includes/context/RequestContext.php

   1 <?php
   2 /**
   3  * Request-dependant objects containers.
   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  * @since 1.18
  21  *
  22  * @author Alexandre Emsenhuber
  23  * @author Daniel Friesen
  24  * @file
  25  */
  26
  27 /**
  28  * Group all the pieces relevant to the context of a request into one instance
  29  */
  30 class RequestContext implements IContextSource {
  31         /**
  32          * @var WebRequest
  33          */
  34         private $request;
  35
  36         /**
  37          * @var Title
  38          */
  39         private $title;
  40
  41         /**
  42          * @var WikiPage
  43          */
  44         private $wikipage;
  45
  46         /**
  47          * @var OutputPage
  48          */
  49         private $output;
  50
  51         /**
  52          * @var User
  53          */
  54         private $user;
  55
  56         /**
  57          * @var Language
  58          */
  59         private $lang;
  60
  61         /**
  62          * @var Skin
  63          */
  64         private $skin;
  65
  66         /**
  67          * @var Config
  68          */
  69         private $config;
  70
  71         /**
  72          * @var RequestContext
  73          */
  74         private static $instance = null;
  75
  76         /**
  77          * Set the Config object
  78          *
  79          * @param Config $c
  80          */
  81         public function setConfig( Config $c ) {
  82                 $this->config = $c;
  83         }
  84
  85         /**
  86          * Get the Config object
  87          *
  88          * @return Config
  89          */
  90         public function getConfig() {
  91                 if ( $this->config === null ) {
  92                         // @todo In the future, we could move this to WebStart.php so
  93                         // the Config object is ready for when initialization happens
  94                         $this->config = ConfigFactory::getDefaultInstance()->makeConfig( 'main' );
  95                 }
  96
  97                 return $this->config;
  98         }
  99
 100         /**
 101          * Set the WebRequest object
 102          *
 103          * @param WebRequest $r
 104          */
 105         public function setRequest( WebRequest $r ) {
 106                 $this->request = $r;
 107         }
 108
 109         /**
 110          * Get the WebRequest object
 111          *
 112          * @return WebRequest
 113          */
 114         public function getRequest() {
 115                 if ( $this->request === null ) {
 116                         global $wgRequest; # fallback to $wg till we can improve this
 117                         $this->request = $wgRequest;
 118                 }
 119
 120                 return $this->request;
 121         }
 122
 123         /**
 124          * Set the Title object
 125          *
 126          * @param Title $t
 127          * @throws MWException
 128          */
 129         public function setTitle( $t ) {
 130                 if ( $t !== null && !$t instanceof Title ) {
 131                         throw new MWException( __METHOD__ . " expects an instance of Title" );
 132                 }
 133                 $this->title = $t;
 134                 // Erase the WikiPage so a new one with the new title gets created.
 135                 $this->wikipage = null;
 136         }
 137
 138         /**
 139          * Get the Title object
 140          *
 141          * @return Title|null
 142          */
 143         public function getTitle() {
 144                 if ( $this->title === null ) {
 145                         global $wgTitle; # fallback to $wg till we can improve this
 146                         $this->title = $wgTitle;
 147                 }
 148
 149                 return $this->title;
 150         }
 151
 152         /**
 153          * Check whether a WikiPage object can be get with getWikiPage().
 154          * Callers should expect that an exception is thrown from getWikiPage()
 155          * if this method returns false.
 156          *
 157          * @since 1.19
 158          * @return bool
 159          */
 160         public function canUseWikiPage() {
 161                 if ( $this->wikipage !== null ) {
 162                         # If there's a WikiPage object set, we can for sure get it
 163                         return true;
 164                 }
 165                 $title = $this->getTitle();
 166                 if ( $title === null ) {
 167                         # No Title, no WikiPage
 168                         return false;
 169                 } else {
 170                         # Only namespaces whose pages are stored in the database can have WikiPage
 171                         return $title->canExist();
 172                 }
 173         }
 174
 175         /**
 176          * Set the WikiPage object
 177          *
 178          * @since 1.19
 179          * @param WikiPage $p
 180          */
 181         public function setWikiPage( WikiPage $p ) {
 182                 $contextTitle = $this->getTitle();
 183                 $pageTitle = $p->getTitle();
 184                 if ( !$contextTitle || !$pageTitle->equals( $contextTitle ) ) {
 185                         $this->setTitle( $pageTitle );
 186                 }
 187                 // Defer this to the end since setTitle sets it to null.
