<?php
/**
- * Hooks.php -- a tool for running hook functions
+ * A tool for running hook functions.
+ *
* Copyright 2004, 2005 Evan Prodromou <evan@wikitravel.org>.
*
* This program is free software; you can redistribute it and/or modify
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*
* @author Evan Prodromou <evan@wikitravel.org>
- * @package MediaWiki
* @see hooks.txt
+ * @file
*/
-if (defined('MEDIAWIKI')) {
-
- /**
- * Because programmers assign to $wgHooks, we need to be very
- * careful about its contents. So, there's a lot more error-checking
- * in here than would normally be necessary.
- */
-
- function wfRunHooks($event, $args = null) {
-
- global $wgHooks;
- $fname = 'wfRunHooks';
- wfProfileIn( $fname );
-
- if (!is_array($wgHooks)) {
- wfDieDebugBacktrace("Global hooks array is not an array!\n");
- wfProfileOut( $fname );
- return false;
- }
- if (!array_key_exists($event, $wgHooks)) {
- wfProfileOut( $fname );
- return true;
- }
-
- if (!is_array($wgHooks[$event])) {
- wfDieDebugBacktrace("Hooks array for event '$event' is not an array!\n");
- wfProfileOut( $fname );
- return false;
- }
-
- foreach ($wgHooks[$event] as $hook) {
-
- $object = NULL;
- $method = NULL;
- $func = NULL;
- $data = NULL;
- $have_data = false;
-
- /* $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) {
- wfDieDebugBacktrace("Empty array in hooks for " . $event . "\n");
- } else if (is_object($hook[0])) {
- $object = $hook[0];
- if (count($hook) < 2) {
+/**
+ * Call hook functions defined in $wgHooks
+ *
+ * Because programmers assign to $wgHooks, we need to be very
+ * careful about its contents. So, there's a lot more error-checking
+ * in here than would normally be necessary.
+ *
+ * @param $event String: event name
+ * @param $args Array: parameters passed to hook functions
+ * @return Boolean
+ */
+function wfRunHooks($event, $args = array()) {
+
+ global $wgHooks;
+
+ // Return quickly in the most common case
+ if ( !isset( $wgHooks[$event] ) ) {
+ return true;
+ }
+
+ if (!is_array($wgHooks)) {
+ throw new MWException("Global hooks array is not an array!\n");
+ }
+
+ if (!is_array($wgHooks[$event])) {
+ throw new MWException("Hooks array for event '$event' is not an array!\n");
+ }
+
+ foreach ($wgHooks[$event] as $index => $hook) {
+
+ $object = null;
+ $method = null;
+ $func = null;
+ $data = null;
+ $have_data = false;
+ $closure = false;
+ $badhookmsg = false;
+
+ /* $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");
+ } else if ( is_object( $hook[0] ) ) {
+ $object = $wgHooks[$event][$index][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) {
+ if ( count( $hook ) > 2 ) {
$data = $hook[2];
$have_data = true;
}
}
- } else if (is_string($hook[0])) {
- $func = $hook[0];
- if (count($hook) > 1) {
- $data = $hook[1];
- $have_data = true;
- }
- } else {
- wfDieDebugBacktrace("Unknown datatype in hooks for " . $event . "\n");
}
- } else if (is_string($hook)) { # functions look like strings, too
- $func = $hook;
- } else if (is_object($hook)) {
- $object = $hook;
- $method = "on" . $event;
+ } else if ( is_string( $hook[0] ) ) {
+ $func = $hook[0];
+ if ( count( $hook ) > 1) {
+ $data = $hook[1];
+ $have_data = true;
+ }
} else {
- wfDieDebugBacktrace("Unknown datatype in hooks for " . $event . "\n");
+ 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 if ( is_string( $hook ) ) { # functions look like strings, too
+ $func = $hook;
+ } else if ( is_object( $hook ) ) {
+ $object = $wgHooks[$event][$index];
+ if ( $object instanceof Closure ) {
+ $closure = true;
} else {
- $hook_args = $args;
- }
-
-
- if ( $object ) {
- $func = get_class( $object ) . '::' . $method;
+ $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 ( false !== ( $pos = strpos( $func, '::' ) ) ) {
+ $callback = array( substr( $func, 0, $pos ), substr( $func, $pos + 2 ) );
+ } else {
+ $callback = $func;
+ }
- /* Call the hook. */
- wfProfileIn( $func );
- if ($object) {
- $retval = call_user_func_array(array($object, $method), $hook_args);
+ // Run autoloader (workaround for call_user_func_array bug)
+ is_callable( $callback );
+
+ /* 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.
+ */
+ $retval = null;
+ set_error_handler( 'hookErrorHandler' );
+ wfProfileIn( $func );
+ try {
+ $retval = call_user_func_array( $callback, $hook_args );
+ } catch ( MWHookException $e ) {
+ $badhookmsg = $e->getMessage();
+ }
+ wfProfileOut( $func );
+ restore_error_handler();
+
+ /* String return is an error; false return means stop processing. */
+ if ( is_string( $retval ) ) {
+ global $wgOut;
+ $wgOut->showFatalError( $retval );
+ return false;
+ } 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 {
- $retval = call_user_func_array($func, $hook_args);
+ $prettyFunc = strval( $callback );
}
- wfProfileOut( $func );
-
- /* String return is an error; false return means stop processing. */
-
- if (is_string($retval)) {
- global $wgOut;
- $wgOut->fatalError($retval);
- wfProfileOut( $fname );
- return false;
- } else if (!$retval) {
- wfProfileOut( $fname );
- return false;
+ 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 $prettyFunc failed to return a value; " .
+ "should return true to continue hook processing or false to abort." );
}
+ } else if ( !$retval ) {
+ return false;
}
-
- wfProfileOut( $fname );
- return true;
}
-} /* if defined(MEDIAWIKI) */
-?>
+
+ return true;
+}
+
+function hookErrorHandler( $errno, $errstr ) {
+ if ( strpos( $errstr, 'expected to be a reference, value given' ) !== false ) {
+ throw new MWHookException( $errstr );
+ }
+ return false;
+}
+
+class MWHookException extends MWException {}
\ No newline at end of file