$function_to_add to. * @param callback $function_to_add The name of the function to be called when the filter is applied. * @param int $priority optional. Used to specify the order in which the functions associated with a particular action are executed (default: 10). Lower numbers correspond with earlier execution, and functions with the same priority are executed in the order in which they were added to the action. * @param int $accepted_args optional. The number of arguments the function accept (default 1). In WordPress 1.5.1+, hooked functions can take extra arguments that are set when the matching do_action() or apply_filters() call is run. * @return boolean true if the $function_to_add is added succesfully to filter $tag. How many arguments your function takes. In WordPress 1.5.1+, hooked functions can take extra arguments that are set when the matching do_action() or apply_filters() call is run. For example, the action comment_id_not_found will pass any functions that hook onto it the ID of the requested comment. */ function add_filter($tag, $function_to_add, $priority = 10, $accepted_args = 1) { global $wp_filter; // So the format is wp_filter['tag']['array of priorities']['array of functions serialized']['array of ['array (functions, accepted_args)]'] $wp_filter[$tag][$priority][serialize($function_to_add)] = array('function' => $function_to_add, 'accepted_args' => $accepted_args); return true; } /** * Call the functions added to a filter hook. * * The callback functions attached to filter hook $tag are invoked by * calling this function. This function can be used to create a new filter hook * by simply calling this function with the name of the new hook specified using * the $tag parameter. * @uses merge_filters Merges the filter hooks using this function. * @param string $tag The name of the filter hook. * @param string $string The text on which the filters hooked to $tag are applied on. * @param mixed $var,... Additional variables passed to the functions hooked to $tag. * @return string The text in $string after all hooked functions are applied to it. */ function apply_filters($tag, $string) { global $wp_filter; merge_filters($tag); if ( !isset($wp_filter[$tag]) ) return $string; $args = func_get_args(); do{ foreach( (array) current($wp_filter[$tag]) as $the_ ) if ( !is_null($the_['function']) ){ $args[1] = $string; $string = call_user_func_array($the_['function'], array_slice($args, 1, (int) $the_['accepted_args'])); } } while ( next($wp_filter[$tag]) ); return $string; } /** * Merge the filter functions of a specific filter hook with generic filter functions. * * It is possible to defined generic filter functions using the filter hook * all. These functions are called for every filter tag. This function * merges the functions attached to the all hook with the functions * of a specific hoook defined by $tag. * @param string $tag The filter hook of which the functions should be merged. */ function merge_filters($tag) { global $wp_filter; if ( isset($wp_filter['all']) ) $wp_filter[$tag] = array_merge($wp_filter['all'], (array) $wp_filter[$tag]); if ( isset($wp_filter[$tag]) ){ reset($wp_filter[$tag]); uksort($wp_filter[$tag], "strnatcasecmp"); } } /** * Removes a function from a specified filter hook. * * This function removes a function attached to a specified filter hook. This * method can be used to remove default functions attached to a specific filter * hook and possibly replace them with a substitute. * @param string $tag The filter hook to which the function to be removed is hooked. * @param callback $function_to_remove The name of the function which should be removed. * @param int $priority optional. The priority of the function (default: 10). * @param int $accepted_args optional. The number of arguments the function accpets (default: 1). * @return boolean Whether the function is removed. */ function remove_filter($tag, $function_to_remove, $priority = 10, $accepted_args = 1) { global $wp_filter; unset($GLOBALS['wp_filter'][$tag][$priority][serialize($function_to_remove)]); return true; } /** * Hooks a function on to a specific action. * * Actions are the hooks that the WordPress core launches at specific points * during execution, or when specific events occur. Plugins can specify that * one or more of its PHP functions are executed at these points, using the * Action API. * * @param string $tag The name of the action to which the $function_to-add is hooked. * @param callback $function_to_add The name of the function you wish to be called. Note: any of the syntaxes explained in the PHP documentation for the 'callback' type (http://us2.php.net/manual/en/language.pseudo-types.php#language.types.callback) are valid. * @param int $priority optional. Used to specify the order in which the functions associated with a particular action are executed (default: 10). Lower numbers correspond with earlier execution, and functions with the same priority are executed in the order in which they were added to the action. * @param int $accepted_args optional. The number of arguments the function accept (default 1). In WordPress 1.5.1+, hooked functions can take extra arguments that are set when the matching do_action() or apply_filters() call is run. * @return boolean Always true. */ function add_action($tag, $function_to_add, $priority = 10, $accepted_args = 1) { add_filter($tag, $function_to_add, $priority, $accepted_args); } /** * Execute functions hooked on a specific action hook. * * This function invokes all functions attached to action hook $tag. * It is possible to create new action hooks by simply calling this function, * specifying the name of the new hook using the $tag parameter. * @uses merge_filters * @param string $tag The name of the action to be executed. * @param mixed $arg,... Optional additional arguments which are passed on to the functions hooked to the action. */ function do_action($tag, $arg = '') { global $wp_filter, $wp_actions; $args = array(); if ( is_array($arg) && 1 == count($arg) && is_object($arg[0]) ) // array(&$this) $args[] =& $arg[0]; else $args[] = $arg; for ( $a = 2; $a < func_num_args(); $a++ ) $args[] = func_get_arg($a); merge_filters($tag); if ( !isset($wp_filter[$tag]) ) return; do{ foreach( (array) current($wp_filter[$tag]) as $the_ ) if ( !is_null($the_['function']) ) call_user_func_array($the_['function'], array_slice($args, 0, (int) $the_['accepted_args'])); } while ( next($wp_filter[$tag]) ); if ( is_array($wp_actions) ) $wp_actions[] = $tag; else $wp_actions = array($tag); } /** * Return the number of functions hooked to a specific action hook. * @param string $tag The name of the action hook. * @return int The number of functions hooked to action hook $tag */ function did_action($tag) { global $wp_actions; return count(array_keys($wp_actions, $tag)); } /** * Execute functions hooked on a specific action hook, specifying arguments in a array. * * This function is identical to {@link do_action}, but the argumetns passe to * the functions hooked to $tag are supplied using an array. * @param string $tag The name of the action to be executed. * @param array $args The arguments supplied to the functions hooked to $tag */ function do_action_ref_array($tag, $args) { global $wp_filter, $wp_actions; if ( !is_array($wp_actions) ) $wp_actions = array($tag); else $wp_actions[] = $tag; merge_filters($tag); if ( !isset($wp_filter[$tag]) ) return; do{ foreach( (array) current($wp_filter[$tag]) as $the_ ) if ( !is_null($the_['function']) ) call_user_func_array($the_['function'], array_slice($args, 0, (int) $the_['accepted_args'])); } while ( next($wp_filter[$tag]) ); } /** * Removes a function from a specified action hook. * * This function removes a function attached to a specified action hook. This * method can be used to remove default functions attached to a specific filter * hook and possibly replace them with a substitute. * @param string $tag The action hook to which the function to be removed is hooked. * @param callback $function_to_remove The name of the function which should be removed. * @param int $priority optional The priority of the function (default: 10). * @param int $accepted_args optional. The number of arguments the function accpets (default: 1). * @return boolean Whether the function is removed. */ function remove_action($tag, $function_to_remove, $priority = 10, $accepted_args = 1) { remove_filter($tag, $function_to_remove, $priority, $accepted_args); } // // Functions for handling plugins. // /** * Gets the basename of a plugin. * * This method extract the name of a plugin from its filename. * @param string $file The filename of plugin. * @return string The name of a plugin. */ function plugin_basename($file) { $file = preg_replace('|\\\\+|', '\\\\', $file); $file = preg_replace('/^.*wp-content[\\\\\/]plugins[\\\\\/]/', '', $file); return $file; } /** * Hook a function on a plugin activation action hook. * * When a plugin is activated, the action 'activate_PLUGINNAME' hook is * activated. In the name of this hook, PLUGINNAME is replaced with the name of * the plugin, including the optional subdirectory. For example, when the plugin * is located in wp-content/plugin/sampleplugin/sample.php, then the * name of this hook will become 'activate_sampleplugin/sample.php'. * When the plugin consists of only one file and is (as by default) located at * wp-content/plugin/sample.php the name of this hook will be * 'activate_sample.php'. * @param string $file The filename of the plugin including the path. * @param string $function the function hooked to the 'activate_PLUGIN' action. */ function register_activation_hook($file, $function) { $file = plugin_basename($file); add_action('activate_' . $file, $function); } /** * Hook a function on a plugin deactivation action hook. * * When a plugin is deactivated, the action 'deactivate_PLUGINNAME' hook is * deactivated. In the name of this hook, PLUGINNAME is replaced with the name of * the plugin, including the optional subdirectory. For example, when the plugin * is located in wp-content/plugin/sampleplugin/sample.php, then the * name of this hook will become 'activate_sampleplugin/sample.php'. * When the plugin consists of only one file and is (as by default) located at * wp-content/plugin/sample.php the name of this hook will be * 'activate_sample.php'. * @param string $file The filename of the plugin including the path. * @param string $function the function hooked to the 'activate_PLUGIN' action. */ function register_deactivation_hook($file, $function) { $file = plugin_basename($file); add_action('deactivate_' . $file, $function); } ?>