 188                 $this->wikipage = $p;
 189         }
 190
 191         /**
 192          * Get the WikiPage object.
 193          * May throw an exception if there's no Title object set or the Title object
 194          * belongs to a special namespace that doesn't have WikiPage, so use first
 195          * canUseWikiPage() to check whether this method can be called safely.
 196          *
 197          * @since 1.19
 198          * @throws MWException
 199          * @return WikiPage
 200          */
 201         public function getWikiPage() {
 202                 if ( $this->wikipage === null ) {
 203                         $title = $this->getTitle();
 204                         if ( $title === null ) {
 205                                 throw new MWException( __METHOD__ . ' called without Title object set' );
 206                         }
 207                         $this->wikipage = WikiPage::factory( $title );
 208                 }
 209
 210                 return $this->wikipage;
 211         }
 212
 213         /**
 214          * @param OutputPage $o
 215          */
 216         public function setOutput( OutputPage $o ) {
 217                 $this->output = $o;
 218         }
 219
 220         /**
 221          * Get the OutputPage object
 222          *
 223          * @return OutputPage
 224          */
 225         public function getOutput() {
 226                 if ( $this->output === null ) {
 227                         $this->output = new OutputPage( $this );
 228                 }
 229
 230                 return $this->output;
 231         }
 232
 233         /**
 234          * Set the User object
 235          *
 236          * @param User $u
 237          */
 238         public function setUser( User $u ) {
 239                 $this->user = $u;
 240         }
 241
 242         /**
 243          * Get the User object
 244          *
 245          * @return User
 246          */
 247         public function getUser() {
 248                 if ( $this->user === null ) {
 249                         $this->user = User::newFromSession( $this->getRequest() );
 250                 }
 251
 252                 return $this->user;
 253         }
 254
 255         /**
 256          * Accepts a language code and ensures it's sane. Outputs a cleaned up language
 257          * code and replaces with $wgLanguageCode if not sane.
 258          * @param string $code Language code
 259          * @return string
 260          */
 261         public static function sanitizeLangCode( $code ) {
 262                 global $wgLanguageCode;
 263
 264                 // BCP 47 - letter case MUST NOT carry meaning
 265                 $code = strtolower( $code );
 266
 267                 # Validate $code
 268                 if ( empty( $code ) || !Language::isValidCode( $code ) || ( $code === 'qqq' ) ) {
 269                         wfDebug( "Invalid user language code\n" );
 270                         $code = $wgLanguageCode;
 271                 }
 272
 273                 return $code;
 274         }
 275
 276         /**
 277          * Set the Language object
 278          *
 279          * @param Language|string $l Language instance or language code
 280          * @throws MWException
 281          * @since 1.19
 282          */
 283         public function setLanguage( $l ) {
 284                 if ( $l instanceof Language ) {
 285                         $this->lang = $l;
 286                 } elseif ( is_string( $l ) ) {
 287                         $l = self::sanitizeLangCode( $l );
 288                         $obj = Language::factory( $l );
 289                         $this->lang = $obj;
 290                 } else {
 291                         throw new MWException( __METHOD__ . " was passed an invalid type of data." );
 292                 }
 293         }
 294
 295         /**
 296          * Get the Language object.
 297          * Initialization of user or request objects can depend on this.
