includes/actions/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          * @since 1.17
  42          * @var WikiPage|Article|ImagePage|CategoryPage|Page $page
  43          */
  44         protected $page;
  45
  46         /**
  47          * IContextSource if specified; otherwise we'll use the Context from the Page
  48          * @since 1.17
  49          * @var IContextSource $context
  50          */
  51         protected $context;
  52
  53         /**
  54          * The fields used to create the HTMLForm
  55          * @since 1.17
  56          * @var array $fields
  57          */
  58         protected $fields;
  59
  60         /**
  61          * Get the Action subclass which should be used to handle this action, false if
  62          * the action is disabled, or null if it's not recognised
  63          * @param string $action
  64          * @param array $overrides
  65          * @return bool|null|string|callable
  66          */
  67         final private static function getClass( $action, array $overrides ) {
  68                 global $wgActions;
  69                 $action = strtolower( $action );
  70
  71                 if ( !isset( $wgActions[$action] ) ) {
  72                         return null;
  73                 }
  74
  75                 if ( $wgActions[$action] === false ) {
  76                         return false;
  77                 } elseif ( $wgActions[$action] === true && isset( $overrides[$action] ) ) {
  78                         return $overrides[$action];
  79                 } elseif ( $wgActions[$action] === true ) {
  80                         return ucfirst( $action ) . 'Action';
  81                 } else {
  82                         return $wgActions[$action];
  83                 }
  84         }
  85
  86         /**
  87          * Get an appropriate Action subclass for the given action
  88          * @since 1.17
  89          * @param string $action
  90          * @param Page $page
  91          * @param IContextSource $context
  92          * @return Action|bool|null False if the action is disabled, null
  93          *     if it is not recognised
  94          */
  95         final public static function factory( $action, Page $page, IContextSource $context = null ) {
  96                 $classOrCallable = self::getClass( $action, $page->getActionOverrides() );
  97
  98                 if ( is_string( $classOrCallable ) ) {
  99                         $obj = new $classOrCallable( $page, $context );
 100                         return $obj;
 101                 }
 102
 103                 if ( is_callable( $classOrCallable ) ) {
 104                         return call_user_func_array( $classOrCallable, array( $page, $context ) );
 105                 }
 106
 107                 return $classOrCallable;
 108         }
 109
 110         /**
 111          * Get the action that will be executed, not necessarily the one passed
 112          * passed through the "action" request parameter. Actions disabled in
 113          * $wgActions will be replaced by "nosuchaction".
 114          *
 115          * @since 1.19
 116          * @param IContextSource $context
 117          * @return string Action name
 118          */
 119         final public static function getActionName( IContextSource $context ) {
 120                 global $wgActions;
 121
 122                 $request = $context->getRequest();
 123                 $actionName = $request->getVal( 'action', 'view' );
 124
 125                 // Check for disabled actions
 126                 if ( isset( $wgActions[$actionName] ) && $wgActions[$actionName] === false ) {
 127                         $actionName = 'nosuchaction';
 128                 }
 129
 130                 // Workaround for bug #20966: inability of IE to provide an action dependent
 131                 // on which submit button is clicked.
 132                 if ( $actionName === 'historysubmit' ) {
 133                         if ( $request->getBool( 'revisiondelete' ) ) {
 134                                 $actionName = 'revisiondelete';
 135                         } elseif ( $request->getBool( 'editchangetags' ) ) {
 136                                 $actionName = 'editchangetags';
 137                         } else {
 138                                 $actionName = 'view';
 139                         }
 140                 } elseif ( $actionName == 'editredlink' ) {
 141                         $actionName = 'edit';
 142                 }
 143
 144                 // Trying to get a WikiPage for NS_SPECIAL etc. will result
 145                 // in WikiPage::factory throwing "Invalid or virtual namespace -1 given."
 146                 // For SpecialPages et al, default to action=view.
