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
  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                 $class = self::getClass( $action, $page->getActionOverrides() );
  93                 if ( $class ) {
  94                         $obj = new $class( $page, $context );
  95                         return $obj;
  96                 }
  97                 return $class;
  98         }
  99
 100         /**
 101          * Get the action that will be executed, not necessarily the one passed
 102          * passed through the "action" request parameter. Actions disabled in
 103          * $wgActions will be replaced by "nosuchaction".
 104          *
 105          * @since 1.19
 106          * @param $context IContextSource
 107          * @return string: action name
 108          */
 109         final public static function getActionName( IContextSource $context ) {
 110                 global $wgActions;
 111
 112                 $request = $context->getRequest();
 113                 $actionName = $request->getVal( 'action', 'view' );
 114
 115                 // Check for disabled actions
 116                 if ( isset( $wgActions[$actionName] ) && $wgActions[$actionName] === false ) {
 117                         $actionName = 'nosuchaction';
 118                 }
 119
 120                 // Workaround for bug #20966: inability of IE to provide an action dependent
 121                 // on which submit button is clicked.
 122                 if ( $actionName === 'historysubmit' ) {
 123                         if ( $request->getBool( 'revisiondelete' ) ) {
 124                                 $actionName = 'revisiondelete';
 125                         } else {
 126                                 $actionName = 'view';
 127                         }
 128                 } elseif ( $actionName == 'editredlink' ) {
 129                         $actionName = 'edit';
 130                 }
 131
 132                 // Trying to get a WikiPage for NS_SPECIAL etc. will result
 133                 // in WikiPage::factory throwing "Invalid or virtual namespace -1 given."
 134                 // For SpecialPages et al, default to action=view.
 135                 if ( !$context->canUseWikiPage() ) {
 136                         return 'view';
 137                 }
 138
 139                 $action = Action::factory( $actionName, $context->getWikiPage() );
 140                 if ( $action instanceof Action ) {
 141                         return $action->getName();
 142                 }
 143
 144                 return 'nosuchaction';
 145         }
 146
 147         /**
 148          * Check if a given action is recognised, even if it's disabled
 149          *
 150          * @param string $name name of an action
 151          * @return Bool
 152          */
 153         final public static function exists( $name ) {
 154                 return self::getClass( $name, array() ) !== null;
 155         }
 156
 157         /**
 158          * Get the IContextSource in use here
 159          * @return IContextSource
 160          */
 161         final public function getContext() {
 162                 if ( $this->context instanceof IContextSource ) {
 163                         return $this->context;
 164                 }
 165                 return $this->page->getContext();
 166         }
 167
 168         /**
 169          * Get the WebRequest being used for this instance
 170          *
 171          * @return WebRequest
 172          */
 173         final public function getRequest() {
 174                 return $this->getContext()->getRequest();
 175         }
 176
 177         /**
 178          * Get the OutputPage being used for this instance
 179          *
 180          * @return OutputPage
 181          */
 182         final public function getOutput() {
 183                 return $this->getContext()->getOutput();
 184         }
 185
 186         /**
 187          * Shortcut to get the User being used for this instance
 188          *
 189          * @return User
 190          */
 191         final public function getUser() {
 192                 return $this->getContext()->getUser();
 193         }
 194
 195         /**
 196          * Shortcut to get the Skin being used for this instance
 197          *
 198          * @return Skin
 199          */
 200         final public function getSkin() {
 201                 return $this->getContext()->getSkin();
 202         }
 203
 204         /**
 205          * Shortcut to get the user Language being used for this instance
 206          *
 207          * @return Language
 208          */
 209         final public function getLanguage() {
 210                 return $this->getContext()->getLanguage();
 211         }
 212
 213         /**
 214          * Shortcut to get the user Language being used for this instance
 215          *
 216          * @deprecated 1.19 Use getLanguage instead
 217          * @return Language
 218          */
 219         final public function getLang() {
 220                 wfDeprecated( __METHOD__, '1.19' );
 221                 return $this->getLanguage();
 222         }
 223
 224         /**
 225          * Shortcut to get the Title object from the page
 226          * @return Title
 227          */
 228         final public function getTitle() {
 229                 return $this->page->getTitle();
 230         }
 231
 232         /**
 233          * Get a Message object with context set
 234          * Parameters are the same as wfMessage()
 235          *
 236          * @return Message object
 237          */
 238         final public function msg() {
 239                 $params = func_get_args();
 240                 return call_user_func_array( array( $this->getContext(), 'msg' ), $params );
 241         }
 242
 243         /**
 244          * Protected constructor: use Action::factory( $action, $page ) to actually build
 245          * these things in the real world
 246          * @param $page Page
 247          * @param $context IContextSource
 248          */
 249         protected function __construct( Page $page, IContextSource $context = null ) {
 250                 $this->page = $page;
 251                 $this->context = $context;
 252         }
 253
 254         /**
 255          * Return the name of the action this object responds to
 256          * @return String lowercase
 257          */
 258         abstract public function getName();
 259
 260         /**
 261          * Get the permission required to perform this action.  Often, but not always,
 262          * the same as the action name
 263          * @return String|null
 264          */
 265         public function getRestriction() {
 266                 return null;
 267         }
 268
 269         /**
 270          * Checks if the given user (identified by an object) can perform this action.  Can be
