3 * The plugin API is located in this file, which allows for creating actions
4 * and filters and hooking functions, and methods. The functions or methods will
5 * then be run when the action or filter is called.
7 * The API callback examples reference functions, but can be methods of classes.
8 * To hook methods, you'll need to pass an array one of two ways.
10 * Any of the syntaxes explained in the PHP documentation for the
11 * {@link http://us2.php.net/manual/en/language.pseudo-types.php#language.types.callback 'callback'}
14 * Also see the {@link http://codex.wordpress.org/Plugin_API Plugin API} for
15 * more information and examples on how to use a lot of these functions.
22 // Initialize the filter globals.
23 global $wp_filter, $wp_actions, $merged_filters, $wp_current_filter;
25 if ( ! isset( $wp_filter ) )
28 if ( ! isset( $wp_actions ) )
29 $wp_actions = array();
31 if ( ! isset( $merged_filters ) )
32 $merged_filters = array();
34 if ( ! isset( $wp_current_filter ) )
35 $wp_current_filter = array();
38 * Hook a function or method to a specific filter action.
40 * WordPress offers filter hooks to allow plugins to modify
41 * various types of internal data at runtime.
43 * A plugin can modify data by binding a callback to a filter hook. When the filter
44 * is later applied, each bound callback is run in order of priority, and given
45 * the opportunity to modify a value by returning a new value.
47 * The following example shows how a callback function is bound to a filter hook.
48 * Note that $example is passed to the callback, (maybe) modified, then returned:
51 * function example_callback( $example ) {
52 * // Maybe modify $example in some way
55 * add_filter( 'example_filter', 'example_callback' );
58 * Since WordPress 1.5.1, bound callbacks can take as many arguments as are
59 * passed as parameters in the corresponding apply_filters() call. The $accepted_args
60 * parameter allows for calling functions only when the number of args match.
62 * <strong>Note:</strong> the function will return true whether or not the callback
63 * is valid. It is up to you to take care. This is done for optimization purposes,
64 * so everything is as quick as possible.
68 * @global array $wp_filter A multidimensional array of all hooks and the callbacks hooked to them.
69 * @global array $merged_filters Tracks the tags that need to be merged for later. If the hook is added,
70 * it doesn't need to run through that process.
72 * @param string $tag The name of the filter to hook the $function_to_add callback to.
73 * @param callback $function_to_add The callback to be run when the filter is applied.
74 * @param int $priority Optional. Used to specify the order in which the functions
75 * associated with a particular action are executed. Default 10.
76 * Lower numbers correspond with earlier execution,
77 * and functions with the same priority are executed
78 * in the order in which they were added to the action.
79 * @param int $accepted_args Optional. The number of arguments the function accepts. Default 1.
80 * @return boolean true
82 function add_filter( $tag, $function_to_add, $priority = 10, $accepted_args = 1 ) {
83 global $wp_filter, $merged_filters;
85 $idx = _wp_filter_build_unique_id($tag, $function_to_add, $priority);
86 $wp_filter[$tag][$priority][$idx] = array('function' => $function_to_add, 'accepted_args' => $accepted_args);
87 unset( $merged_filters[ $tag ] );
92 * Check if any filter has been registered for a hook.
96 * @global array $wp_filter Stores all of the filters.
98 * @param string $tag The name of the filter hook.
99 * @param callback|bool $function_to_check Optional. The callback to check for. Default false.
100 * @return bool|int If $function_to_check is omitted, returns boolean for whether the hook has
101 * anything registered. When checking a specific function, the priority of that
102 * hook is returned, or false if the function is not attached. When using the
103 * $function_to_check argument, this function may return a non-boolean value
104 * that evaluates to false (e.g.) 0, so use the === operator for testing the
107 function has_filter($tag, $function_to_check = false) {
108 // Don't reset the internal array pointer
109 $wp_filter = $GLOBALS['wp_filter'];
111 $has = ! empty( $wp_filter[ $tag ] );
113 // Make sure at least one priority has a filter callback
116 foreach ( $wp_filter[ $tag ] as $callbacks ) {
117 if ( ! empty( $callbacks ) ) {
128 if ( false === $function_to_check || false == $has )
131 if ( !$idx = _wp_filter_build_unique_id($tag, $function_to_check, false) )
134 foreach ( (array) array_keys($wp_filter[$tag]) as $priority ) {
135 if ( isset($wp_filter[$tag][$priority][$idx]) )
143 * Call the functions added to a filter hook.
