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(), $context );
 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                 } elseif ( $this->page instanceof Article ) {
 171                         // NOTE: $this->page can be a WikiPage, which does not have a context.
 172                         wfDebug( __METHOD__ . ': no context known, falling back to Article\'s context.' );
 173                         return $this->page->getContext();
 174                 }
 175
 176                 wfWarn( __METHOD__ . ': no context known, falling back to RequestContext::getMain().' );
 177                 return RequestContext::getMain();
 178         }
 179
 180         /**
 181          * Get the WebRequest being used for this instance
 182          *
 183          * @return WebRequest
 184          */
 185         final public function getRequest() {
 186                 return $this->getContext()->getRequest();
 187         }
 188
 189         /**
 190          * Get the OutputPage being used for this instance
 191          *
 192          * @return OutputPage
 193          */
 194         final public function getOutput() {
 195                 return $this->getContext()->getOutput();
 196         }
 197
 198         /**
 199          * Shortcut to get the User being used for this instance
 200          *
 201          * @return User
 202          */
 203         final public function getUser() {
 204                 return $this->getContext()->getUser();
 205         }
 206
 207         /**
 208          * Shortcut to get the Skin being used for this instance
 209          *
 210          * @return Skin
 211          */
 212         final public function getSkin() {
 213                 return $this->getContext()->getSkin();
 214         }
 215
 216         /**
 217          * Shortcut to get the user Language being used for this instance
 218          *
 219          * @return Language
 220          */
 221         final public function getLanguage() {
 222                 return $this->getContext()->getLanguage();
 223         }
 224
 225         /**
 226          * Shortcut to get the user Language being used for this instance
 227          *
 228          * @deprecated since 1.19 Use getLanguage instead
 229          * @return Language
 230          */
 231         final public function getLang() {
 232                 wfDeprecated( __METHOD__, '1.19' );
 233                 return $this->getLanguage();
 234         }
 235
 236         /**
 237          * Shortcut to get the Title object from the page
 238          * @return Title
 239          */
 240         final public function getTitle() {
 241                 return $this->page->getTitle();
 242         }
 243
 244         /**
 245          * Get a Message object with context set
 246          * Parameters are the same as wfMessage()
 247          *
 248          * @return Message object
 249          */
 250         final public function msg() {
 251                 $params = func_get_args();
 252                 return call_user_func_array( array( $this->getContext(), 'msg' ), $params );
 253         }
 254
 255         /**
 256          * Constructor.
 257          *
 258          * Only public since 1.21
 259          *
 260          * @param $page Page
 261          * @param $context IContextSource
 262          */
 263         public function __construct( Page $page, IContextSource $context = null ) {
 264                 if ( $context === null ) {
 265                         wfWarn( __METHOD__ . ' called without providing a Context object.' );
 266                         // NOTE: We could try to initialize $context using $page->getContext(),
 267                         //      if $page is an Article. That however seems to not work seamlessly.
 268                 }
 269
 270                 $this->page = $page;
 271                 $this->context = $context;
 272         }
 273
 274         /**
 275          * Return the name of the action this object responds to
 276          * @return String lowercase
 277          */
 278         abstract public function getName();
 279
 280         /**
 281          * Get the permission required to perform this action.  Often, but not always,
 282          * the same as the action name
 283          * @return String|null
 284          */
 285         public function getRestriction() {
 286                 return null;
 287         }
 288
 289         /**
 290          * Checks if the given user (identified by an object) can perform this action.  Can be
 291          * overridden by sub-classes with more complicated permissions schemes.  Failures here
 292          * must throw subclasses of ErrorPageError
 293          *
 294          * @param $user User: the user to check, or null to use the context user
 295          * @throws UserBlockedError|ReadOnlyError|PermissionsError
 296          * @return bool True on success
 297          */
 298         protected function checkCanExecute( User $user ) {
 299                 $right = $this->getRestriction();
 300                 if ( $right !== null ) {
 301                         $errors = $this->getTitle()->getUserPermissionsErrors( $right, $user );
 302                         if ( count( $errors ) ) {
 303                                 throw new PermissionsError( $right, $errors );
 304                         }
 305                 }
 306
 307                 if ( $this->requiresUnblock() && $user->isBlocked() ) {
 308                         $block = $user->getBlock();
 309                         throw new UserBlockedError( $block );
 310                 }
 311
 312                 // This should be checked at the end so that the user won't think the
 313                 // error is only temporary when he also don't have the rights to execute
 314                 // this action
 315                 if ( $this->requiresWrite() && wfReadOnly() ) {
 316                         throw new ReadOnlyError();
 317                 }
 318                 return true;
 319         }
 320
 321         /**
 322          * Whether this action requires the wiki not to be locked
 323          * @return Bool
 324          */
 325         public function requiresWrite() {
 326                 return true;
 327         }
 328
 329         /**
 330          * Whether this action can still be executed by a blocked user
 331          * @return Bool
 332          */
 333         public function requiresUnblock() {
 334                 return true;
 335         }
 336
 337         /**
 338          * Set output headers for noindexing etc.  This function will not be called through
 339          * the execute() entry point, so only put UI-related stuff in here.
