includes/Action.php

   1 <?php
   2 /**
   3  * @defgroup Actions Action done on pages
   4  */
   5
   6 /**
   7  * Actions are things which can be done to pages (edit, delete, rollback, etc).  They
   8  * are distinct from Special Pages because an action must apply to exactly one page.
   9  *
  10  * To add an action in an extension, create a subclass of Action, and add the key to
  11  * $wgActions.  There is also the deprecated UnknownAction hook
  12  *
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * This program is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with this program; if not, write to the Free Software
  26  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
  27  *
  28  * @file
  29  */
  30 abstract class Action {
  31
  32         /**
  33          * Page on which we're performing the action
  34          * @var Page
  35          */
  36         protected $page;
  37
  38         /**
  39          * IContextSource if specified; otherwise we'll use the Context from the Page
  40          * @var IContextSource
  41          */
  42         protected $context;
  43
  44         /**
  45          * The fields used to create the HTMLForm
  46          * @var Array
  47          */
  48         protected $fields;
  49
  50         /**
  51          * Get the Action subclass which should be used to handle this action, false if
  52          * the action is disabled, or null if it's not recognised
  53          * @param $action String
  54          * @param $overrides Array
  55          * @return bool|null|string
  56          */
  57         private final static function getClass( $action, array $overrides ) {
  58                 global $wgActions;
  59                 $action = strtolower( $action );
  60
  61                 if ( !isset( $wgActions[$action] ) ) {
  62                         return null;
  63                 }
  64
  65                 if ( $wgActions[$action] === false ) {
  66                         return false;
  67                 } elseif ( $wgActions[$action] === true && isset( $overrides[$action] ) ) {
  68                         return $overrides[$action];
  69                 } elseif ( $wgActions[$action] === true ) {
  70                         return ucfirst( $action ) . 'Action';
  71                 } else {
  72                         return $wgActions[$action];
  73                 }
  74         }
  75
  76         /**
  77          * Get an appropriate Action subclass for the given action
  78          * @param $action String
  79          * @param $page Page
  80          * @param $context IContextSource
  81          * @return Action|false|null false if the action is disabled, null
  82          *     if it is not recognised
  83          */
  84         public final static function factory( $action, Page $page, IContextSource $context = null ) {
  85                 $class = self::getClass( $action, $page->getActionOverrides() );
  86                 if ( $class ) {
  87                         $obj = new $class( $page, $context );
  88                         return $obj;
  89                 }
  90                 return $class;
  91         }
  92
  93         /**
  94          * Get the action that will be executed, not necessarily the one passed
  95          * passed through the "action" request parameter. Actions disabled in
  96          * $wgActions will be replaced by "nosuchaction".
  97          *
  98          * @since 1.19
  99          * @param $context IContextSource
 100          * @return string: action name
 101          */
 102         public final static function getActionName( IContextSource $context ) {
 103                 global $wgActions;
 104
 105                 $request = $context->getRequest();
 106                 $actionName = $request->getVal( 'action', 'view' );
 107
 108                 // Check for disabled actions
 109                 if ( isset( $wgActions[$actionName] ) && $wgActions[$actionName] === false ) {
 110                         $actionName = 'nosuchaction';
 111                 }
 112
 113                 // Workaround for bug #20966: inability of IE to provide an action dependent
 114                 // on which submit button is clicked.
 115                 if ( $actionName === 'historysubmit' ) {
 116                         if ( $request->getBool( 'revisiondelete' ) ) {
 117                                 $actionName = 'revisiondelete';
 118                         } else {
 119                                 $actionName = 'view';
 120                         }
 121                 } elseif ( $actionName == 'editredlink' ) {
 122                         $actionName = 'edit';
 123                 }
 124
 125                 // Trying to get a WikiPage for NS_SPECIAL etc. will result
 126                 // in WikiPage::factory throwing "Invalid or virtual namespace -1 given."
 127                 // For SpecialPages et al, default to action=view.
