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-rw-r--r--includes/Hooks.php282
1 files changed, 106 insertions, 176 deletions
diff --git a/includes/Hooks.php b/includes/Hooks.php
index 8cc7acea..396e360d 100644
--- a/includes/Hooks.php
+++ b/includes/Hooks.php
@@ -1,4 +1,5 @@
<?php
+
/**
* A tool for running hook functions.
*
@@ -37,40 +38,43 @@ class MWHookException extends MWException {}
*/
class Hooks {
+ /**
+ * Array of events mapped to an array of callbacks to be run
+ * when that event is triggered.
+ */
protected static $handlers = array();
/**
- * Clears hooks registered via Hooks::register(). Does not touch $wgHooks.
- * This is intended for use while testing and will fail if MW_PHPUNIT_TEST is not defined.
+ * Attach an event handler to a given hook.
*
- * @since 1.21
- *
- * @param string $name the name of the hook to clear.
+ * @param string $name Name of hook
+ * @param mixed $callback Callback function to attach
*
- * @throws MWException if not in testing mode.
+ * @since 1.18
*/
- public static function clear( $name ) {
- if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
- throw new MWException( 'can not reset hooks in operation.' );
+ public static function register( $name, $callback ) {
+ if ( !isset( self::$handlers[$name] ) ) {
+ self::$handlers[$name] = array();
}
- unset( self::$handlers[$name] );
+ self::$handlers[$name][] = $callback;
}
/**
- * Attach an event handler to a given hook
+ * Clears hooks registered via Hooks::register(). Does not touch $wgHooks.
+ * This is intended for use while testing and will fail if MW_PHPUNIT_TEST is not defined.
*
- * @since 1.18
+ * @param string $name the name of the hook to clear.
*
- * @param string $name name of hook
- * @param $callback Mixed: callback function to attach
+ * @since 1.21
+ * @throws MWException if not in testing mode.
*/
- public static function register( $name, $callback ) {
- if( !isset( self::$handlers[$name] ) ) {
- self::$handlers[$name] = array();
+ public static function clear( $name ) {
+ if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
+ throw new MWException( 'Cannot reset hooks in operation.' );
}
- self::$handlers[$name][] = $callback;
+ unset( self::$handlers[$name] );
}
/**
@@ -79,216 +83,139 @@ class Hooks {
*
* @since 1.18
*
- * @param string $name name of hook
- * @return Boolean: true if the hook has a function registered to it
+ * @param string $name Name of hook
+ * @return bool True if the hook has a function registered to it
*/
public static function isRegistered( $name ) {
global $wgHooks;
-
return !empty( $wgHooks[$name] ) || !empty( self::$handlers[$name] );
}
/**
* Returns an array of all the event functions attached to a hook
* This combines functions registered via Hooks::register and with $wgHooks.
- * @since 1.18
*
- * @throws MWException
- * @throws FatalError
- * @param string $name name of the hook
+ * @since 1.18
*
+ * @param string $name Name of the hook
* @return array
*/
public static function getHandlers( $name ) {
global $wgHooks;
- // Return quickly in the most common case
- if ( empty( self::$handlers[$name] ) && empty( $wgHooks[$name] ) ) {
+ if ( !self::isRegistered( $name ) ) {
return array();
- }
-
- if ( !is_array( self::$handlers ) ) {
- throw new MWException( "Local hooks array is not an array!\n" );
- }
-
- if ( !is_array( $wgHooks ) ) {
- throw new MWException( "Global hooks array is not an array!\n" );
- }
-
- if ( empty( Hooks::$handlers[$name] ) ) {
- $hooks = $wgHooks[$name];
- } elseif ( empty( $wgHooks[$name] ) ) {
- $hooks = Hooks::$handlers[$name];
+ } elseif ( !isset( self::$handlers[$name] ) ) {
+ return $wgHooks[$name];
+ } elseif ( !isset( $wgHooks[$name] ) ) {
+ return self::$handlers[$name];
} else {
- // so they are both not empty...
- $hooks = array_merge( Hooks::$handlers[$name], $wgHooks[$name] );
+ return array_merge( self::$handlers[$name], $wgHooks[$name] );
}
-
- if ( !is_array( $hooks ) ) {
- throw new MWException( "Hooks array for event '$name' is not an array!\n" );
- }
-
- return $hooks;
}
/**
- * Call hook functions defined in Hooks::register
+ * Call hook functions defined in Hooks::register and $wgHooks.
