includes/Action.php

   1 <?php
   2 /**
   3  * Actions are things which can be done to pages (edit, delete, rollback, etc).  They
   4  * are distinct from Special Pages because an action must apply to exactly one page.
   5  *
   6  * To add an action in an extension, create a subclass of Action, and add the key to
   7  * $wgActions.  There is also the deprecated UnknownAction hook
   8  *
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
  23  *
  24  * @file
  25  */
  26 abstract class Action {
  27
  28         /**
  29          * Page on which we're performing the action
  30          * @var Page
  31          */
  32         protected $page;
  33
  34         /**
  35          * IContextSource if specified; otherwise we'll use the Context from the Page
  36          * @var IContextSource
  37          */
  38         protected $context;
  39
  40         /**
  41          * The fields used to create the HTMLForm
  42          * @var Array
  43          */
  44         protected $fields;
  45
  46         /**
  47          * Get the Action subclass which should be used to handle this action, false if
  48          * the action is disabled, or null if it's not recognised
  49          * @param $action String
  50          * @param $overrides Array
  51          * @return bool|null|string
  52          */
  53         private final static function getClass( $action, array $overrides ) {
  54                 global $wgActions;
  55                 $action = strtolower( $action );
  56
  57                 if ( !isset( $wgActions[$action] ) ) {
  58                         return null;
  59                 }
  60
  61                 if ( $wgActions[$action] === false ) {
  62                         return false;
  63                 } elseif ( $wgActions[$action] === true && isset( $overrides[$action] ) ) {
  64                         return $overrides[$action];
  65                 } elseif ( $wgActions[$action] === true ) {
  66                         return ucfirst( $action ) . 'Action';
  67                 } else {
  68                         return $wgActions[$action];
  69                 }
  70         }
  71
  72         /**
  73          * Get an appropriate Action subclass for the given action
  74          * @param $action String
  75          * @param $page Page
  76          * @param $context IContextSource
  77          * @return Action|false|null false if the action is disabled, null
  78          *     if it is not recognised
  79          */
  80         public final static function factory( $action, Page $page, IContextSource $context = null ) {
  81                 $class = self::getClass( $action, $page->getActionOverrides() );
  82                 if ( $class ) {
  83                         $obj = new $class( $page, $context );
  84                         return $obj;
  85                 }
  86                 return $class;
  87         }
  88
  89         /**
  90          * Get the action that will be executed, not necessarily the one passed
  91          * passed through the "action" request parameter. Actions disabled in
  92          * $wgActions will be replaced by "nosuchaction".
  93          *
  94          * @since 1.19
  95          * @param $context IContextSource
  96          * @return string: action name
  97          */
  98         public final static function getActionName( IContextSource $context ) {
  99                 global $wgActions;
 100
 101                 $request = $context->getRequest();
 102                 $actionName = $request->getVal( 'action', 'view' );
 103
 104                 // Check for disabled actions
 105                 if ( isset( $wgActions[$actionName] ) && $wgActions[$actionName] === false ) {
 106                         $actionName = 'nosuchaction';
 107                 }
 108
 109                 // Workaround for bug #20966: inability of IE to provide an action dependent
 110                 // on which submit button is clicked.
 111                 if ( $actionName === 'historysubmit' ) {
 112                         if ( $request->getBool( 'revisiondelete' ) ) {
 113                                 $actionName = 'revisiondelete';
 114                         } else {
 115                                 $actionName = 'view';
 116                         }
 117                 } elseif ( $actionName == 'editredlink' ) {
 118                         $actionName = 'edit';
 119                 }
 120
 121                 // Trying to get a WikiPage for NS_SPECIAL etc. will result
 122                 // in WikiPage::factory throwing "Invalid or virtual namespace -1 given."
 123                 // For SpecialPages et al, default to action=view.