 340          */
 341         protected function setHeaders() {
 342                 $out = $this->getOutput();
 343                 $out->setRobotPolicy( "noindex,nofollow" );
 344                 $out->setPageTitle( $this->getPageTitle() );
 345                 $this->getOutput()->setSubtitle( $this->getDescription() );
 346                 $out->setArticleRelated( true );
 347         }
 348
 349         /**
 350          * Returns the name that goes in the \<h1\> page title
 351          *
 352          * @return String
 353          */
 354         protected function getPageTitle() {
 355                 return $this->getTitle()->getPrefixedText();
 356         }
 357
 358         /**
 359          * Returns the description that goes below the \<h1\> tag
 360          *
 361          * @return String
 362          */
 363         protected function getDescription() {
 364                 return $this->msg( strtolower( $this->getName() ) )->escaped();
 365         }
 366
 367         /**
 368          * The main action entry point.  Do all output for display and send it to the context
 369          * output.  Do not use globals $wgOut, $wgRequest, etc, in implementations; use
 370          * $this->getOutput(), etc.
 371          * @throws ErrorPageError
 372          */
 373         abstract public function show();
 374
 375         /**
 376          * Execute the action in a silent fashion: do not display anything or release any errors.
 377          * @return Bool whether execution was successful
 378          */
 379         abstract public function execute();
 380 }
 381
 382 /**
 383  * An action which shows a form and does something based on the input from the form
 384  */
 385 abstract class FormAction extends Action {
 386
 387         /**
 388          * Get an HTMLForm descriptor array
 389          * @return Array
 390          */
 391         abstract protected function getFormFields();
 392
 393         /**
 394          * Add pre- or post-text to the form
 395          * @return String HTML which will be sent to $form->addPreText()
 396          */
 397         protected function preText() {
 398                 return '';
 399         }
 400
 401         /**
 402          * @return string
 403          */
 404         protected function postText() {
 405                 return '';
 406         }
 407
 408         /**
 409          * Play with the HTMLForm if you need to more substantially
 410          * @param $form HTMLForm
 411          */
 412         protected function alterForm( HTMLForm $form ) {
 413         }
 414
 415         /**
 416          * Get the HTMLForm to control behavior
 417          * @return HTMLForm|null
 418          */
 419         protected function getForm() {
 420                 $this->fields = $this->getFormFields();
 421
 422                 // Give hooks a chance to alter the form, adding extra fields or text etc
 423                 wfRunHooks( 'ActionModifyFormFields', array( $this->getName(), &$this->fields, $this->page ) );
 424
 425                 $form = new HTMLForm( $this->fields, $this->getContext(), $this->getName() );
 426                 $form->setSubmitCallback( array( $this, 'onSubmit' ) );
 427
 428                 // Retain query parameters (uselang etc)
 429                 $form->addHiddenField( 'action', $this->getName() ); // Might not be the same as the query string
 430                 $params = array_diff_key(
 431                         $this->getRequest()->getQueryValues(),
 432                         array( 'action' => null, 'title' => null )
 433                 );
 434                 $form->addHiddenField( 'redirectparams', wfArrayToCgi( $params ) );
 435
 436                 $form->addPreText( $this->preText() );
 437                 $form->addPostText( $this->postText() );
 438                 $this->alterForm( $form );
 439
 440                 // Give hooks a chance to alter the form, adding extra fields or text etc
 441                 wfRunHooks( 'ActionBeforeFormDisplay', array( $this->getName(), &$form, $this->page ) );
 442
 443                 return $form;
 444         }
 445
 446         /**
 447          * Process the form on POST submission.  If you return false from getFormFields(),
 448          * this will obviously never be reached.  If you don't want to do anything with the
 449          * form, just return false here
 450          * @param  $data Array
 451          * @return Bool|Array true for success, false for didn't-try, array of errors on failure
 452          */
 453         abstract public function onSubmit( $data );
 454
 455         /**
 456          * Do something exciting on successful processing of the form.  This might be to show
 457          * a confirmation message (watch, rollback, etc) or to redirect somewhere else (edit,
 458          * protect, etc).