*
- * @param string $event event name
- * @param $args Array: parameters passed to hook functions
+ * For a certain hook event, fetch the array of hook events and
+ * process them. Determine the proper callback for each hook and
+ * then call the actual hook using the appropriate arguments.
+ * Finally, process the return value and return/throw accordingly.
*
+ * @param string $event Event name
+ * @param array $args Array of parameters passed to hook functions
+ * @return bool True if no handler aborted the hook
+ *
+ * @since 1.22 A hook function is not required to return a value for
+ * processing to continue. Not returning a value (or explicitly
+ * returning null) is equivalent to returning true.
* @throws MWException
* @throws FatalError
- * @return Boolean True if no handler aborted the hook
*/
- public static function run( $event, $args = array() ) {
- global $wgHooks;
-
- // Return quickly in the most common case
- if ( empty( self::$handlers[$event] ) && empty( $wgHooks[$event] ) ) {
- return true;
- }
-
+ public static function run( $event, array $args = array() ) {
wfProfileIn( 'hook: ' . $event );
- $hooks = self::getHandlers( $event );
+ foreach ( self::getHandlers( $event ) as $hook ) {
+ // Turn non-array values into an array. (Can't use casting because of objects.)
+ if ( !is_array( $hook ) ) {
+ $hook = array( $hook );
+ }
- foreach ( $hooks as $hook ) {
- $object = null;
- $method = null;
- $func = null;
- $data = null;
- $have_data = false;
- $closure = false;
- $badhookmsg = false;
+ if ( !array_filter( $hook ) ) {
+ // Either array is empty or it's an array filled with null/false/empty.
+ continue;
+ } elseif ( is_array( $hook[0] ) ) {
+ // First element is an array, meaning the developer intended
+ // the first element to be a callback. Merge it in so that
+ // processing can be uniform.
+ $hook = array_merge( $hook[0], array_slice( $hook, 1 ) );
+ }
/**
* $hook can be: a function, an object, an array of $function and
* $data, an array of just a function, an array of object and
* method, or an array of object, method, and data.
*/
- if ( is_array( $hook ) ) {
- if ( count( $hook ) < 1 ) {
- throw new MWException( 'Empty array in hooks for ' . $event . "\n" );
- } elseif ( is_object( $hook[0] ) ) {
- $object = $hook[0];
- if ( $object instanceof Closure ) {
- $closure = true;
- if ( count( $hook ) > 1 ) {
- $data = $hook[1];
- $have_data = true;
- }
- } else {
- if ( count( $hook ) < 2 ) {
- $method = 'on' . $event;
- } else {
- $method = $hook[1];
- if ( count( $hook ) > 2 ) {
- $data = $hook[2];
- $have_data = true;
- }
- }
- }
- } elseif ( is_string( $hook[0] ) ) {
- $func = $hook[0];
- if ( count( $hook ) > 1) {
- $data = $hook[1];
- $have_data = true;
- }
- } else {
- throw new MWException( 'Unknown datatype in hooks for ' . $event . "\n" );
- }
- } elseif ( is_string( $hook ) ) { # functions look like strings, too
- $func = $hook;
- } elseif ( is_object( $hook ) ) {
- $object = $hook;
- if ( $object instanceof Closure ) {
- $closure = true;
- } else {
- $method = "on" . $event;
+ if ( $hook[0] instanceof Closure ) {
+ $func = "hook-$event-closure";
+ $callback = array_shift( $hook );
+ } elseif ( is_object( $hook[0] ) ) {
+ $object = array_shift( $hook );
+ $method = array_shift( $hook );
+
+ // If no method was specified, default to on$event.
+ if ( $method === null ) {
+ $method = "on$event";
}
- } else {
- throw new MWException( 'Unknown datatype in hooks for ' . $event . "\n" );
- }
-
- /* We put the first data element on, if needed. */
- if ( $have_data ) {
- $hook_args = array_merge( array( $data ), $args );
- } else {
- $hook_args = $args;
- }
- if ( $closure ) {
- $callback = $object;
- $func = "hook-$event-closure";
- } elseif ( isset( $object ) ) {
$func = get_class( $object ) . '::' . $method;
$callback = array( $object, $method );
+ } elseif ( is_string( $hook[0] ) ) {
+ $func = $callback = array_shift( $hook );
} else {
- $callback = $func;
+ throw new MWException( 'Unknown datatype in hooks for ' . $event . "\n" );
}
// Run autoloader (workaround for call_user_func_array bug)
- is_callable( $callback );
+ // and throw error if not callable.