 124                 if ( !$context->canUseWikiPage() ) {
 125                         return 'view';
 126                 }
 127
 128                 $action = Action::factory( $actionName, $context->getWikiPage() );
 129                 if ( $action instanceof Action ) {
 130                         return $action->getName();
 131                 }
 132
 133                 return 'nosuchaction';
 134         }
 135
 136         /**
 137          * Check if a given action is recognised, even if it's disabled
 138          *
 139          * @param $name String: name of an action
 140          * @return Bool
 141          */
 142         public final static function exists( $name ) {
 143                 return self::getClass( $name, array() ) !== null;
 144         }
 145
 146         /**
 147          * Get the IContextSource in use here
 148          * @return IContextSource
 149          */
 150         public final function getContext() {
 151                 if ( $this->context instanceof IContextSource ) {
 152                         return $this->context;
 153                 }
 154                 return $this->page->getContext();
 155         }
 156
 157         /**
 158          * Get the WebRequest being used for this instance
 159          *
 160          * @return WebRequest
 161          */
 162         public final function getRequest() {
 163                 return $this->getContext()->getRequest();
 164         }
 165
 166         /**
 167          * Get the OutputPage being used for this instance
 168          *
 169          * @return OutputPage
 170          */
 171         public final function getOutput() {
 172                 return $this->getContext()->getOutput();
 173         }
 174
 175         /**
 176          * Shortcut to get the User being used for this instance
 177          *
 178          * @return User
 179          */
 180         public final function getUser() {
 181                 return $this->getContext()->getUser();
 182         }
 183
 184         /**
 185          * Shortcut to get the Skin being used for this instance
 186          *
 187          * @return Skin
 188          */
 189         public final function getSkin() {
 190                 return $this->getContext()->getSkin();
 191         }
 192
 193         /**
 194          * Shortcut to get the user Language being used for this instance
 195          *
 196          * @return Language
 197          */
 198         public final function getLanguage() {
 199                 return $this->getContext()->getLanguage();
 200         }
 201
 202         /**
 203          * Shortcut to get the user Language being used for this instance
 204          *
 205          * @deprecated 1.19 Use getLanguage instead
 206          * @return Language
 207          */
 208         public final function getLang() {
 209                 wfDeprecated( __METHOD__, '1.19' );
 210                 return $this->getLanguage();
 211         }
 212
 213         /**
 214          * Shortcut to get the Title object from the page
 215          * @return Title
 216          */
 217         public final function getTitle() {
 218                 return $this->page->getTitle();
 219         }
 220
 221         /**
 222          * Get a Message object with context set
 223          * Parameters are the same as wfMessage()
 224          *
 225          * @return Message object
 226          */
 227         public final function msg() {
 228                 $params = func_get_args();
 229                 return call_user_func_array( array( $this->getContext(), 'msg' ), $params );
 230         }
 231
 232         /**
 233          * Protected constructor: use Action::factory( $action, $page ) to actually build
 234          * these things in the real world
 235          * @param $page Page
 236          * @param $context IContextSource
 237          */
 238         protected function __construct( Page $page, IContextSource $context = null ) {
 239                 $this->page = $page;
 240                 $this->context = $context;
 241         }
 242
 243         /**
 244          * Return the name of the action this object responds to
 245          * @return String lowercase
 246          */
 247         public abstract function getName();
 248
 249         /**
 250          * Get the permission required to perform this action.  Often, but not always,
 251          * the same as the action name
 252          * @return String|null
 253          */
 254         public function getRestriction() {
 255                 return null;
 256         }
 257
 258         /**
 259          * Checks if the given user (identified by an object) can perform this action.  Can be
 260          * overridden by sub-classes with more complicated permissions schemes.  Failures here
 261          * must throw subclasses of ErrorPageError
 262          *
 263          * @param $user User: the user to check, or null to use the context user
 264          * @throws ErrorPageError
 265          */
 266         protected function checkCanExecute( User $user ) {
 267                 $right = $this->getRestriction();
 268                 if ( $right !== null ) {
 269                         $errors = $this->getTitle()->getUserPermissionsErrors( $right, $user );
 270                         if ( count( $errors ) ) {
 271                                 throw new PermissionsError( $right, $errors );
 272                         }
 273                 }
 274
 275                 if ( $this->requiresUnblock() && $user->isBlocked() ) {
 276                         $block = $user->mBlock;
 277                         throw new UserBlockedError( $block );
 278                 }
 279
 280                 // This should be checked at the end so that the user won't think the
 281                 // error is only temporary when he also don't have the rights to execute
 282                 // this action
 283                 if ( $this->requiresWrite() && wfReadOnly() ) {
 284                         throw new ReadOnlyError();
 285                 }
 286         }
 287
 288         /**
 289          * Whether this action requires the wiki not to be locked
 290          * @return Bool
 291          */
 292         public function requiresWrite() {
 293                 return true;
 294         }
 295
 296         /**
 297          * Whether this action can still be executed by a blocked user
 298          * @return Bool
 299          */
 300         public function requiresUnblock() {
 301                 return true;
 302         }
 303
 304         /**
 305          * Set output headers for noindexing etc.  This function will not be called through
 306          * the execute() entry point, so only put UI-related stuff in here.