 271          * overridden by sub-classes with more complicated permissions schemes.  Failures here
 272          * must throw subclasses of ErrorPageError
 273          *
 274          * @param $user User: the user to check, or null to use the context user
 275          * @throws UserBlockedError|ReadOnlyError|PermissionsError
 276          * @return bool True on success
 277          */
 278         protected function checkCanExecute( User $user ) {
 279                 $right = $this->getRestriction();
 280                 if ( $right !== null ) {
 281                         $errors = $this->getTitle()->getUserPermissionsErrors( $right, $user );
 282                         if ( count( $errors ) ) {
 283                                 throw new PermissionsError( $right, $errors );
 284                         }
 285                 }
 286
 287                 if ( $this->requiresUnblock() && $user->isBlocked() ) {
 288                         $block = $user->getBlock();
 289                         throw new UserBlockedError( $block );
 290                 }
 291
 292                 // This should be checked at the end so that the user won't think the
 293                 // error is only temporary when he also don't have the rights to execute
 294                 // this action
 295                 if ( $this->requiresWrite() && wfReadOnly() ) {
 296                         throw new ReadOnlyError();
 297                 }
 298                 return true;
 299         }
 300
 301         /**
 302          * Whether this action requires the wiki not to be locked
 303          * @return Bool
 304          */
 305         public function requiresWrite() {
 306                 return true;
 307         }
 308
 309         /**
 310          * Whether this action can still be executed by a blocked user
 311          * @return Bool
 312          */
 313         public function requiresUnblock() {
 314                 return true;
 315         }
 316
 317         /**
 318          * Set output headers for noindexing etc.  This function will not be called through
 319          * the execute() entry point, so only put UI-related stuff in here.
 320          */
 321         protected function setHeaders() {
 322                 $out = $this->getOutput();
 323                 $out->setRobotPolicy( "noindex,nofollow" );
 324                 $out->setPageTitle( $this->getPageTitle() );
 325                 $this->getOutput()->setSubtitle( $this->getDescription() );
 326                 $out->setArticleRelated( true );
 327         }
 328
 329         /**
 330          * Returns the name that goes in the \<h1\> page title
 331          *
 332          * @return String
 333          */
 334         protected function getPageTitle() {
 335                 return $this->getTitle()->getPrefixedText();
 336         }
 337
 338         /**
 339          * Returns the description that goes below the \<h1\> tag
 340          *
 341          * @return String
 342          */
 343         protected function getDescription() {
 344                 return $this->msg( strtolower( $this->getName() ) )->escaped();
 345         }
 346
 347         /**
 348          * The main action entry point.  Do all output for display and send it to the context
 349          * output.  Do not use globals $wgOut, $wgRequest, etc, in implementations; use
 350          * $this->getOutput(), etc.
 351          * @throws ErrorPageError
 352          */
 353         abstract public function show();
 354
 355         /**
 356          * Execute the action in a silent fashion: do not display anything or release any errors.
 357          * @return Bool whether execution was successful
 358          */
 359         abstract public function execute();
 360 }
 361
 362 /**
 363  * An action which shows a form and does something based on the input from the form
 364  */
 365 abstract class FormAction extends Action {
 366
 367         /**
 368          * Get an HTMLForm descriptor array
 369          * @return Array
 370          */
 371         abstract protected function getFormFields();
 372
 373         /**
 374          * Add pre- or post-text to the form
 375          * @return String HTML which will be sent to $form->addPreText()
 376          */
 377         protected function preText() { return ''; }
 378
 379         /**
 380          * @return string
 381          */
 382         protected function postText() { return ''; }
 383
 384         /**
 385          * Play with the HTMLForm if you need to more substantially
 386          * @param $form HTMLForm
 387          */
 388         protected function alterForm( HTMLForm $form ) {}
 389
 390         /**
 391          * Get the HTMLForm to control behavior
 392          * @return HTMLForm|null
 393          */
 394         protected function getForm() {
 395                 $this->fields = $this->getFormFields();
 396
 397                 // Give hooks a chance to alter the form, adding extra fields or text etc
 398                 wfRunHooks( 'ActionModifyFormFields', array( $this->getName(), &$this->fields, $this->page ) );
 399
 400                 $form = new HTMLForm( $this->fields, $this->getContext(), $this->getName() );
 401                 $form->setSubmitCallback( array( $this, 'onSubmit' ) );
 402
 403                 // Retain query parameters (uselang etc)
 404                 $form->addHiddenField( 'action', $this->getName() ); // Might not be the same as the query string
 405                 $params = array_diff_key(
 406                         $this->getRequest()->getQueryValues(),
 407                         array( 'action' => null, 'title' => null )
 408                 );
 409                 $form->addHiddenField( 'redirectparams', wfArrayToCgi( $params ) );
 410
 411                 $form->addPreText( $this->preText() );
 412                 $form->addPostText( $this->postText() );
 413                 $this->alterForm( $form );
 414
 415                 // Give hooks a chance to alter the form, adding extra fields or text etc
 416                 wfRunHooks( 'ActionBeforeFormDisplay', array( $this->getName(), &$form, $this->page ) );
 417
 418                 return $form;
 419         }
 420
 421         /**
 422          * Process the form on POST submission.  If you return false from getFormFields(),
 423          * this will obviously never be reached.  If you don't want to do anything with the
 424          * form, just return false here
 425          * @param  $data Array
 426          * @return Bool|Array true for success, false for didn't-try, array of errors on failure
 427          */
 428         abstract public function onSubmit( $data );
 429
 430         /**
 431          * Do something exciting on successful processing of the form.  This might be to show
 432          * a confirmation message (watch, rollback, etc) or to redirect somewhere else (edit,
 433          * protect, etc).