145 * The callback functions attached to filter hook $tag are invoked by calling
146 * this function. This function can be used to create a new filter hook by
147 * simply calling this function with the name of the new hook specified using
148 * the $tag parameter.
150 * The function allows for additional arguments to be added and passed to hooks.
152 * // Our filter callback function
153 * function example_callback( $string, $arg1, $arg2 ) {
154 * // (maybe) modify $string
157 * add_filter( 'example_filter', 'example_callback', 10, 3 );
159 * // Apply the filters by calling the 'example_callback' function we
160 * // "hooked" to 'example_filter' using the add_filter() function above.
161 * // - 'example_filter' is the filter hook $tag
162 * // - 'filter me' is the value being filtered
163 * // - $arg1 and $arg2 are the additional arguments passed to the callback.
164 * $value = apply_filters( 'example_filter', 'filter me', $arg1, $arg2 );
169 * @global array $wp_filter Stores all of the filters.
170 * @global array $merged_filters Merges the filter hooks using this function.
171 * @global array $wp_current_filter Stores the list of current filters with the current one last.
173 * @param string $tag The name of the filter hook.
174 * @param mixed $value The value on which the filters hooked to <tt>$tag</tt> are applied on.
175 * @param mixed $var Additional variables passed to the functions hooked to <tt>$tag</tt>.
176 * @return mixed The filtered value after all hooked functions are applied to it.
178 function apply_filters( $tag, $value ) {
179 global $wp_filter, $merged_filters, $wp_current_filter;
183 // Do 'all' actions first.
184 if ( isset($wp_filter['all']) ) {
185 $wp_current_filter[] = $tag;
186 $args = func_get_args();
187 _wp_call_all_hook($args);
190 if ( !isset($wp_filter[$tag]) ) {
191 if ( isset($wp_filter['all']) )
192 array_pop($wp_current_filter);
196 if ( !isset($wp_filter['all']) )
197 $wp_current_filter[] = $tag;
200 if ( !isset( $merged_filters[ $tag ] ) ) {
201 ksort($wp_filter[$tag]);
202 $merged_filters[ $tag ] = true;
205 reset( $wp_filter[ $tag ] );
208 $args = func_get_args();
211 foreach( (array) current($wp_filter[$tag]) as $the_ )
212 if ( !is_null($the_['function']) ){
214 $value = call_user_func_array($the_['function'], array_slice($args, 1, (int) $the_['accepted_args']));
217 } while ( next($wp_filter[$tag]) !== false );
219 array_pop( $wp_current_filter );
225 * Execute functions hooked on a specific filter hook, specifying arguments in an array.
227 * @see apply_filters() This function is identical, but the arguments passed to the
228 * functions hooked to <tt>$tag</tt> are supplied using an array.
232 * @global array $wp_filter Stores all of the filters
233 * @global array $merged_filters Merges the filter hooks using this function.
234 * @global array $wp_current_filter Stores the list of current filters with the current one last
236 * @param string $tag The name of the filter hook.
237 * @param array $args The arguments supplied to the functions hooked to $tag.
238 * @return mixed The filtered value after all hooked functions are applied to it.