 307          */
 308         protected function setHeaders() {
 309                 $out = $this->getOutput();
 310                 $out->setRobotPolicy( "noindex,nofollow" );
 311                 $out->setPageTitle( $this->getPageTitle() );
 312                 $this->getOutput()->setSubtitle( $this->getDescription() );
 313                 $out->setArticleRelated( true );
 314         }
 315
 316         /**
 317          * Returns the name that goes in the \<h1\> page title
 318          *
 319          * @return String
 320          */
 321         protected function getPageTitle() {
 322                 return $this->getTitle()->getPrefixedText();
 323         }
 324
 325         /**
 326          * Returns the description that goes below the \<h1\> tag
 327          *
 328          * @return String
 329          */
 330         protected function getDescription() {
 331                 return wfMsgHtml( strtolower( $this->getName() ) );
 332         }
 333
 334         /**
 335          * The main action entry point.  Do all output for display and send it to the context
 336          * output.  Do not use globals $wgOut, $wgRequest, etc, in implementations; use
 337          * $this->getOutput(), etc.
 338          * @throws ErrorPageError
 339          */
 340         public abstract function show();
 341
 342         /**
 343          * Execute the action in a silent fashion: do not display anything or release any errors.
 344          * @return Bool whether execution was successful
 345          */
 346         public abstract function execute();
 347 }
 348
 349 abstract class FormAction extends Action {
 350
 351         /**
 352          * Get an HTMLForm descriptor array
 353          * @return Array
 354          */
 355         protected abstract function getFormFields();
 356
 357         /**
 358          * Add pre- or post-text to the form
 359          * @return String HTML which will be sent to $form->addPreText()
 360          */
 361         protected function preText() { return ''; }
 362
 363         /**
 364          * @return string
 365          */
 366         protected function postText() { return ''; }
 367
 368         /**
 369          * Play with the HTMLForm if you need to more substantially
 370          * @param $form HTMLForm
 371          */
 372         protected function alterForm( HTMLForm $form ) {}
 373
 374         /**
 375          * Get the HTMLForm to control behaviour
 376          * @return HTMLForm|null
 377          */
 378         protected function getForm() {
 379                 $this->fields = $this->getFormFields();
 380
 381                 // Give hooks a chance to alter the form, adding extra fields or text etc
 382                 wfRunHooks( 'ActionModifyFormFields', array( $this->getName(), &$this->fields, $this->page ) );
 383
 384                 $form = new HTMLForm( $this->fields, $this->getContext() );
 385                 $form->setSubmitCallback( array( $this, 'onSubmit' ) );
 386
 387                 // Retain query parameters (uselang etc)
 388                 $form->addHiddenField( 'action', $this->getName() ); // Might not be the same as the query string
 389                 $params = array_diff_key(
 390                         $this->getRequest()->getQueryValues(),
 391                         array( 'action' => null, 'title' => null )
 392                 );
 393                 $form->addHiddenField( 'redirectparams', wfArrayToCGI( $params ) );
 394
 395                 $form->addPreText( $this->preText() );
 396                 $form->addPostText( $this->postText() );
 397                 $this->alterForm( $form );
 398
 399                 // Give hooks a chance to alter the form, adding extra fields or text etc
 400                 wfRunHooks( 'ActionBeforeFormDisplay', array( $this->getName(), &$form, $this->page ) );
 401
 402                 return $form;
 403         }
 404
 405         /**
 406          * Process the form on POST submission.  If you return false from getFormFields(),
 407          * this will obviously never be reached.  If you don't want to do anything with the
 408          * form, just return false here
 409          * @param  $data Array
 410          * @return Bool|Array true for success, false for didn't-try, array of errors on failure
 411          */
 412         public abstract function onSubmit( $data );
 413
 414         /**
 415          * Do something exciting on successful processing of the form.  This might be to show
 416          * a confirmation message (watch, rollback, etc) or to redirect somewhere else (edit,
 417          * protect, etc).
