/**
* 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.
*
* To remove a hook, the $function_to_remove and $priority arguments must match
* when the hook was added. This goes for both filters and actions. No warning
* will be given on removal failure.
*
* @author WordPress
* @global array $filters Stores all of the filters
*
* @param string $filter 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 $priority optional. The priority of the function (default: 10).
* @return boolean Whether the function existed before it was removed.
*/
function remove_filter($filter, $function_to_remove, $priority = 10)
{
$function_to_remove = _build_callback_string($function_to_remove);
$r = isset($GLOBALS['filters'][$filter][$priority][$function_to_remove]);
if (true === $r) {
unset($GLOBALS['filters'][$filter][$priority][$function_to_remove]);
if (empty($GLOBALS['filters'][$filter][$priority])) {
unset($GLOBALS['filters'][$filter][$priority]);
}
}
return $r;
}
/**
* Hooks a function or method to a specific filter action.
*
* Filters are the hooks that Lilina launches to modify text of various types
* before adding it to the database or sending it to the browser screen. Plugins
* can specify that one or more of its PHP functions is executed to
* modify specific types of text at these times, using the Filter API.
*
* To use the API, the following code should be used to bind a callback to the
* filter.
*
* <code>
* function example_hook($example) { echo $example; }
* add_filter('example_filter', 'example_hook');
* </code>
*
* 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. The
* $accepted_args allow for calling functions only when the number of args
* match. Hooked functions can take extra arguments that are set when the
* matching do_action() or apply_filters() call is run. For example, the action
* comment_id_not_found will pass any functions that hook onto it the ID of the
* requested comment.
*
* <strong>Note:</strong> the function will return true no matter if the
* function was hooked fails or not. There are no checks for whether the
* function exists beforehand and no checks to whether the <tt>$function_to_add
* is even a string. It is up to you to take care and this is done for
* optimization purposes, so everything is as quick as possible.
*
* @author WordPress
* @global array $filters Stores all of the filters added in the form of
* filters['tag']['array of priorities']['array of functions serialized']['array of ['array (functions, accepted_args)']']
*
* @param string $filter The name of the filter to hook the $function_to_add to.
* @param callback $function 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 $num_args optional. The number of arguments the function accept (default 1).
* @return boolean true
*/
function add_filter($filter, $function, $priority = 10, $num_args = 1)
{
global $filters;
$id = _build_callback_string($function);
$filters[$filter][$priority][$id] = array('function' => $function, 'num_args' => $num_args);
return true;
}