240 function apply_filters_ref_array($tag, $args) {
241 global $wp_filter, $merged_filters, $wp_current_filter;
243 // Do 'all' actions first
244 if ( isset($wp_filter['all']) ) {
245 $wp_current_filter[] = $tag;
246 $all_args = func_get_args();
247 _wp_call_all_hook($all_args);
250 if ( !isset($wp_filter[$tag]) ) {
251 if ( isset($wp_filter['all']) )
252 array_pop($wp_current_filter);
256 if ( !isset($wp_filter['all']) )
257 $wp_current_filter[] = $tag;
260 if ( !isset( $merged_filters[ $tag ] ) ) {
261 ksort($wp_filter[$tag]);
262 $merged_filters[ $tag ] = true;
265 reset( $wp_filter[ $tag ] );
268 foreach( (array) current($wp_filter[$tag]) as $the_ )
269 if ( !is_null($the_['function']) )
270 $args[0] = call_user_func_array($the_['function'], array_slice($args, 0, (int) $the_['accepted_args']));
272 } while ( next($wp_filter[$tag]) !== false );
274 array_pop( $wp_current_filter );
280 * Removes a function from a specified filter hook.
282 * This function removes a function attached to a specified filter hook. This
283 * method can be used to remove default functions attached to a specific filter
284 * hook and possibly replace them with a substitute.
286 * To remove a hook, the $function_to_remove and $priority arguments must match
287 * when the hook was added. This goes for both filters and actions. No warning
288 * will be given on removal failure.
292 * @param string $tag The filter hook to which the function to be removed is hooked.
293 * @param callback $function_to_remove The name of the function which should be removed.
294 * @param int $priority Optional. The priority of the function. Default 10.
295 * @return boolean Whether the function existed before it was removed.
297 function remove_filter( $tag, $function_to_remove, $priority = 10 ) {
298 $function_to_remove = _wp_filter_build_unique_id( $tag, $function_to_remove, $priority );
300 $r = isset( $GLOBALS['wp_filter'][ $tag ][ $priority ][ $function_to_remove ] );
303 unset( $GLOBALS['wp_filter'][ $tag ][ $priority ][ $function_to_remove ] );
304 if ( empty( $GLOBALS['wp_filter'][ $tag ][ $priority ] ) ) {
305 unset( $GLOBALS['wp_filter'][ $tag ][ $priority ] );
307 if ( empty( $GLOBALS['wp_filter'][ $tag ] ) ) {
308 $GLOBALS['wp_filter'][ $tag ] = array();
310 unset( $GLOBALS['merged_filters'][ $tag ] );
317 * Remove all of the hooks from a filter.
321 * @param string $tag The filter to remove hooks from.
322 * @param int|bool $priority Optional. The priority number to remove. Default false.
323 * @return bool True when finished.
325 function remove_all_filters( $tag, $priority = false ) {
326 global $wp_filter, $merged_filters;
328 if ( isset( $wp_filter[ $tag ]) ) {
329 if ( false !== $priority && isset( $wp_filter[ $tag ][ $priority ] ) ) {
330 $wp_filter[ $tag ][ $priority ] = array();
332 $wp_filter[ $tag ] = array();
336 if ( isset( $merged_filters[ $tag ] ) ) {
337 unset( $merged_filters[ $tag ] );
344 * Retrieve the name of the current filter or action.
348 * @return string Hook name of the current filter or action.
350 function current_filter() {
351 global $wp_current_filter;
352 return end( $wp_current_filter );
356 * Retrieve the name of the current action.
360 * @uses current_filter()
362 * @return string Hook name of the current action.
364 function current_action() {
365 return current_filter();
369 * Retrieve the name of a filter currently being processed.
371 * The function current_filter() only returns the most recent filter or action
372 * being executed. did_action() returns true once the action is initially
375 * This function allows detection for any filter currently being
376 * executed (despite not being the most recent filter to fire, in the case of
377 * hooks called from hook callbacks) to be verified.
381 * @see current_filter()
383 * @global array $wp_current_filter Current filter.
385 * @param null|string $filter Optional. Filter to check. Defaults to null, which
386 * checks if any filter is currently being run.
387 * @return bool Whether the filter is currently in the stack.
389 function doing_filter( $filter = null ) {
390 global $wp_current_filter;
392 if ( null === $filter ) {
393 return ! empty( $wp_current_filter );
396 return in_array( $filter, $wp_current_filter );
400 * Retrieve the name of an action currently being processed.
404 * @uses doing_filter()
406 * @param string|null $action Optional. Action to check. Defaults to null, which checks
407 * if any action is currently being run.
