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