 128                 if ( !$context->canUseWikiPage() ) {
 129                         return 'view';
 130                 }
 131
 132                 $action = Action::factory( $actionName, $context->getWikiPage() );
 133                 if ( $action instanceof Action ) {
 134                         return $action->getName();
 135                 }
 136
 137                 return 'nosuchaction';
 138         }
 139
 140         /**
 141          * Check if a given action is recognised, even if it's disabled
 142          *
 143          * @param $name String: name of an action
 144          * @return Bool
 145          */
 146         public final static function exists( $name ) {
 147                 return self::getClass( $name, array() ) !== null;
 148         }
 149
 150         /**
 151          * Get the IContextSource in use here
 152          * @return IContextSource
 153          */
 154         public final function getContext() {
 155                 if ( $this->context instanceof IContextSource ) {
 156                         return $this->context;
 157                 }
 158                 return $this->page->getContext();
 159         }
 160
 161         /**
 162          * Get the WebRequest being used for this instance
 163          *
 164          * @return WebRequest
 165          */
 166         public final function getRequest() {
 167                 return $this->getContext()->getRequest();
 168         }
 169
 170         /**
 171          * Get the OutputPage being used for this instance
 172          *
 173          * @return OutputPage
 174          */
 175         public final function getOutput() {
 176                 return $this->getContext()->getOutput();
 177         }
 178
 179         /**
 180          * Shortcut to get the User being used for this instance
 181          *
 182          * @return User
 183          */
 184         public final function getUser() {
 185                 return $this->getContext()->getUser();
 186         }
 187
 188         /**
 189          * Shortcut to get the Skin being used for this instance
 190          *
 191          * @return Skin
 192          */
 193         public final function getSkin() {
 194                 return $this->getContext()->getSkin();
 195         }
 196
 197         /**
 198          * Shortcut to get the user Language being used for this instance
 199          *
 200          * @return Language
 201          */
 202         public final function getLanguage() {
 203                 return $this->getContext()->getLanguage();
 204         }
 205
 206         /**
 207          * Shortcut to get the user Language being used for this instance
 208          *
 209          * @deprecated 1.19 Use getLanguage instead
 210          * @return Language
 211          */
 212         public final function getLang() {
 213                 wfDeprecated( __METHOD__, '1.19' );
 214                 return $this->getLanguage();
 215         }
 216
 217         /**
 218          * Shortcut to get the Title object from the page
 219          * @return Title
 220          */
 221         public final function getTitle() {
 222                 return $this->page->getTitle();
 223         }
 224
 225         /**
 226          * Get a Message object with context set
 227          * Parameters are the same as wfMessage()
 228          *
 229          * @return Message object
 230          */
 231         public final function msg() {
 232                 $params = func_get_args();
 233                 return call_user_func_array( array( $this->getContext(), 'msg' ), $params );
 234         }
 235
 236         /**
 237          * Protected constructor: use Action::factory( $action, $page ) to actually build
 238          * these things in the real world
 239          * @param $page Page
 240          * @param $context IContextSource
 241          */
 242         protected function __construct( Page $page, IContextSource $context = null ) {
 243                 $this->page = $page;
 244                 $this->context = $context;
 245         }
 246
 247         /**
 248          * Return the name of the action this object responds to
 249          * @return String lowercase
 250          */
 251         public abstract function getName();
 252
 253         /**
 254          * Get the permission required to perform this action.  Often, but not always,
 255          * the same as the action name
 256          * @return String|null
 257          */
 258         public function getRestriction() {
 259                 return null;
 260         }
 261
 262         /**
 263          * Checks if the given user (identified by an object) can perform this action.  Can be
 264          * overridden by sub-classes with more complicated permissions schemes.  Failures here
 265          * must throw subclasses of ErrorPageError
 266          *
 267          * @param $user User: the user to check, or null to use the context user
 268          * @throws ErrorPageError
 269          */
 270         protected function checkCanExecute( User $user ) {
 271                 $right = $this->getRestriction();
 272                 if ( $right !== null ) {
 273                         $errors = $this->getTitle()->getUserPermissionsErrors( $right, $user );
 274                         if ( count( $errors ) ) {
 275                                 throw new PermissionsError( $right, $errors );
 276                         }
 277                 }
 278
 279                 if ( $this->requiresUnblock() && $user->isBlocked() ) {
 280                         $block = $user->mBlock;
 281                         throw new UserBlockedError( $block );
 282                 }
 283
 284                 // This should be checked at the end so that the user won't think the
 285                 // error is only temporary when he also don't have the rights to execute
 286                 // this action
 287                 if ( $this->requiresWrite() && wfReadOnly() ) {
 288                         throw new ReadOnlyError();
 289                 }
 290         }
 291
 292         /**
 293          * Whether this action requires the wiki not to be locked
 294          * @return Bool
 295          */
 296         public function requiresWrite() {
 297                 return true;
 298         }
 299
 300         /**
 301          * Whether this action can still be executed by a blocked user
 302          * @return Bool
 303          */
 304         public function requiresUnblock() {
 305                 return true;
 306         }
 307
 308         /**
 309          * Set output headers for noindexing etc.  This function will not be called through
 310          * the execute() entry point, so only put UI-related stuff in here.