408 * @return bool Whether the action is currently in the stack.
410 function doing_action( $action = null ) {
411 return doing_filter( $action );
415 * Hooks a function on to a specific action.
417 * Actions are the hooks that the WordPress core launches at specific points
418 * during execution, or when specific events occur. Plugins can specify that
419 * one or more of its PHP functions are executed at these points, using the
424 * @uses add_filter() Adds an action. Parameter list and functionality are the same.
426 * @param string $tag The name of the action to which the $function_to_add is hooked.
427 * @param callback $function_to_add The name of the function you wish to be called.
428 * @param int $priority Optional. Used to specify the order in which the functions
429 * associated with a particular action are executed. Default 10.
430 * Lower numbers correspond with earlier execution,
431 * and functions with the same priority are executed
432 * in the order in which they were added to the action.
433 * @param int $accepted_args Optional. The number of arguments the function accept. Default 1.
434 * @return bool Will always return true.
436 function add_action($tag, $function_to_add, $priority = 10, $accepted_args = 1) {
437 return add_filter($tag, $function_to_add, $priority, $accepted_args);
441 * Execute functions hooked on a specific action hook.
443 * This function invokes all functions attached to action hook $tag. It is
444 * possible to create new action hooks by simply calling this function,
445 * specifying the name of the new hook using the <tt>$tag</tt> parameter.
447 * You can pass extra arguments to the hooks, much like you can with
452 * @see apply_filters() This function works similar with the exception that nothing
453 * is returned and only the functions or methods are called.
454 * @global array $wp_filter Stores all of the filters
455 * @global array $wp_actions Increments the amount of times action was triggered.
457 * @param string $tag The name of the action to be executed.
458 * @param mixed $arg Optional. Additional arguments which are passed on to the
459 * functions hooked to the action. Default empty.
460 * @return null Will return null if $tag does not exist in $wp_filter array.
462 function do_action($tag, $arg = '') {
463 global $wp_filter, $wp_actions, $merged_filters, $wp_current_filter;
465 if ( ! isset($wp_actions[$tag]) )
466 $wp_actions[$tag] = 1;
470 // Do 'all' actions first
471 if ( isset($wp_filter['all']) ) {
472 $wp_current_filter[] = $tag;
473 $all_args = func_get_args();
474 _wp_call_all_hook($all_args);
477 if ( !isset($wp_filter[$tag]) ) {
478 if ( isset($wp_filter['all']) )
479 array_pop($wp_current_filter);
483 if ( !isset($wp_filter['all']) )
484 $wp_current_filter[] = $tag;
487 if ( is_array($arg) && 1 == count($arg) && isset($arg[0]) && is_object($arg[0]) ) // array(&$this)
491 for ( $a = 2; $a < func_num_args(); $a++ )
492 $args[] = func_get_arg($a);
495 if ( !isset( $merged_filters[ $tag ] ) ) {
496 ksort($wp_filter[$tag]);
497 $merged_filters[ $tag ] = true;
500 reset( $wp_filter[ $tag ] );
503 foreach ( (array) current($wp_filter[$tag]) as $the_ )
504 if ( !is_null($the_['function']) )
505 call_user_func_array($the_['function'], array_slice($args, 0, (int) $the_['accepted_args']));
507 } while ( next($wp_filter[$tag]) !== false );
509 array_pop($wp_current_filter);
513 * Retrieve the number of times an action is fired.
517 * @global array $wp_actions Increments the amount of times action was triggered.
519 * @param string $tag The name of the action hook.
520 * @return int The number of times action hook $tag is fired.
522 function did_action($tag) {
525 if ( ! isset( $wp_actions[ $tag ] ) )
528 return $wp_actions[$tag];
532 * Execute functions hooked on a specific action hook, specifying arguments in an array.
536 * @see do_action() This function is identical, but the arguments passed to the
537 * functions hooked to $tag< are supplied using an array.
538 * @global array $wp_filter Stores all of the filters
539 * @global array $wp_actions Increments the amount of times action was triggered.