+ if ( !is_callable( $callback ) ) {
+ throw new MWException( 'Invalid callback in hooks for ' . $event . "\n" );
+ }
- /**
- * Call the hook. The documentation of call_user_func_array clearly
- * states that FALSE is returned on failure. However this is not
- * case always. In some version of PHP if the function signature
- * does not match the call signature, PHP will issue an warning:
- * Param y in x expected to be a reference, value given.
- *
- * In that case the call will also return null. The following code
- * catches that warning and provides better error message. The
- * function documentation also says that:
- * In other words, it does not depend on the function signature
- * whether the parameter is passed by a value or by a reference.
- * There is also PHP bug http://bugs.php.net/bug.php?id=47554 which
- * is unsurprisingly marked as bogus. In short handling of failures
- * with call_user_func_array is a failure, the documentation for that
- * function is wrong and misleading and PHP developers don't see any
- * problem here.
+ /*
+ * Call the hook. The documentation of call_user_func_array says
+ * false is returned on failure. However, if the function signature
+ * does not match the call signature, PHP will issue an warning and
+ * return null instead. The following code catches that warning and
+ * provides better error message.
*/
$retval = null;
- set_error_handler( 'Hooks::hookErrorHandler' );
+ $badhookmsg = null;
+ $hook_args = array_merge( $hook, $args );
+
+ // Profile first in case the Profiler causes errors.
wfProfileIn( $func );
+ set_error_handler( 'Hooks::hookErrorHandler' );
try {
$retval = call_user_func_array( $callback, $hook_args );
} catch ( MWHookException $e ) {
$badhookmsg = $e->getMessage();
}
- wfProfileOut( $func );
restore_error_handler();
+ wfProfileOut( $func );
- /* String return is an error; false return means stop processing. */
+ // Process the return value.
if ( is_string( $retval ) ) {
+ // String returned means error.
throw new FatalError( $retval );
- } elseif( $retval === null ) {
- if ( $closure ) {
- $prettyFunc = "$event closure";
- } elseif( is_array( $callback ) ) {
- if( is_object( $callback[0] ) ) {
- $prettyClass = get_class( $callback[0] );
- } else {
- $prettyClass = strval( $callback[0] );
- }
- $prettyFunc = $prettyClass . '::' . strval( $callback[1] );
- } else {
- $prettyFunc = strval( $callback );
- }
- if ( $badhookmsg ) {
- throw new MWException(
- 'Detected bug in an extension! ' .
- "Hook $prettyFunc has invalid call signature; " . $badhookmsg
- );
- } else {
- throw new MWException(
- 'Detected bug in an extension! ' .
- "Hook $prettyFunc failed to return a value; " .
- 'should return true to continue hook processing or false to abort.'
- );
- }
- } elseif ( !$retval ) {
+ } elseif ( $badhookmsg !== null ) {
+ // Exception was thrown from Hooks::hookErrorHandler.
+ throw new MWException(
+ 'Detected bug in an extension! ' .
+ "Hook $func has invalid call signature; " . $badhookmsg
+ );
+ } elseif ( $retval === false ) {
wfProfileOut( 'hook: ' . $event );
+ // False was returned. Stop processing, but no error.
return false;
}
}
@@ -298,18 +225,21 @@ class Hooks {
}
/**
+ * Handle PHP errors issued inside a hook. Catch errors that have to do with
+ * a function expecting a reference, and let all others pass through.
+ *
* This REALLY should be protected... but it's public for compatibility
*
* @since 1.18
*
- * @param int $errno Unused
- * @param string $errstr error message
- * @throws MWHookException
- * @return Boolean: false
+ * @param int $errno Error number (unused)
+ * @param string $errstr Error message
+ * @throws MWHookException If the error has to do with the function signature
+ * @return bool Always returns false
*/
public static function hookErrorHandler( $errno, $errstr ) {
if ( strpos( $errstr, 'expected to be a reference, value given' ) !== false ) {
- throw new MWHookException( $errstr );
+ throw new MWHookException( $errstr, $errno );
}
return false;
}