includes/Action.php

   1 <?php
   2 /**
   3  * Base classes for actions done on pages.
   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
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
  18  *
  19  * @file
  20  */
  21
  22 /**
  23  * @defgroup Actions Action done on pages
  24  */
  25
  26 /**
  27  * Actions are things which can be done to pages (edit, delete, rollback, etc).  They
  28  * are distinct from Special Pages because an action must apply to exactly one page.
  29  *
  30  * To add an action in an extension, create a subclass of Action, and add the key to
  31  * $wgActions.  There is also the deprecated UnknownAction hook
  32  *
  33  * Actions generally fall into two groups: the show-a-form-then-do-something-with-the-input
  34  * format (protect, delete, move, etc), and the just-do-something format (watch, rollback,
  35  * patrol, etc). The FormAction and FormlessAction classes represent these two groups.
  36  */
  37 abstract class Action {
  38
  39         /**
  40          * Page on which we're performing the action
  41          * @var WikiPage|Article|ImagePage|CategoryPage|Page $page
  42          */
  43         protected $page;
  44
  45         /**
  46          * IContextSource if specified; otherwise we'll use the Context from the Page
  47          * @var IContextSource $context
  48          */
  49         protected $context;
  50
  51         /**
  52          * The fields used to create the HTMLForm
  53          * @var Array $fields
  54          */
  55         protected $fields;
  56
  57         /**
  58          * Get the Action subclass which should be used to handle this action, false if
  59          * the action is disabled, or null if it's not recognised
  60          * @param $action String
  61          * @param $overrides Array
  62          * @return bool|null|string|callable
  63          */
  64         final private static function getClass( $action, array $overrides ) {
  65                 global $wgActions;
  66                 $action = strtolower( $action );
  67
  68                 if ( !isset( $wgActions[$action] ) ) {
  69                         return null;
  70                 }
  71
  72                 if ( $wgActions[$action] === false ) {
  73                         return false;
  74                 } elseif ( $wgActions[$action] === true && isset( $overrides[$action] ) ) {
  75                         return $overrides[$action];
  76                 } elseif ( $wgActions[$action] === true ) {
  77                         return ucfirst( $action ) . 'Action';
  78                 } else {
  79                         return $wgActions[$action];
  80                 }
  81         }
  82
  83         /**
  84          * Get an appropriate Action subclass for the given action
  85          * @param $action String
  86          * @param $page Page
  87          * @param $context IContextSource
  88          * @return Action|bool|null false if the action is disabled, null
  89          *     if it is not recognised
  90          */
  91         final public static function factory( $action, Page $page, IContextSource $context = null ) {
  92                 $classOrCallable = self::getClass( $action, $page->getActionOverrides() );
  93
  94                 if ( is_string( $classOrCallable ) ) {
  95                         $obj = new $classOrCallable( $page, $context );
  96                         return $obj;
  97                 }
  98
  99                 if ( is_callable( $classOrCallable ) ) {
 100                         return call_user_func_array( $classOrCallable, array( $page, $context ) );
 101                 }
 102
 103                 return $classOrCallable;
 104         }
 105
 106         /**
 107          * Get the action that will be executed, not necessarily the one passed
 108          * passed through the "action" request parameter. Actions disabled in
 109          * $wgActions will be replaced by "nosuchaction".
 110          *
 111          * @since 1.19
 112          * @param $context IContextSource
 113          * @return string: action name
 114          */
 115         final public static function getActionName( IContextSource $context ) {
 116                 global $wgActions;
 117
 118                 $request = $context->getRequest();
 119                 $actionName = $request->getVal( 'action', 'view' );
 120
 121                 // Check for disabled actions
 122                 if ( isset( $wgActions[$actionName] ) && $wgActions[$actionName] === false ) {
 123                         $actionName = 'nosuchaction';
 124                 }
 125
 126                 // Workaround for bug #20966: inability of IE to provide an action dependent
 127                 // on which submit button is clicked.
 128                 if ( $actionName === 'historysubmit' ) {
 129                         if ( $request->getBool( 'revisiondelete' ) ) {
 130                                 $actionName = 'revisiondelete';
 131                         } else {
 132                                 $actionName = 'view';
 133                         }
 134                 } elseif ( $actionName == 'editredlink' ) {
 135                         $actionName = 'edit';
 136                 }
 137
 138                 // Trying to get a WikiPage for NS_SPECIAL etc. will result
 139                 // in WikiPage::factory throwing "Invalid or virtual namespace -1 given."
 140                 // For SpecialPages et al, default to action=view.
