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