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