MediaWiki  master
Hooks.php
Go to the documentation of this file.
1 <?php
2 
34 class Hooks {
39  protected static $handlers = [];
40 
49  public static function register( $name, $callback ) {
50  self::$handlers[$name][] = $callback;
51  }
52 
63  public static function clear( $name ) {
64  if ( !defined( 'MW_PHPUNIT_TEST' ) && !defined( 'MW_PARSER_TEST' ) ) {
65  throw new MWException( 'Cannot reset hooks in operation.' );
66  }
67 
68  unset( self::$handlers[$name] );
69  }
70 
80  public static function isRegistered( $name ) {
81  global $wgHooks;
82  return !empty( $wgHooks[$name] ) || !empty( self::$handlers[$name] );
83  }
84 
94  public static function getHandlers( $name ) {
95  global $wgHooks;
96 
97  if ( !self::isRegistered( $name ) ) {
98  return [];
99  } elseif ( !isset( self::$handlers[$name] ) ) {
100  return $wgHooks[$name];
101  } elseif ( !isset( $wgHooks[$name] ) ) {
102  return self::$handlers[$name];
103  } else {
104  return array_merge( self::$handlers[$name], $wgHooks[$name] );
105  }
106  }
107 
116  private static function callHook( $event, $hook, array $args, $deprecatedVersion = null,
117  &$fname = null
118  ) {
119  // Turn non-array values into an array. (Can't use casting because of objects.)
120  if ( !is_array( $hook ) ) {
121  $hook = [ $hook ];
122  }
123 
124  if ( !array_filter( $hook ) ) {
125  // Either array is empty or it's an array filled with null/false/empty.
126  return null;
127  }
128 
129  if ( is_array( $hook[0] ) ) {
130  // First element is an array, meaning the developer intended
131  // the first element to be a callback. Merge it in so that
132  // processing can be uniform.
133  $hook = array_merge( $hook[0], array_slice( $hook, 1 ) );
134  }
135 
141  if ( $hook[0] instanceof Closure ) {
142  $fname = "hook-$event-closure";
143  $callback = array_shift( $hook );
144  } elseif ( is_object( $hook[0] ) ) {
145  $object = array_shift( $hook );
146  $method = array_shift( $hook );
147 
148  // If no method was specified, default to on$event.
149  if ( $method === null ) {
150  $method = "on$event";
151  }
152 
153  $fname = get_class( $object ) . '::' . $method;
154  $callback = [ $object, $method ];
155  } elseif ( is_string( $hook[0] ) ) {
156  $fname = $callback = array_shift( $hook );
157  } else {
158  throw new MWException( 'Unknown datatype in hooks for ' . $event . "\n" );
159  }
160 
161  // Run autoloader (workaround for call_user_func_array bug)
162  // and throw error if not callable.
163  if ( !is_callable( $callback ) ) {
164  throw new MWException( 'Invalid callback ' . $fname . ' in hooks for ' . $event . "\n" );
165  }
166 
167  // mark hook as deprecated, if deprecation version is specified
168  if ( $deprecatedVersion !== null ) {
169  wfDeprecated( "$event hook (used in $fname)", $deprecatedVersion );
170  }
171 
172  // Call the hook.
173  $hook_args = array_merge( $hook, $args );
174  return call_user_func_array( $callback, $hook_args );
175  }
176 
200  public static function run( $event, array $args = [], $deprecatedVersion = null ) {
201  foreach ( self::getHandlers( $event ) as $hook ) {
202  $retval = self::callHook( $event, $hook, $args, $deprecatedVersion );
203  if ( $retval === null ) {
204  continue;
205  }
206 
207  // Process the return value.
208  if ( is_string( $retval ) ) {
209  // String returned means error.
210  throw new FatalError( $retval );
211  } elseif ( $retval === false ) {
212  // False was returned. Stop processing, but no error.
213  return false;
214  }
215  }
216 
217  return true;
218  }
219 
231  public static function runWithoutAbort( $event, array $args = [], $deprecatedVersion = null ) {
232  foreach ( self::getHandlers( $event ) as $hook ) {
233  $fname = null;
234  $retval = self::callHook( $event, $hook, $args, $deprecatedVersion, $fname );
235  if ( $retval !== null && $retval !== true ) {
236  throw new UnexpectedValueException( "Invalid return from $fname for unabortable $event." );
237  }
238  }
239  return true;
240  }
241 }
The wiki should then use memcached to cache various data To use multiple just add more items to the array To increase the weight of a make its entry a array("192.168.0.1:11211", 2))
static getHandlers( $name)
Returns an array of all the event functions attached to a hook This combines functions registered via...
Definition: Hooks.php:94
static clear( $name)
Clears hooks registered via Hooks::register().
Definition: Hooks.php:63
if( $line===false) $args
Definition: cdb.php:64
static callHook( $event, $hook, array $args, $deprecatedVersion=null, &$fname=null)
Definition: Hooks.php:116
$wgHooks['ArticleShow'][]
Definition: hooks.txt:108
static runWithoutAbort( $event, array $args=[], $deprecatedVersion=null)
Call hook functions defined in Hooks::register and $wgHooks.
Definition: Hooks.php:231
This document is intended to provide useful advice for parties seeking to redistribute MediaWiki to end users It s targeted particularly at maintainers for Linux since it s been observed that distribution packages of MediaWiki often break We ve consistently had to recommend that users seeking support use official tarballs instead of their distribution s and this often solves whatever problem the user is having It would be nice if this could such as
Definition: distributors.txt:9
if(defined( 'MW_SETUP_CALLBACK')) $fname
Customization point after all loading (constants, functions, classes, DefaultSettings, LocalSettings).
Definition: Setup.php:121
Exception class which takes an HTML error message, and does not produce a backtrace.
Definition: FatalError.php:28
injection txt This is an overview of how MediaWiki makes use of dependency injection The design described here grew from the discussion of RFC T384 The term dependency this means that anything an object needs to operate should be injected from the the object itself should only know narrow no concrete implementation of the logic it relies on The requirement to inject everything typically results in an architecture that based on two main types of and essentially stateless service objects that use other service objects to operate on the value objects As of the beginning MediaWiki is only starting to use the DI approach Much of the code still relies on global state or direct resulting in a highly cyclical dependency which acts as the top level factory for services in MediaWiki which can be used to gain access to default instances of various services MediaWikiServices however also allows new services to be defined and default services to be redefined Services are defined or redefined by providing a callback the instantiator that will return a new instance of the service When it will create an instance of MediaWikiServices and populate it with the services defined in the files listed by thereby bootstrapping the DI framework Per $wgServiceWiringFiles lists includes ServiceWiring php
Definition: injection.txt:35
static isRegistered( $name)
Returns true if a hook has a function registered to it.
Definition: Hooks.php:80
wfDeprecated( $function, $version=false, $component=false, $callerOffset=2)
Throws a warning that $function is deprecated.
Allows to change the fields on the form that will be generated $name
Definition: hooks.txt:276
static $handlers
Array of events mapped to an array of callbacks to be run when that event is triggered.
Definition: Hooks.php:39
static run( $event, array $args=[], $deprecatedVersion=null)
Call hook functions defined in Hooks::register and $wgHooks.
Definition: Hooks.php:200