 298          *
 299          * @return Language
 300          * @since 1.19
 301          */
 302         public function getLanguage() {
 303                 if ( isset( $this->recursion ) ) {
 304                         trigger_error( "Recursion detected in " . __METHOD__, E_USER_WARNING );
 305                         $e = new Exception;
 306                         wfDebugLog( 'recursion-guard', "Recursion detected:\n" . $e->getTraceAsString() );
 307
 308                         global $wgLanguageCode;
 309                         $code = ( $wgLanguageCode ) ? $wgLanguageCode : 'en';
 310                         $this->lang = Language::factory( $code );
 311                 } elseif ( $this->lang === null ) {
 312                         $this->recursion = true;
 313
 314                         global $wgLanguageCode, $wgContLang;
 315
 316                         try {
 317                                 $request = $this->getRequest();
 318                                 $user = $this->getUser();
 319
 320                                 $code = $request->getVal( 'uselang', $user->getOption( 'language' ) );
 321                                 $code = self::sanitizeLangCode( $code );
 322
 323                                 wfRunHooks( 'UserGetLanguageObject', array( $user, &$code, $this ) );
 324
 325                                 if ( $code === $wgLanguageCode ) {
 326                                         $this->lang = $wgContLang;
 327                                 } else {
 328                                         $obj = Language::factory( $code );
 329                                         $this->lang = $obj;
 330                                 }
 331
 332                                 unset( $this->recursion );
 333                         }
 334                         catch ( Exception $ex ) {
 335                                 unset( $this->recursion );
 336                                 throw $ex;
 337                         }
 338                 }
 339
 340                 return $this->lang;
 341         }
 342
 343         /**
 344          * Set the Skin object
 345          *
 346          * @param Skin $s
 347          */
 348         public function setSkin( Skin $s ) {
 349                 $this->skin = clone $s;
 350                 $this->skin->setContext( $this );
 351         }
 352
 353         /**
 354          * Get the Skin object
 355          *
 356          * @return Skin
 357          */
 358         public function getSkin() {
 359                 if ( $this->skin === null ) {
 360                         wfProfileIn( __METHOD__ . '-createskin' );
 361
 362                         $skin = null;
 363                         wfRunHooks( 'RequestContextCreateSkin', array( $this, &$skin ) );
 364
 365                         // If the hook worked try to set a skin from it
 366                         if ( $skin instanceof Skin ) {
 367                                 $this->skin = $skin;
 368                         } elseif ( is_string( $skin ) ) {
 369                                 $this->skin = Skin::newFromKey( $skin );
 370                         }
 371
 372                         // If this is still null (the hook didn't run or didn't work)
 373                         // then go through the normal processing to load a skin
 374                         if ( $this->skin === null ) {
 375                                 global $wgHiddenPrefs;
 376                                 if ( !in_array( 'skin', $wgHiddenPrefs ) ) {
 377                                         # get the user skin
 378                                         $userSkin = $this->getUser()->getOption( 'skin' );
 379                                         $userSkin = $this->getRequest()->getVal( 'useskin', $userSkin );
 380                                 } else {
 381                                         # if we're not allowing users to override, then use the default
 382                                         global $wgDefaultSkin;
 383                                         $userSkin = $wgDefaultSkin;
 384                                 }
 385
 386                                 $this->skin = Skin::newFromKey( $userSkin );
 387                         }
 388
 389                         // After all that set a context on whatever skin got created
 390                         $this->skin->setContext( $this );
 391                         wfProfileOut( __METHOD__ . '-createskin' );
 392                 }
 393
 394                 return $this->skin;
 395         }
 396
 397         /** Helpful methods **/
 398
 399         /**
 400          * Get a Message object with context set
 401          * Parameters are the same as wfMessage()
 402          *
 403          * @return Message
 404          */
 405         public function msg() {
 406                 $args = func_get_args();
 407
 408                 return call_user_func_array( 'wfMessage', $args )->setContext( $this );
 409         }
 410
 411         /** Static methods **/
 412
 413         /**
 414          * Get the RequestContext object associated with the main request
 415          *
 416          * @return RequestContext
 417          */
 418         public static function getMain() {
 419                 if ( self::$instance === null ) {
 420                         self::$instance = new self;
 421                 }
 422
 423                 return self::$instance;
 424         }
 425
 426         /**
 427          * Resets singleton returned by getMain(). Should be called only from unit tests.
 428          */
 429         public static function resetMain() {
 430                 if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
 431                         throw new MWException( __METHOD__ . '() should be called only from unit tests!' );
 432                 }
 433                 self::$instance = null;
 434         }
 435
 436         /**
 437          * Export the resolved user IP, HTTP headers, user ID, and session ID.
 438          * The result will be reasonably sized to allow for serialization.
 439          *
 440          * @return array
 441          * @since 1.21
 442          */
 443         public function exportSession() {
 444                 return array(
 445                         'ip' => $this->getRequest()->getIP(),
 446                         'headers' => $this->getRequest()->getAllHeaders(),
 447                         'sessionId' => session_id(),
 448                         'userId' => $this->getUser()->getId()
 449                 );
 450         }
 451
 452         /**
 453          * Import the resolved user IP, HTTP headers, user ID, and session ID.
 454          * This sets the current session and sets $wgUser and $wgRequest.
 455          * Once the return value falls out of scope, the old context is restored.
 456          * This function can only be called within CLI mode scripts.