 459          */
 460         abstract public function onSuccess();
 461
 462         /**
 463          * The basic pattern for actions is to display some sort of HTMLForm UI, maybe with
 464          * some stuff underneath (history etc); to do some processing on submission of that
 465          * form (delete, protect, etc) and to do something exciting on 'success', be that
 466          * display something new or redirect to somewhere.  Some actions have more exotic
 467          * behavior, but that's what subclassing is for :D
 468          */
 469         public function show() {
 470                 $this->setHeaders();
 471
 472                 // This will throw exceptions if there's a problem
 473                 $this->checkCanExecute( $this->getUser() );
 474
 475                 $form = $this->getForm();
 476                 if ( $form->show() ) {
 477                         $this->onSuccess();
 478                 }
 479         }
 480
 481         /**
 482          * @see Action::execute()
 483          *
 484          * @param $data array|null
 485          * @param $captureErrors bool
 486          * @throws ErrorPageError|Exception
 487          * @return bool
 488          */
 489         public function execute( array $data = null, $captureErrors = true ) {
 490                 try {
 491                         // Set a new context so output doesn't leak.
 492                         $this->context = clone $this->getContext();
 493
 494                         // This will throw exceptions if there's a problem
 495                         $this->checkCanExecute( $this->getUser() );
 496
 497                         $fields = array();
 498                         foreach ( $this->fields as $key => $params ) {
 499                                 if ( isset( $data[$key] ) ) {
 500                                         $fields[$key] = $data[$key];
 501                                 } elseif ( isset( $params['default'] ) ) {
 502                                         $fields[$key] = $params['default'];
 503                                 } else {
 504                                         $fields[$key] = null;
 505                                 }
 506                         }
 507                         $status = $this->onSubmit( $fields );
 508                         if ( $status === true ) {
 509                                 // This might do permanent stuff
 510                                 $this->onSuccess();
 511                                 return true;
 512                         } else {
 513                                 return false;
 514                         }
 515                 }
 516                 catch ( ErrorPageError $e ) {
 517                         if ( $captureErrors ) {
 518                                 return false;
 519                         } else {
 520                                 throw $e;
 521                         }
 522                 }
 523         }
 524 }
 525
 526 /**
 527  * An action which just does something, without showing a form first.
 528  */
 529 abstract class FormlessAction extends Action {
 530
 531         /**
 532          * Show something on GET request.
 533          * @return String|null will be added to the HTMLForm if present, or just added to the
 534          *     output if not.  Return null to not add anything
 535          */
 536         abstract public function onView();
 537
 538         /**
 539          * We don't want an HTMLForm
 540          * @return bool
 541          */
 542         protected function getFormFields() {
 543                 return false;
 544         }
 545
 546         /**
 547          * @param $data Array
 548          * @return bool
 549          */
 550         public function onSubmit( $data ) {
 551                 return false;
 552         }
 553
 554         /**
 555          * @return bool
 556          */
 557         public function onSuccess() {
 558                 return false;
 559         }
 560
 561         public function show() {
 562                 $this->setHeaders();
 563
 564                 // This will throw exceptions if there's a problem
 565                 $this->checkCanExecute( $this->getUser() );
 566
 567                 $this->getOutput()->addHTML( $this->onView() );
 568         }
 569
 570         /**
 571          * Execute the action silently, not giving any output.  Since these actions don't have
 572          * forms, they probably won't have any data, but some (eg rollback) may do
 573          * @param array $data values that would normally be in the GET request
 574          * @param bool $captureErrors whether to catch exceptions and just return false
 575          * @throws ErrorPageError|Exception
 576          * @return Bool whether execution was successful
 577          */
 578         public function execute( array $data = null, $captureErrors = true ) {
 579                 try {
 580                         // Set a new context so output doesn't leak.
 581                         $this->context = clone $this->getContext();
 582                         if ( is_array( $data ) ) {
 583                                 $this->context->setRequest( new FauxRequest( $data, false ) );
 584                         }
 585
 586                         // This will throw exceptions if there's a problem
 587                         $this->checkCanExecute( $this->getUser() );
 588
 589                         $this->onView();
 590                         return true;
 591                 }
 592                 catch ( ErrorPageError $e ) {
 593                         if ( $captureErrors ) {
 594                                 return false;
 595                         } else {
 596                                 throw $e;
 597                         }
 598                 }
 599         }
 600 }