 141                 if ( !$context->canUseWikiPage() ) {
 142                         return 'view';
 143                 }
 144
 145                 $action = Action::factory( $actionName, $context->getWikiPage() );
 146                 if ( $action instanceof Action ) {
 147                         return $action->getName();
 148                 }
 149
 150                 return 'nosuchaction';
 151         }
 152
 153         /**
 154          * Check if a given action is recognised, even if it's disabled
 155          *
 156          * @param string $name name of an action
 157          * @return Bool
 158          */
 159         final public static function exists( $name ) {
 160                 return self::getClass( $name, array() ) !== null;
 161         }
 162
 163         /**
 164          * Get the IContextSource in use here
 165          * @return IContextSource
 166          */
 167         final public function getContext() {
 168                 if ( $this->context instanceof IContextSource ) {
 169                         return $this->context;
 170                 }
 171                 return $this->page->getContext();
 172         }
 173
 174         /**
 175          * Get the WebRequest being used for this instance
 176          *
 177          * @return WebRequest
 178          */
 179         final public function getRequest() {
 180                 return $this->getContext()->getRequest();
 181         }
 182
 183         /**
 184          * Get the OutputPage being used for this instance
 185          *
 186          * @return OutputPage
 187          */
 188         final public function getOutput() {
 189                 return $this->getContext()->getOutput();
 190         }
 191
 192         /**
 193          * Shortcut to get the User being used for this instance
 194          *
 195          * @return User
 196          */
 197         final public function getUser() {
 198                 return $this->getContext()->getUser();
 199         }
 200
 201         /**
 202          * Shortcut to get the Skin being used for this instance
 203          *
 204          * @return Skin
 205          */
 206         final public function getSkin() {
 207                 return $this->getContext()->getSkin();
 208         }
 209
 210         /**
 211          * Shortcut to get the user Language being used for this instance
 212          *
 213          * @return Language
 214          */
 215         final public function getLanguage() {
 216                 return $this->getContext()->getLanguage();
 217         }
 218
 219         /**
 220          * Shortcut to get the user Language being used for this instance
 221          *
 222          * @deprecated since 1.19 Use getLanguage instead
 223          * @return Language
 224          */
 225         final public function getLang() {
 226                 wfDeprecated( __METHOD__, '1.19' );
 227                 return $this->getLanguage();
 228         }
 229
 230         /**
 231          * Shortcut to get the Title object from the page
 232          * @return Title
 233          */
 234         final public function getTitle() {
 235                 return $this->page->getTitle();
 236         }
 237
 238         /**
 239          * Get a Message object with context set
 240          * Parameters are the same as wfMessage()
 241          *
 242          * @return Message object
 243          */
 244         final public function msg() {
 245                 $params = func_get_args();
 246                 return call_user_func_array( array( $this->getContext(), 'msg' ), $params );
 247         }
 248
 249         /**
 250          * Constructor.
 251          *
 252          * Only public since 1.21
 253          *
 254          * @param $page Page
 255          * @param $context IContextSource
 256          */
 257         public function __construct( Page $page, IContextSource $context = null ) {
 258                 $this->page = $page;
 259                 $this->context = $context;
 260         }
 261
 262         /**
 263          * Return the name of the action this object responds to
 264          * @return String lowercase
 265          */
 266         abstract public function getName();
 267
 268         /**
 269          * Get the permission required to perform this action.  Often, but not always,
 270          * the same as the action name
 271          * @return String|null
 272          */
 273         public function getRestriction() {
 274                 return null;
 275         }
 276
 277         /**
 278          * Checks if the given user (identified by an object) can perform this action.  Can be
 279          * overridden by sub-classes with more complicated permissions schemes.  Failures here
 280          * must throw subclasses of ErrorPageError
 281          *
 282          * @param $user User: the user to check, or null to use the context user
 283          * @throws UserBlockedError|ReadOnlyError|PermissionsError
 284          * @return bool True on success
 285          */
 286         protected function checkCanExecute( User $user ) {
 287                 $right = $this->getRestriction();
 288                 if ( $right !== null ) {
 289                         $errors = $this->getTitle()->getUserPermissionsErrors( $right, $user );
 290                         if ( count( $errors ) ) {
 291                                 throw new PermissionsError( $right, $errors );
 292                         }
 293                 }
 294
 295                 if ( $this->requiresUnblock() && $user->isBlocked() ) {
 296                         $block = $user->getBlock();
 297                         throw new UserBlockedError( $block );
 298                 }
 299
 300                 // This should be checked at the end so that the user won't think the
 301                 // error is only temporary when he also don't have the rights to execute
 302                 // this action
 303                 if ( $this->requiresWrite() && wfReadOnly() ) {
 304                         throw new ReadOnlyError();
 305                 }
 306                 return true;
 307         }
 308
 309         /**
 310          * Whether this action requires the wiki not to be locked
 311          * @return Bool
 312          */
 313         public function requiresWrite() {
 314                 return true;
 315         }
 316
 317         /**
 318          * Whether this action can still be executed by a blocked user
 319          * @return Bool
 320          */
 321         public function requiresUnblock() {
 322                 return true;
 323         }
 324
 325         /**
 326          * Set output headers for noindexing etc.  This function will not be called through
 327          * the execute() entry point, so only put UI-related stuff in here.