541 * @param string $tag The name of the action to be executed.
542 * @param array $args The arguments supplied to the functions hooked to <tt>$tag</tt>
543 * @return null Will return null if $tag does not exist in $wp_filter array
545 function do_action_ref_array($tag, $args) {
546 global $wp_filter, $wp_actions, $merged_filters, $wp_current_filter;
548 if ( ! isset($wp_actions[$tag]) )
549 $wp_actions[$tag] = 1;
553 // Do 'all' actions first
554 if ( isset($wp_filter['all']) ) {
555 $wp_current_filter[] = $tag;
556 $all_args = func_get_args();
557 _wp_call_all_hook($all_args);
560 if ( !isset($wp_filter[$tag]) ) {
561 if ( isset($wp_filter['all']) )
562 array_pop($wp_current_filter);
566 if ( !isset($wp_filter['all']) )
567 $wp_current_filter[] = $tag;
570 if ( !isset( $merged_filters[ $tag ] ) ) {
571 ksort($wp_filter[$tag]);
572 $merged_filters[ $tag ] = true;
575 reset( $wp_filter[ $tag ] );
578 foreach( (array) current($wp_filter[$tag]) as $the_ )
579 if ( !is_null($the_['function']) )
580 call_user_func_array($the_['function'], array_slice($args, 0, (int) $the_['accepted_args']));
582 } while ( next($wp_filter[$tag]) !== false );
584 array_pop($wp_current_filter);
588 * Check if any action has been registered for a hook.
592 * @see has_filter() has_action() is an alias of has_filter().
594 * @param string $tag The name of the action hook.
595 * @param callback|bool $function_to_check Optional. The callback to check for. Default false.
596 * @return bool|int If $function_to_check is omitted, returns boolean for whether the hook has
597 * anything registered. When checking a specific function, the priority of that
598 * hook is returned, or false if the function is not attached. When using the
599 * $function_to_check argument, this function may return a non-boolean value
600 * that evaluates to false (e.g.) 0, so use the === operator for testing the
603 function has_action($tag, $function_to_check = false) {
604 return has_filter($tag, $function_to_check);
608 * Removes a function from a specified action hook.
610 * This function removes a function attached to a specified action hook. This
611 * method can be used to remove default functions attached to a specific filter
612 * hook and possibly replace them with a substitute.
616 * @param string $tag The action hook to which the function to be removed is hooked.
617 * @param callback $function_to_remove The name of the function which should be removed.
618 * @param int $priority Optional. The priority of the function. Default 10.
619 * @return boolean Whether the function is removed.
621 function remove_action( $tag, $function_to_remove, $priority = 10 ) {
622 return remove_filter( $tag, $function_to_remove, $priority );
626 * Remove all of the hooks from an action.
630 * @param string $tag The action to remove hooks from.
631 * @param int|bool $priority The priority number to remove them from. Default false.
632 * @return bool True when finished.
634 function remove_all_actions($tag, $priority = false) {
635 return remove_all_filters($tag, $priority);
639 // Functions for handling plugins.
643 * Gets the basename of a plugin.
645 * This method extracts the name of a plugin from its filename.
649 * @uses WP_PLUGIN_DIR, WPMU_PLUGIN_DIR
651 * @param string $file The filename of plugin.
652 * @return string The name of a plugin.
654 function plugin_basename( $file ) {
655 global $wp_plugin_paths;
657 foreach ( $wp_plugin_paths as $dir => $realdir ) {
658 if ( strpos( $file, $realdir ) === 0 ) {
659 $file = $dir . substr( $file, strlen( $realdir ) );
663 $file = wp_normalize_path( $file );
664 $plugin_dir = wp_normalize_path( WP_PLUGIN_DIR );
665 $mu_plugin_dir = wp_normalize_path( WPMU_PLUGIN_DIR );
667 $file = preg_replace('#^' . preg_quote($plugin_dir, '#') . '/|^' . preg_quote($mu_plugin_dir, '#') . '/#','',$file); // get relative path from plugins dir
668 $file = trim($file, '/');
673 * Register a plugin's real path.
