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