 311          */
 312         protected function setHeaders() {
 313                 $out = $this->getOutput();
 314                 $out->setRobotPolicy( "noindex,nofollow" );
 315                 $out->setPageTitle( $this->getPageTitle() );
 316                 $this->getOutput()->setSubtitle( $this->getDescription() );
 317                 $out->setArticleRelated( true );
 318         }
 319
 320         /**
 321          * Returns the name that goes in the \<h1\> page title
 322          *
 323          * @return String
 324          */
 325         protected function getPageTitle() {
 326                 return $this->getTitle()->getPrefixedText();
 327         }
 328
 329         /**
 330          * Returns the description that goes below the \<h1\> tag
 331          *
 332          * @return String
 333          */
 334         protected function getDescription() {
 335                 return wfMsgHtml( strtolower( $this->getName() ) );
 336         }
 337
 338         /**
 339          * The main action entry point.  Do all output for display and send it to the context
 340          * output.  Do not use globals $wgOut, $wgRequest, etc, in implementations; use
 341          * $this->getOutput(), etc.
 342          * @throws ErrorPageError
 343          */
 344         public abstract function show();
 345
 346         /**
 347          * Execute the action in a silent fashion: do not display anything or release any errors.
 348          * @return Bool whether execution was successful
 349          */
 350         public abstract function execute();
 351 }
 352
 353 abstract class FormAction extends Action {
 354
 355         /**
 356          * Get an HTMLForm descriptor array
 357          * @return Array
 358          */
 359         protected abstract function getFormFields();
 360
 361         /**
 362          * Add pre- or post-text to the form
 363          * @return String HTML which will be sent to $form->addPreText()
 364          */
 365         protected function preText() { return ''; }
 366
 367         /**
 368          * @return string
 369          */
 370         protected function postText() { return ''; }
 371
 372         /**
 373          * Play with the HTMLForm if you need to more substantially
 374          * @param $form HTMLForm
 375          */
 376         protected function alterForm( HTMLForm $form ) {}
 377
 378         /**
 379          * Get the HTMLForm to control behaviour
 380          * @return HTMLForm|null
 381          */
 382         protected function getForm() {
 383                 $this->fields = $this->getFormFields();
 384
 385                 // Give hooks a chance to alter the form, adding extra fields or text etc
 386                 wfRunHooks( 'ActionModifyFormFields', array( $this->getName(), &$this->fields, $this->page ) );
 387
 388                 $form = new HTMLForm( $this->fields, $this->getContext() );
 389                 $form->setSubmitCallback( array( $this, 'onSubmit' ) );
 390
 391                 // Retain query parameters (uselang etc)
 392                 $form->addHiddenField( 'action', $this->getName() ); // Might not be the same as the query string
 393                 $params = array_diff_key(
 394                         $this->getRequest()->getQueryValues(),
 395                         array( 'action' => null, 'title' => null )
 396                 );
 397                 $form->addHiddenField( 'redirectparams', wfArrayToCGI( $params ) );
 398
 399                 $form->addPreText( $this->preText() );
 400                 $form->addPostText( $this->postText() );
 401                 $this->alterForm( $form );
 402
 403                 // Give hooks a chance to alter the form, adding extra fields or text etc
 404                 wfRunHooks( 'ActionBeforeFormDisplay', array( $this->getName(), &$form, $this->page ) );
 405
 406                 return $form;
 407         }
 408
 409         /**
 410          * Process the form on POST submission.  If you return false from getFormFields(),
 411          * this will obviously never be reached.  If you don't want to do anything with the
 412          * form, just return false here
 413          * @param  $data Array
 414          * @return Bool|Array true for success, false for didn't-try, array of errors on failure
 415          */
 416         public abstract function onSubmit( $data );
 417
 418         /**
 419          * Do something exciting on successful processing of the form.  This might be to show
 420          * a confirmation message (watch, rollback, etc) or to redirect somewhere else (edit,
 421          * protect, etc).