675 * This is used in plugin_basename() to resolve symlinked paths.
679 * @see plugin_basename()
681 * @param string $file Known path to the file.
682 * @return bool Whether the path was able to be registered.
684 function wp_register_plugin_realpath( $file ) {
685 global $wp_plugin_paths;
687 // Normalize, but store as static to avoid recalculation of a constant value
688 static $wp_plugin_path, $wpmu_plugin_path;
689 if ( ! isset( $wp_plugin_path ) ) {
690 $wp_plugin_path = wp_normalize_path( WP_PLUGIN_DIR );
691 $wpmu_plugin_path = wp_normalize_path( WPMU_PLUGIN_DIR );
694 $plugin_path = wp_normalize_path( dirname( $file ) );
695 $plugin_realpath = wp_normalize_path( dirname( realpath( $file ) ) );
697 if ( $plugin_path === $wp_plugin_path || $plugin_path === $wpmu_plugin_path ) {
701 if ( $plugin_path !== $plugin_realpath ) {
702 $wp_plugin_paths[ $plugin_path ] = $plugin_realpath;
709 * Get the filesystem directory path (with trailing slash) for the plugin __FILE__ passed in.
713 * @param string $file The filename of the plugin (__FILE__).
714 * @return string the filesystem path of the directory that contains the plugin.
716 function plugin_dir_path( $file ) {
717 return trailingslashit( dirname( $file ) );
721 * Get the URL directory path (with trailing slash) for the plugin __FILE__ passed in.
725 * @param string $file The filename of the plugin (__FILE__).
726 * @return string the URL path of the directory that contains the plugin.
728 function plugin_dir_url( $file ) {
729 return trailingslashit( plugins_url( '', $file ) );
733 * Set the activation hook for a plugin.
735 * When a plugin is activated, the action 'activate_PLUGINNAME' hook is
736 * called. In the name of this hook, PLUGINNAME is replaced with the name
737 * of the plugin, including the optional subdirectory. For example, when the
738 * plugin is located in wp-content/plugins/sampleplugin/sample.php, then
739 * the name of this hook will become 'activate_sampleplugin/sample.php'.
741 * When the plugin consists of only one file and is (as by default) located at
742 * wp-content/plugins/sample.php the name of this hook will be
743 * 'activate_sample.php'.
747 * @param string $file The filename of the plugin including the path.
748 * @param callback $function The function hooked to the 'activate_PLUGIN' action.
750 function register_activation_hook($file, $function) {
751 $file = plugin_basename($file);
752 add_action('activate_' . $file, $function);
756 * Set the deactivation hook for a plugin.
758 * When a plugin is deactivated, the action 'deactivate_PLUGINNAME' hook is
759 * called. In the name of this hook, PLUGINNAME is replaced with the name
760 * of the plugin, including the optional subdirectory. For example, when the
761 * plugin is located in wp-content/plugins/sampleplugin/sample.php, then
762 * the name of this hook will become 'deactivate_sampleplugin/sample.php'.
764 * When the plugin consists of only one file and is (as by default) located at
765 * wp-content/plugins/sample.php the name of this hook will be
766 * 'deactivate_sample.php'.
770 * @param string $file The filename of the plugin including the path.
771 * @param callback $function The function hooked to the 'deactivate_PLUGIN' action.
773 function register_deactivation_hook($file, $function) {
774 $file = plugin_basename($file);
775 add_action('deactivate_' . $file, $function);
779 * Set the uninstallation hook for a plugin.
781 * Registers the uninstall hook that will be called when the user clicks on the
782 * uninstall link that calls for the plugin to uninstall itself. The link won't
783 * be active unless the plugin hooks into the action.
785 * The plugin should not run arbitrary code outside of functions, when
786 * registering the uninstall hook. In order to run using the hook, the plugin
787 * will have to be included, which means that any code laying outside of a
788 * function will be run during the uninstall process. The plugin should not
789 * hinder the uninstall process.
