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