 434          */
 435         abstract public function onSuccess();
 436
 437         /**
 438          * The basic pattern for actions is to display some sort of HTMLForm UI, maybe with
 439          * some stuff underneath (history etc); to do some processing on submission of that
 440          * form (delete, protect, etc) and to do something exciting on 'success', be that
 441          * display something new or redirect to somewhere.  Some actions have more exotic
 442          * behavior, but that's what subclassing is for :D
 443          */
 444         public function show() {
 445                 $this->setHeaders();
 446
 447                 // This will throw exceptions if there's a problem
 448                 $this->checkCanExecute( $this->getUser() );
 449
 450                 $form = $this->getForm();
 451                 if ( $form->show() ) {
 452                         $this->onSuccess();
 453                 }
 454         }
 455
 456         /**
 457          * @see Action::execute()
 458          *
 459          * @param $data array|null
 460          * @param $captureErrors bool
 461          * @throws ErrorPageError|Exception
 462          * @return bool
 463          */
 464         public function execute( array $data = null, $captureErrors = true ) {
 465                 try {
 466                         // Set a new context so output doesn't leak.
 467                         $this->context = clone $this->page->getContext();
 468
 469                         // This will throw exceptions if there's a problem
 470                         $this->checkCanExecute( $this->getUser() );
 471
 472                         $fields = array();
 473                         foreach ( $this->fields as $key => $params ) {
 474                                 if ( isset( $data[$key] ) ) {
 475                                         $fields[$key] = $data[$key];
 476                                 } elseif ( isset( $params['default'] ) ) {
 477                                         $fields[$key] = $params['default'];
 478                                 } else {
 479                                         $fields[$key] = null;
 480                                 }
 481                         }
 482                         $status = $this->onSubmit( $fields );
 483                         if ( $status === true ) {
 484                                 // This might do permanent stuff
 485                                 $this->onSuccess();
 486                                 return true;
 487                         } else {
 488                                 return false;
 489                         }
 490                 }
 491                 catch ( ErrorPageError $e ) {
 492                         if ( $captureErrors ) {
 493                                 return false;
 494                         } else {
 495                                 throw $e;
 496                         }
 497                 }
 498         }
 499 }
 500
 501 /**
 502  * An action which just does something, without showing a form first.
 503  */
 504 abstract class FormlessAction extends Action {
 505
 506         /**
 507          * Show something on GET request.
 508          * @return String|null will be added to the HTMLForm if present, or just added to the
 509          *     output if not.  Return null to not add anything
 510          */
 511         abstract public function onView();
 512
 513         /**
 514          * We don't want an HTMLForm
 515          * @return bool
 516          */
 517         protected function getFormFields() {
 518                 return false;
 519         }
 520
 521         /**
 522          * @param $data Array
 523          * @return bool
 524          */
 525         public function onSubmit( $data ) {
 526                 return false;
 527         }
 528
 529         /**
 530          * @return bool
 531          */
 532         public function onSuccess() {
 533                 return false;
 534         }
 535
 536         public function show() {
 537                 $this->setHeaders();
 538
 539                 // This will throw exceptions if there's a problem
 540                 $this->checkCanExecute( $this->getUser() );
 541
 542                 $this->getOutput()->addHTML( $this->onView() );
 543         }
 544
 545         /**
 546          * Execute the action silently, not giving any output.  Since these actions don't have
 547          * forms, they probably won't have any data, but some (eg rollback) may do
 548          * @param array $data values that would normally be in the GET request
 549          * @param bool $captureErrors whether to catch exceptions and just return false
 550          * @throws ErrorPageError|Exception
 551          * @return Bool whether execution was successful
 552          */
 553         public function execute( array $data = null, $captureErrors = true ) {
 554                 try {
 555                         // Set a new context so output doesn't leak.
 556                         $this->context = clone $this->page->getContext();
 557                         if ( is_array( $data ) ) {
 558                                 $this->context->setRequest( new FauxRequest( $data, false ) );
 559                         }
 560
 561                         // This will throw exceptions if there's a problem
 562                         $this->checkCanExecute( $this->getUser() );
 563
 564                         $this->onView();
 565                         return true;
 566                 }
 567                 catch ( ErrorPageError $e ) {
 568                         if ( $captureErrors ) {
 569                                 return false;
 570                         } else {
 571                                 throw $e;
 572                         }
 573                 }
 574         }
 575 }