 147                 if ( !$context->canUseWikiPage() ) {
 148                         return 'view';
 149                 }
 150
 151                 $action = Action::factory( $actionName, $context->getWikiPage(), $context );
 152                 if ( $action instanceof Action ) {
 153                         return $action->getName();
 154                 }
 155
 156                 return 'nosuchaction';
 157         }
 158
 159         /**
 160          * Check if a given action is recognised, even if it's disabled
 161          * @since 1.17
 162          *
 163          * @param string $name Name of an action
 164          * @return bool
 165          */
 166         final public static function exists( $name ) {
 167                 return self::getClass( $name, array() ) !== null;
 168         }
 169
 170         /**
 171          * Get the IContextSource in use here
 172          * @since 1.17
 173          * @return IContextSource
 174          */
 175         final public function getContext() {
 176                 if ( $this->context instanceof IContextSource ) {
 177                         return $this->context;
 178                 } elseif ( $this->page instanceof Article ) {
 179                         // NOTE: $this->page can be a WikiPage, which does not have a context.
 180                         wfDebug( __METHOD__ . ": no context known, falling back to Article's context.\n" );
 181                         return $this->page->getContext();
 182                 }
 183
 184                 wfWarn( __METHOD__ . ': no context known, falling back to RequestContext::getMain().' );
 185                 return RequestContext::getMain();
 186         }
 187
 188         /**
 189          * Get the WebRequest being used for this instance
 190          * @since 1.17
 191          *
 192          * @return WebRequest
 193          */
 194         final public function getRequest() {
 195                 return $this->getContext()->getRequest();
 196         }
 197
 198         /**
 199          * Get the OutputPage being used for this instance
 200          * @since 1.17
 201          *
 202          * @return OutputPage
 203          */
 204         final public function getOutput() {
 205                 return $this->getContext()->getOutput();
 206         }
 207
 208         /**
 209          * Shortcut to get the User being used for this instance
 210          * @since 1.17
 211          *
 212          * @return User
 213          */
 214         final public function getUser() {
 215                 return $this->getContext()->getUser();
 216         }
 217
 218         /**
 219          * Shortcut to get the Skin being used for this instance
 220          * @since 1.17
 221          *
 222          * @return Skin
 223          */
 224         final public function getSkin() {
 225                 return $this->getContext()->getSkin();
 226         }
 227
 228         /**
 229          * Shortcut to get the user Language being used for this instance
 230          *
 231          * @return Language
 232          */
 233         final public function getLanguage() {
 234                 return $this->getContext()->getLanguage();
 235         }
 236
 237         /**
 238          * Shortcut to get the Title object from the page
 239          * @since 1.17
 240          *
 241          * @return Title
 242          */
 243         final public function getTitle() {
 244                 return $this->page->getTitle();
 245         }
 246
 247         /**
 248          * Get a Message object with context set
 249          * Parameters are the same as wfMessage()
 250          *
 251          * @return Message
 252          */
 253         final public function msg() {
 254                 $params = func_get_args();
 255                 return call_user_func_array( array( $this->getContext(), 'msg' ), $params );
 256         }
 257
 258         /**
 259          * Constructor.
 260          *
 261          * Only public since 1.21
 262          *
 263          * @param Page $page
 264          * @param IContextSource $context
 265          */
 266         public function __construct( Page $page, IContextSource $context = null ) {
 267                 if ( $context === null ) {
 268                         wfWarn( __METHOD__ . ' called without providing a Context object.' );
 269                         // NOTE: We could try to initialize $context using $page->getContext(),
 270                         //      if $page is an Article. That however seems to not work seamlessly.