791 * If the plugin can not be written without running code within the plugin, then
792 * the plugin should create a file named 'uninstall.php' in the base plugin
793 * folder. This file will be called, if it exists, during the uninstall process
794 * bypassing the uninstall hook. The plugin, when using the 'uninstall.php'
795 * should always check for the 'WP_UNINSTALL_PLUGIN' constant, before
800 * @param string $file Plugin file.
801 * @param callback $callback The callback to run when the hook is called. Must be
802 * a static method or function.
804 function register_uninstall_hook( $file, $callback ) {
805 if ( is_array( $callback ) && is_object( $callback[0] ) ) {
806 _doing_it_wrong( __FUNCTION__, __( 'Only a static class method or function can be used in an uninstall hook.' ), '3.1' );
811 * The option should not be autoloaded, because it is not needed in most
812 * cases. Emphasis should be put on using the 'uninstall.php' way of
813 * uninstalling the plugin.
815 $uninstallable_plugins = (array) get_option('uninstall_plugins');
816 $uninstallable_plugins[plugin_basename($file)] = $callback;
818 update_option('uninstall_plugins', $uninstallable_plugins);
822 * Call the 'all' hook, which will process the functions hooked into it.
824 * The 'all' hook passes all of the arguments or parameters that were used for
825 * the hook, which this function was called for.
827 * This function is used internally for apply_filters(), do_action(), and
828 * do_action_ref_array() and is not meant to be used from outside those
829 * functions. This function does not check for the existence of the all hook, so
830 * it will fail unless the all hook exists prior to this function call.
835 * @uses $wp_filter Used to process all of the functions in the 'all' hook.
837 * @param array $args The collected parameters from the hook that was called.
839 function _wp_call_all_hook($args) {
842 reset( $wp_filter['all'] );
844 foreach( (array) current($wp_filter['all']) as $the_ )
845 if ( !is_null($the_['function']) )
846 call_user_func_array($the_['function'], $args);
848 } while ( next($wp_filter['all']) !== false );
852 * Build Unique ID for storage and retrieval.
854 * The old way to serialize the callback caused issues and this function is the
855 * solution. It works by checking for objects and creating an a new property in
856 * the class to keep track of the object and new objects of the same class that
859 * It also allows for the removal of actions and filters for objects after they
860 * change class properties. It is possible to include the property $wp_filter_id
861 * in your class and set it to "null" or a number to bypass the workaround.
862 * However this will prevent you from adding new classes and any new classes
863 * will overwrite the previous hook by the same class.
865 * Functions and static method callbacks are just returned as strings and
866 * shouldn't have any speed penalty.
868 * @link http://trac.wordpress.org/ticket/3875
873 * @global array $wp_filter Storage for all of the filters and actions.
875 * @param string $tag Used in counting how many hooks were applied
876 * @param callback $function Used for creating unique id
877 * @param int|bool $priority Used in counting how many hooks were applied. If === false
878 * and $function is an object reference, we return the unique
879 * id only if it already has one, false otherwise.
880 * @return string|bool Unique ID for usage as array key or false if $priority === false
881 * and $function is an object reference, and it does not already have
884 function _wp_filter_build_unique_id($tag, $function, $priority) {
886 static $filter_id_count = 0;
888 if ( is_string($function) )
891 if ( is_object($function) ) {
892 // Closures are currently implemented as objects
893 $function = array( $function, '' );
895 $function = (array) $function;
898 if (is_object($function[0]) ) {
899 // Object Class Calling
900 if ( function_exists('spl_object_hash') ) {
901 return spl_object_hash($function[0]) . $function[1];
903 $obj_idx = get_class($function[0]).$function[1];
904 if ( !isset($function[0]->wp_filter_id) ) {
905 if ( false === $priority )
907 $obj_idx .= isset($wp_filter[$tag][$priority]) ? count((array)$wp_filter[$tag][$priority]) : $filter_id_count;
908 $function[0]->wp_filter_id = $filter_id_count;
911 $obj_idx .= $function[0]->wp_filter_id;
916 } else if ( is_string($function[0]) ) {
918 return $function[0] . '::' . $function[1];