 328          */
 329         protected function setHeaders() {
 330                 $out = $this->getOutput();
 331                 $out->setRobotPolicy( "noindex,nofollow" );
 332                 $out->setPageTitle( $this->getPageTitle() );
 333                 $this->getOutput()->setSubtitle( $this->getDescription() );
 334                 $out->setArticleRelated( true );
 335         }
 336
 337         /**
 338          * Returns the name that goes in the \<h1\> page title
 339          *
 340          * @return String
 341          */
 342         protected function getPageTitle() {
 343                 return $this->getTitle()->getPrefixedText();
 344         }
 345
 346         /**
 347          * Returns the description that goes below the \<h1\> tag
 348          *
 349          * @return String
 350          */
 351         protected function getDescription() {
 352                 return $this->msg( strtolower( $this->getName() ) )->escaped();
 353         }
 354
 355         /**
 356          * The main action entry point.  Do all output for display and send it to the context
 357          * output.  Do not use globals $wgOut, $wgRequest, etc, in implementations; use
 358          * $this->getOutput(), etc.
 359          * @throws ErrorPageError
 360          */
 361         abstract public function show();
 362
 363         /**
 364          * Execute the action in a silent fashion: do not display anything or release any errors.
 365          * @return Bool whether execution was successful
 366          */
 367         abstract public function execute();
 368 }
 369
 370 /**
 371  * An action which shows a form and does something based on the input from the form
 372  */
 373 abstract class FormAction extends Action {
 374
 375         /**
 376          * Get an HTMLForm descriptor array
 377          * @return Array
 378          */
 379         abstract protected function getFormFields();
 380
 381         /**
 382          * Add pre- or post-text to the form
 383          * @return String HTML which will be sent to $form->addPreText()
 384          */
 385         protected function preText() {
 386                 return '';
 387         }
 388
 389         /**
 390          * @return string
 391          */
 392         protected function postText() {
 393                 return '';
 394         }
 395
 396         /**
 397          * Play with the HTMLForm if you need to more substantially
 398          * @param $form HTMLForm
 399          */
 400         protected function alterForm( HTMLForm $form ) {
 401         }
 402
 403         /**
 404          * Get the HTMLForm to control behavior
 405          * @return HTMLForm|null
 406          */
 407         protected function getForm() {
 408                 $this->fields = $this->getFormFields();
 409
 410                 // Give hooks a chance to alter the form, adding extra fields or text etc
 411                 wfRunHooks( 'ActionModifyFormFields', array( $this->getName(), &$this->fields, $this->page ) );
 412
 413                 $form = new HTMLForm( $this->fields, $this->getContext(), $this->getName() );
 414                 $form->setSubmitCallback( array( $this, 'onSubmit' ) );
 415
 416                 // Retain query parameters (uselang etc)
 417                 $form->addHiddenField( 'action', $this->getName() ); // Might not be the same as the query string
 418                 $params = array_diff_key(
 419                         $this->getRequest()->getQueryValues(),
 420                         array( 'action' => null, 'title' => null )
 421                 );
 422                 $form->addHiddenField( 'redirectparams', wfArrayToCgi( $params ) );
 423
 424                 $form->addPreText( $this->preText() );
 425                 $form->addPostText( $this->postText() );
 426                 $this->alterForm( $form );
 427
 428                 // Give hooks a chance to alter the form, adding extra fields or text etc
 429                 wfRunHooks( 'ActionBeforeFormDisplay', array( $this->getName(), &$form, $this->page ) );
 430
 431                 return $form;
 432         }
 433
 434         /**
 435          * Process the form on POST submission.  If you return false from getFormFields(),
 436          * this will obviously never be reached.  If you don't want to do anything with the
 437          * form, just return false here
 438          * @param  $data Array
 439          * @return Bool|Array true for success, false for didn't-try, array of errors on failure
 440          */
 441         abstract public function onSubmit( $data );
 442
 443         /**
 444          * Do something exciting on successful processing of the form.  This might be to show
 445          * a confirmation message (watch, rollback, etc) or to redirect somewhere else (edit,
 446          * protect, etc).