 418          */
 419         public abstract function onSuccess();
 420
 421         /**
 422          * The basic pattern for actions is to display some sort of HTMLForm UI, maybe with
 423          * some stuff underneath (history etc); to do some processing on submission of that
 424          * form (delete, protect, etc) and to do something exciting on 'success', be that
 425          * display something new or redirect to somewhere.  Some actions have more exotic
 426          * behaviour, but that's what subclassing is for :D
 427          */
 428         public function show() {
 429                 $this->setHeaders();
 430
 431                 // This will throw exceptions if there's a problem
 432                 $this->checkCanExecute( $this->getUser() );
 433
 434                 $form = $this->getForm();
 435                 if ( $form->show() ) {
 436                         $this->onSuccess();
 437                 }
 438         }
 439
 440         /**
 441          * @see Action::execute()
 442          * @throws ErrorPageError
 443          * @param array|null $data
 444          * @param bool $captureErrors
 445          * @return bool
 446          */
 447         public function execute( array $data = null, $captureErrors = true ) {
 448                 try {
 449                         // Set a new context so output doesn't leak.
 450                         $this->context = clone $this->page->getContext();
 451
 452                         // This will throw exceptions if there's a problem
 453                         $this->checkCanExecute( $this->getUser() );
 454
 455                         $fields = array();
 456                         foreach ( $this->fields as $key => $params ) {
 457                                 if ( isset( $data[$key] ) ) {
 458                                         $fields[$key] = $data[$key];
 459                                 } elseif ( isset( $params['default'] ) ) {
 460                                         $fields[$key] = $params['default'];
 461                                 } else {
 462                                         $fields[$key] = null;
 463                                 }
 464                         }
 465                         $status = $this->onSubmit( $fields );
 466                         if ( $status === true ) {
 467                                 // This might do permanent stuff
 468                                 $this->onSuccess();
 469                                 return true;
 470                         } else {
 471                                 return false;
 472                         }
 473                 }
 474                 catch ( ErrorPageError $e ) {
 475                         if ( $captureErrors ) {
 476                                 return false;
 477                         } else {
 478                                 throw $e;
 479                         }
 480                 }
 481         }
 482 }
 483
 484 /**
 485  * Actions generally fall into two groups: the show-a-form-then-do-something-with-the-input
 486  * format (protect, delete, move, etc), and the just-do-something format (watch, rollback,
 487  * patrol, etc).
 488  */
 489 abstract class FormlessAction extends Action {
 490
 491         /**
 492          * Show something on GET request.
 493          * @return String|null will be added to the HTMLForm if present, or just added to the
 494          *     output if not.  Return null to not add anything
 495          */
 496         public abstract function onView();
 497
 498         /**
 499          * We don't want an HTMLForm
 500          */
 501         protected function getFormFields() {
 502                 return false;
 503         }
 504
 505         public function onSubmit( $data ) {
 506                 return false;
 507         }
 508
 509         public function onSuccess() {
 510                 return false;
 511         }
 512
 513         public function show() {
 514                 $this->setHeaders();
 515
 516                 // This will throw exceptions if there's a problem
 517                 $this->checkCanExecute( $this->getUser() );
 518
 519                 $this->getOutput()->addHTML( $this->onView() );
 520         }
 521
 522         /**
 523          * Execute the action silently, not giving any output.  Since these actions don't have
 524          * forms, they probably won't have any data, but some (eg rollback) may do
 525          * @param $data Array values that would normally be in the GET request
 526          * @param $captureErrors Bool whether to catch exceptions and just return false
 527          * @return Bool whether execution was successful
 528          */
 529         public function execute( array $data = null, $captureErrors = true ) {
 530                 try {
 531                         // Set a new context so output doesn't leak.
 532                         $this->context = clone $this->page->getContext();
 533                         if ( is_array( $data ) ) {
 534                                 $this->context->setRequest( new FauxRequest( $data, false ) );
 535                         }
 536
 537                         // This will throw exceptions if there's a problem
 538                         $this->checkCanExecute( $this->getUser() );
 539
 540                         $this->onView();
 541                         return true;
 542                 }
 543                 catch ( ErrorPageError $e ) {
 544                         if ( $captureErrors ) {
 545                                 return false;
 546                         } else {
 547                                 throw $e;
 548                         }
 549                 }
 550         }
 551 }