
 231          * request due to foreign database support.
 232          *
 233          * See getDefinitionSummary() for meta-data versioning.
 234          *
 235          * @return bool
 236          */
 237         public function enableModuleContentVersion() {
 238                 return false;
 239         }
 240
 241         /**
 242          * @param ResourceLoaderContext $context
 243          * @return array
 244          */
 245         public function getDefinitionSummary( ResourceLoaderContext $context ) {
 246                 $summary = parent::getDefinitionSummary( $context );
 247                 $summary[] = array(
 248                         'pages' => $this->getPages( $context ),
 249                         // Includes SHA1 of content
 250                         'titleInfo' => $this->getTitleInfo( $context ),
 251                 );
 252                 return $summary;
 253         }
 254
 255         /**
 256          * @param ResourceLoaderContext $context
 257          * @return bool
 258          */
 259         public function isKnownEmpty( ResourceLoaderContext $context ) {
 260                 $revisions = $this->getTitleInfo( $context );
 261
 262                 // For user modules, don't needlessly load if there are no non-empty pages
 263                 if ( $this->getGroup() === 'user' ) {
 264                         foreach ( $revisions as $revision ) {
 265                                 if ( $revision['rev_len'] > 0 ) {
 266                                         // At least one non-empty page, module should be loaded
 267                                         return false;
 268                                 }
 269                         }
 270                         return true;
 271                 }
 272
 273                 // Bug 68488: For other modules (i.e. ones that are called in cached html output) only check
 274                 // page existance. This ensures that, if some pages in a module are temporarily blanked,
 275                 // we don't end omit the module's script or link tag on some pages.
 276                 return count( $revisions ) === 0;
 277         }
 278
 279         /**
 280          * Get the information about the wiki pages for a given context.
 281          * @param ResourceLoaderContext $context
 282          * @return array Keyed by page name. Contains arrays with 'rev_len' and 'rev_sha1' keys
 283          */
 284         protected function getTitleInfo( ResourceLoaderContext $context ) {
 285                 $dbr = $this->getDB();
 286                 if ( !$dbr ) {
 287                         // We're dealing with a subclass that doesn't have a DB
 288                         return array();
 289                 }
 290
 291                 $pages = $this->getPages( $context );
 292                 $key = implode( '|', array_keys( $pages ) );
 293                 if ( !isset( $this->titleInfo[$key] ) ) {
 294                         $this->titleInfo[$key] = array();
 295                         $batch = new LinkBatch;
 296                         foreach ( $pages as $titleText => $options ) {
 297                                 $batch->addObj( Title::newFromText( $titleText ) );
 298                         }
 299
 300                         if ( !$batch->isEmpty() ) {
 301                                 $res = $dbr->select( array( 'page', 'revision' ),
 302                                         array( 'page_namespace', 'page_title', 'rev_len', 'rev_sha1' ),
 303                                         $batch->constructSet( 'page', $dbr ),
 304                                         __METHOD__,
 305                                         array(),
 306                                         array( 'revision' => array( 'INNER JOIN', array( 'page_latest=rev_id' ) ) )
 307                                 );
 308                                 foreach ( $res as $row ) {
 309                                         // Avoid including ids or timestamps of revision/page tables so
 310                                         // that versions are not wasted
 311                                         $title = Title::makeTitle( $row->page_namespace, $row->page_title );
 312                                         $this->titleInfo[$key][$title->getPrefixedText()] = array(
 313                                                 'rev_len' => $row->rev_len,
 314                                                 'rev_sha1' => $row->rev_sha1,
 315                                         );
 316                                 }
 317                         }
 318                 }
 319                 return $this->titleInfo[$key];
 320         }
 321
 322         public function getPosition() {
 323                 return $this->position;
 324         }
 325 }