 457          *
 458          * This will setup the session from the given ID. This is useful when
 459          * background scripts inherit context when acting on behalf of a user.
 460          *
 461          * @note suhosin.session.encrypt may interfere with this method.
 462          *
 463          * @param array $params Result of RequestContext::exportSession()
 464          * @return ScopedCallback
 465          * @throws MWException
 466          * @since 1.21
 467          */
 468         public static function importScopedSession( array $params ) {
 469                 if ( PHP_SAPI !== 'cli' ) {
 470                         // Don't send random private cookies or turn $wgRequest into FauxRequest
 471                         throw new MWException( "Sessions can only be imported in cli mode." );
 472                 } elseif ( !strlen( $params['sessionId'] ) ) {
 473                         throw new MWException( "No session ID was specified." );
 474                 }
 475
 476                 if ( $params['userId'] ) { // logged-in user
 477                         $user = User::newFromId( $params['userId'] );
 478                         if ( !$user ) {
 479                                 throw new MWException( "No user with ID '{$params['userId']}'." );
 480                         }
 481                 } elseif ( !IP::isValid( $params['ip'] ) ) {
 482                         throw new MWException( "Could not load user '{$params['ip']}'." );
 483                 } else { // anon user
 484                         $user = User::newFromName( $params['ip'], false );
 485                 }
 486
 487                 $importSessionFunction = function ( User $user, array $params ) {
 488                         global $wgRequest, $wgUser;
 489
 490                         $context = RequestContext::getMain();
 491                         // Commit and close any current session
 492                         session_write_close(); // persist
 493                         session_id( '' ); // detach
 494                         $_SESSION = array(); // clear in-memory array
 495                         // Remove any user IP or agent information
 496                         $context->setRequest( new FauxRequest() );
 497                         $wgRequest = $context->getRequest(); // b/c
 498                         // Now that all private information is detached from the user, it should
 499                         // be safe to load the new user. If errors occur or an exception is thrown
 500                         // and caught (leaving the main context in a mixed state), there is no risk
 501                         // of the User object being attached to the wrong IP, headers, or session.
 502                         $context->setUser( $user );
 503                         $wgUser = $context->getUser(); // b/c
 504                         if ( strlen( $params['sessionId'] ) ) { // don't make a new random ID
 505                                 wfSetupSession( $params['sessionId'] ); // sets $_SESSION
 506                         }
 507                         $request = new FauxRequest( array(), false, $_SESSION );
 508                         $request->setIP( $params['ip'] );
 509                         foreach ( $params['headers'] as $name => $value ) {
 510                                 $request->setHeader( $name, $value );
 511                         }
 512                         // Set the current context to use the new WebRequest
 513                         $context->setRequest( $request );
 514                         $wgRequest = $context->getRequest(); // b/c
 515                 };
 516
 517                 // Stash the old session and load in the new one
 518                 $oUser = self::getMain()->getUser();
 519                 $oParams = self::getMain()->exportSession();
 520                 $importSessionFunction( $user, $params );
 521
 522                 // Set callback to save and close the new session and reload the old one
 523                 return new ScopedCallback( function () use ( $importSessionFunction, $oUser, $oParams ) {
 524                         $importSessionFunction( $oUser, $oParams );
 525                 } );
 526         }
 527
 528         /**
 529          * Create a new extraneous context. The context is filled with information
 530          * external to the current session.
 531          * - Title is specified by argument
 532          * - Request is a FauxRequest, or a FauxRequest can be specified by argument
 533          * - User is an anonymous user, for separation IPv4 localhost is used
 534          * - Language will be based on the anonymous user and request, may be content
 535          *   language or a uselang param in the fauxrequest data may change the lang
 536          * - Skin will be based on the anonymous user, should be the wiki's default skin
 537          *
 538          * @param Title $title Title to use for the extraneous request
 539          * @param WebRequest|array $request A WebRequest or data to use for a FauxRequest
 540          * @return RequestContext
 541          */
 542         public static function newExtraneousContext( Title $title, $request = array() ) {
 543                 $context = new self;
 544                 $context->setTitle( $title );
 545                 if ( $request instanceof WebRequest ) {
 546                         $context->setRequest( $request );
 547                 } else {
 548                         $context->setRequest( new FauxRequest( $request ) );
 549                 }
 550                 $context->user = User::newFromName( '127.0.0.1', false );
 551
 552                 return $context;
 553         }
 554 }