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Hooks.php
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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 }
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
static runWithoutAbort( $event, array $args=[], $deprecatedVersion=null)
Call hook functions defined in Hooks::register and $wgHooks.
Definition: Hooks.php:231
$wgHooks
Global list of hooks.
Abort the web request with a custom HTML string that will represent the entire response.
Definition: FatalError.php: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.
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