 447          */
 448         abstract public function onSuccess();
 449
 450         /**
 451          * The basic pattern for actions is to display some sort of HTMLForm UI, maybe with
 452          * some stuff underneath (history etc); to do some processing on submission of that
 453          * form (delete, protect, etc) and to do something exciting on 'success', be that
 454          * display something new or redirect to somewhere.  Some actions have more exotic
 455          * behavior, but that's what subclassing is for :D
 456          */
 457         public function show() {
 458                 $this->setHeaders();
 459
 460                 // This will throw exceptions if there's a problem
 461                 $this->checkCanExecute( $this->getUser() );
 462
 463                 $form = $this->getForm();
 464                 if ( $form->show() ) {
 465                         $this->onSuccess();
 466                 }
 467         }
 468
 469         /**
 470          * @see Action::execute()
 471          *
 472          * @param $data array|null
 473          * @param $captureErrors bool
 474          * @throws ErrorPageError|Exception
 475          * @return bool
 476          */
 477         public function execute( array $data = null, $captureErrors = true ) {
 478                 try {
 479                         // Set a new context so output doesn't leak.
 480                         $this->context = clone $this->page->getContext();
 481
 482                         // This will throw exceptions if there's a problem
 483                         $this->checkCanExecute( $this->getUser() );
 484
 485                         $fields = array();
 486                         foreach ( $this->fields as $key => $params ) {
 487                                 if ( isset( $data[$key] ) ) {
 488                                         $fields[$key] = $data[$key];
 489                                 } elseif ( isset( $params['default'] ) ) {
 490                                         $fields[$key] = $params['default'];
 491                                 } else {
 492                                         $fields[$key] = null;
 493                                 }
 494                         }
 495                         $status = $this->onSubmit( $fields );
 496                         if ( $status === true ) {
 497                                 // This might do permanent stuff
 498                                 $this->onSuccess();
 499                                 return true;
 500                         } else {
 501                                 return false;
 502                         }
 503                 }
 504                 catch ( ErrorPageError $e ) {
 505                         if ( $captureErrors ) {
 506                                 return false;
 507                         } else {
 508                                 throw $e;
 509                         }
 510                 }
 511         }
 512 }
 513
 514 /**
 515  * An action which just does something, without showing a form first.
 516  */
 517 abstract class FormlessAction extends Action {
 518
 519         /**
 520          * Show something on GET request.
 521          * @return String|null will be added to the HTMLForm if present, or just added to the
 522          *     output if not.  Return null to not add anything
 523          */
 524         abstract public function onView();
 525
 526         /**
 527          * We don't want an HTMLForm
 528          * @return bool
 529          */
 530         protected function getFormFields() {
 531                 return false;
 532         }
 533
 534         /**
 535          * @param $data Array
 536          * @return bool
 537          */
 538         public function onSubmit( $data ) {
 539                 return false;
 540         }
 541
 542         /**
 543          * @return bool
 544          */
 545         public function onSuccess() {
 546                 return false;
 547         }
 548
 549         public function show() {
 550                 $this->setHeaders();
 551
 552                 // This will throw exceptions if there's a problem
 553                 $this->checkCanExecute( $this->getUser() );
 554
 555                 $this->getOutput()->addHTML( $this->onView() );
 556         }
 557
 558         /**
 559          * Execute the action silently, not giving any output.  Since these actions don't have
 560          * forms, they probably won't have any data, but some (eg rollback) may do
 561          * @param array $data values that would normally be in the GET request
 562          * @param bool $captureErrors whether to catch exceptions and just return false
 563          * @throws ErrorPageError|Exception
 564          * @return Bool whether execution was successful
 565          */
 566         public function execute( array $data = null, $captureErrors = true ) {
 567                 try {
 568                         // Set a new context so output doesn't leak.
 569                         $this->context = clone $this->page->getContext();
 570                         if ( is_array( $data ) ) {
 571                                 $this->context->setRequest( new FauxRequest( $data, false ) );
 572                         }
 573
 574                         // This will throw exceptions if there's a problem
 575                         $this->checkCanExecute( $this->getUser() );
 576
 577                         $this->onView();
 578                         return true;
 579                 }
 580                 catch ( ErrorPageError $e ) {
 581                         if ( $captureErrors ) {
 582                                 return false;
 583                         } else {
 584                                 throw $e;
 585                         }
 586                 }
 587         }
 588 }