includes/Action.php

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