 422          */
 423         public abstract function onSuccess();
 424
 425         /**
 426          * The basic pattern for actions is to display some sort of HTMLForm UI, maybe with
 427          * some stuff underneath (history etc); to do some processing on submission of that
 428          * form (delete, protect, etc) and to do something exciting on 'success', be that
 429          * display something new or redirect to somewhere.  Some actions have more exotic
 430          * behaviour, but that's what subclassing is for :D
 431          */
 432         public function show() {
 433                 $this->setHeaders();
 434
 435                 // This will throw exceptions if there's a problem
 436                 $this->checkCanExecute( $this->getUser() );
 437
 438                 $form = $this->getForm();
 439                 if ( $form->show() ) {
 440                         $this->onSuccess();
 441                 }
 442         }
 443
 444         /**
 445          * @see Action::execute()
 446          * @throws ErrorPageError
 447          * @param array|null $data
 448          * @param bool $captureErrors
 449          * @return bool
 450          */
 451         public function execute( array $data = null, $captureErrors = true ) {
 452                 try {
 453                         // Set a new context so output doesn't leak.
 454                         $this->context = clone $this->page->getContext();
 455
 456                         // This will throw exceptions if there's a problem
 457                         $this->checkCanExecute( $this->getUser() );
 458
 459                         $fields = array();
 460                         foreach ( $this->fields as $key => $params ) {
 461                                 if ( isset( $data[$key] ) ) {
 462                                         $fields[$key] = $data[$key];
 463                                 } elseif ( isset( $params['default'] ) ) {
 464                                         $fields[$key] = $params['default'];
 465                                 } else {
 466                                         $fields[$key] = null;
 467                                 }
 468                         }
 469                         $status = $this->onSubmit( $fields );
 470                         if ( $status === true ) {
 471                                 // This might do permanent stuff
 472                                 $this->onSuccess();
 473                                 return true;
 474                         } else {
 475                                 return false;
 476                         }
 477                 }
 478                 catch ( ErrorPageError $e ) {
 479                         if ( $captureErrors ) {
 480                                 return false;
 481                         } else {
 482                                 throw $e;
 483                         }
 484                 }
 485         }
 486 }
 487
 488 /**
 489  * Actions generally fall into two groups: the show-a-form-then-do-something-with-the-input
 490  * format (protect, delete, move, etc), and the just-do-something format (watch, rollback,
 491  * patrol, etc).
 492  */
 493 abstract class FormlessAction extends Action {
 494
 495         /**
 496          * Show something on GET request.
 497          * @return String|null will be added to the HTMLForm if present, or just added to the
 498          *     output if not.  Return null to not add anything
 499          */
 500         public abstract function onView();
 501
 502         /**
 503          * We don't want an HTMLForm
 504          */
 505         protected function getFormFields() {
 506                 return false;
 507         }
 508
 509         public function onSubmit( $data ) {
 510                 return false;
 511         }
 512
 513         public function onSuccess() {
 514                 return false;
 515         }
 516
 517         public function show() {
 518                 $this->setHeaders();
 519
 520                 // This will throw exceptions if there's a problem
 521                 $this->checkCanExecute( $this->getUser() );
 522
 523                 $this->getOutput()->addHTML( $this->onView() );
 524         }
 525
 526         /**
 527          * Execute the action silently, not giving any output.  Since these actions don't have
 528          * forms, they probably won't have any data, but some (eg rollback) may do
 529          * @param $data Array values that would normally be in the GET request
 530          * @param $captureErrors Bool whether to catch exceptions and just return false
 531          * @return Bool whether execution was successful
 532          */
 533         public function execute( array $data = null, $captureErrors = true ) {
 534                 try {
 535                         // Set a new context so output doesn't leak.
 536                         $this->context = clone $this->page->getContext();
 537                         if ( is_array( $data ) ) {
 538                                 $this->context->setRequest( new FauxRequest( $data, false ) );
 539                         }
 540
 541                         // This will throw exceptions if there's a problem
 542                         $this->checkCanExecute( $this->getUser() );
 543
 544                         $this->onView();
 545                         return true;
 546                 }
 547                 catch ( ErrorPageError $e ) {
 548                         if ( $captureErrors ) {
 549                                 return false;
 550                         } else {
 551                                 throw $e;
 552                         }
 553                 }
 554         }
 555 }