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