 271                 }
 272
 273                 $this->page = $page;
 274                 $this->context = $context;
 275         }
 276
 277         /**
 278          * Return the name of the action this object responds to
 279          * @since 1.17
 280          *
 281          * @return string Lowercase name
 282          */
 283         abstract public function getName();
 284
 285         /**
 286          * Get the permission required to perform this action.  Often, but not always,
 287          * the same as the action name
 288          * @since 1.17
 289          *
 290          * @return string|null
 291          */
 292         public function getRestriction() {
 293                 return null;
 294         }
 295
 296         /**
 297          * Checks if the given user (identified by an object) can perform this action.  Can be
 298          * overridden by sub-classes with more complicated permissions schemes.  Failures here
 299          * must throw subclasses of ErrorPageError
 300          * @since 1.17
 301          *
 302          * @param User $user The user to check, or null to use the context user
 303          * @throws UserBlockedError|ReadOnlyError|PermissionsError
 304          */
 305         protected function checkCanExecute( User $user ) {
 306                 $right = $this->getRestriction();
 307                 if ( $right !== null ) {
 308                         $errors = $this->getTitle()->getUserPermissionsErrors( $right, $user );
 309                         if ( count( $errors ) ) {
 310                                 throw new PermissionsError( $right, $errors );
 311                         }
 312                 }
 313
 314                 if ( $this->requiresUnblock() && $user->isBlocked() ) {
 315                         $block = $user->getBlock();
 316                         throw new UserBlockedError( $block );
 317                 }
 318
 319                 // This should be checked at the end so that the user won't think the
 320                 // error is only temporary when he also don't have the rights to execute
 321                 // this action
 322                 if ( $this->requiresWrite() && wfReadOnly() ) {
 323                         throw new ReadOnlyError();
 324                 }
 325         }
 326
 327         /**
 328          * Whether this action requires the wiki not to be locked
 329          * @since 1.17
 330          *
 331          * @return bool
 332          */
 333         public function requiresWrite() {
 334                 return true;
 335         }
 336
 337         /**
 338          * Whether this action can still be executed by a blocked user
 339          * @since 1.17
 340          *
 341          * @return bool
 342          */
 343         public function requiresUnblock() {
 344                 return true;
 345         }
 346
 347         /**
 348          * Set output headers for noindexing etc.  This function will not be called through
 349          * the execute() entry point, so only put UI-related stuff in here.
 350          * @since 1.17
 351          */
 352         protected function setHeaders() {
 353                 $out = $this->getOutput();
 354                 $out->setRobotPolicy( "noindex,nofollow" );
 355                 $out->setPageTitle( $this->getPageTitle() );
 356                 $out->setSubtitle( $this->getDescription() );
 357                 $out->setArticleRelated( true );
 358         }
 359
 360         /**
 361          * Returns the name that goes in the \<h1\> page title
 362          *
 363          * @return string
 364          */
 365         protected function getPageTitle() {
 366                 return $this->getTitle()->getPrefixedText();
 367         }
 368
 369         /**
 370          * Returns the description that goes below the \<h1\> tag
 371          * @since 1.17
 372          *
 373          * @return string
 374          */
 375         protected function getDescription() {
 376                 return $this->msg( strtolower( $this->getName() ) )->escaped();
 377         }
 378
 379         /**
 380          * Adds help link with an icon via page indicators.
 381          * Link target can be overridden by a local message containing a wikilink:
 382          * the message key is: lowercase action name + '-helppage'.
 383          * @param string $to Target MediaWiki.org page title or encoded URL.
 384          * @param bool $overrideBaseUrl Whether $url is a full URL, to avoid MW.o.
 385          * @since 1.25
 386          */
 387         public function addHelpLink( $to, $overrideBaseUrl = false ) {
 388                 global $wgContLang;
 389                 $msg = wfMessage( $wgContLang->lc(
 390                         Action::getActionName( $this->getContext() )
 391                         ) . '-helppage' );
 392
 393                 if ( !$msg->isDisabled() ) {
 394                         $helpUrl = Skin::makeUrl( $msg->plain() );
 395                         $this->getOutput()->addHelpLink( $helpUrl, true );
 396                 } else {
 397                         $this->getOutput()->addHelpLink( $to, $overrideBaseUrl );
 398                 }
 399         }
 400
 401         /**
 402          * The main action entry point.  Do all output for display and send it to the context
 403          * output.  Do not use globals $wgOut, $wgRequest, etc, in implementations; use
 404          * $this->getOutput(), etc.
 405          * @since 1.17
 406          *
 407          * @throws ErrorPageError
 408          */
 409         abstract public function show();
 410
 411         /**
 412          * Call wfTransactionalTimeLimit() if this request was POSTed
 413          * @since 1.26
 414          */
 415         protected function useTransactionalTimeLimit() {
 416                 if ( $this->getRequest()->wasPosted() ) {
 417                         wfTransactionalTimeLimit();
 418                 }
 419         }
 420 }