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The plugin API is located in this file, which allows for creating actions and filters and hooking functions, and methods. The functions or methods will then be run when the action or filter is called. The API callback examples reference functions, but can be methods of classes. To hook methods, you'll need to pass an array one of two ways.
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| add_filter( $tag, $function_to_add, $priority = 10, $accepted_args = 1 ) X-Ref |
| Hooks a function or method to a specific filter action. WordPress offers filter hooks to allow plugins to modify various types of internal data at runtime. A plugin can modify data by binding a callback to a filter hook. When the filter is later applied, each bound callback is run in order of priority, and given the opportunity to modify a value by returning a new value. The following example shows how a callback function is bound to a filter hook. Note that $example is passed to the callback, (maybe) modified, then returned: <code> function example_callback( $example ) { // Maybe modify $example in some way return $example; } add_filter( 'example_filter', 'example_callback' ); </code> Since WordPress 1.5.1, bound callbacks can take as many arguments as are passed as parameters in the corresponding apply_filters() call. The $accepted_args parameter allows for calling functions only when the number of args match. <strong>Note:</strong> the function will return true whether or not the callback is valid. It is up to you to take care. This is done for optimization purposes, so everything is as quick as possible. param: string $tag The name of the filter to hook the $function_to_add callback to. param: callback $function_to_add The callback to be run when the filter is applied. param: int $priority (optional) The order in which the functions associated with a particular action are executed. 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 $accepted_args (optional) The number of arguments the function accepts. return: boolean true |
| has_filter($tag, $function_to_check = false) X-Ref |
| Check if any filter has been registered for a hook. param: string $tag The name of the filter hook. param: callback $function_to_check optional. return: mixed If $function_to_check is omitted, returns boolean for whether the hook has anything registered. |
| apply_filters( $tag, $value ) X-Ref |
| 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. The function allows for additional arguments to be added and passed to hooks. <code> // Our filter callback function function example_callback( $string, $arg1, $arg2 ) { // (maybe) modify $string return $string; } add_filter( 'example_filter', 'example_callback', 10, 3 ); // Apply the filters by calling the 'example_callback' function we // "hooked" to 'example_filter' using the add_filter() function above. // - 'example_filter' is the filter hook $tag // - 'filter me' is the value being filtered // - $arg1 and $arg2 are the additional arguments passed to the callback. $value = apply_filters( 'example_filter', 'filter me', $arg1, $arg2 ); </code> param: string $tag The name of the filter hook. param: mixed $value The value on which the filters hooked to <tt>$tag</tt> are applied on. param: mixed $var Additional variables passed to the functions hooked to <tt>$tag</tt>. return: mixed The filtered value after all hooked functions are applied to it. |
| apply_filters_ref_array($tag, $args) X-Ref |
| Execute functions hooked on a specific filter hook, specifying arguments in an array. param: string $tag The name of the filter hook. param: array $args The arguments supplied to the functions hooked to <tt>$tag</tt> return: mixed The filtered value after all hooked functions are applied to it. |
| remove_filter( $tag, $function_to_remove, $priority = 10 ) X-Ref |
| 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. 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 $accepted_args optional. The number of arguments the function accepts (default: 1). return: boolean Whether the function existed before it was removed. |
| remove_all_filters($tag, $priority = false) X-Ref |
| Remove all of the hooks from a filter. param: string $tag The filter to remove hooks from. param: int $priority The priority number to remove. return: bool True when finished. |
| current_filter() X-Ref |
| Retrieve the name of the current filter or action. return: string Hook name of the current filter or action. |
| add_action($tag, $function_to_add, $priority = 10, $accepted_args = 1) X-Ref |
| 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. 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 $accepted_args optional. The number of arguments the function accept (default 1). |
| do_action($tag, $arg = '') X-Ref |
| Execute functions hooked on a specific action hook. This function invokes all functions attached to action hook $tag. It is possible to create new action hooks by simply calling this function, specifying the name of the new hook using the <tt>$tag</tt> parameter. You can pass extra arguments to the hooks, much like you can with apply_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. return: null Will return null if $tag does not exist in $wp_filter array |
| did_action($tag) X-Ref |
| Retrieve the number of times an action is fired. param: string $tag The name of the action hook. return: int The number of times action hook <tt>$tag</tt> is fired |
| do_action_ref_array($tag, $args) X-Ref |
| Execute functions hooked on a specific action hook, specifying arguments in an array. param: string $tag The name of the action to be executed. param: array $args The arguments supplied to the functions hooked to <tt>$tag</tt> return: null Will return null if $tag does not exist in $wp_filter array |
| has_action($tag, $function_to_check = false) X-Ref |
| Check if any action has been registered for a hook. param: string $tag The name of the action hook. param: callback $function_to_check optional. return: mixed If $function_to_check is omitted, returns boolean for whether the hook has anything registered. |
| remove_action( $tag, $function_to_remove, $priority = 10 ) X-Ref |
| 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 $priority optional The priority of the function (default: 10). return: boolean Whether the function is removed. |
| remove_all_actions($tag, $priority = false) X-Ref |
| Remove all of the hooks from an action. param: string $tag The action to remove hooks from. param: int $priority The priority number to remove them from. return: bool True when finished. |
| plugin_basename($file) X-Ref |
| Gets the basename of a plugin. This method extracts the name of a plugin from its filename. param: string $file The filename of plugin. return: string The name of a plugin. |
| plugin_dir_path( $file ) X-Ref |
| Gets the filesystem directory path (with trailing slash) for the plugin __FILE__ passed in param: string $file The filename of the plugin (__FILE__) return: string the filesystem path of the directory that contains the plugin |
| plugin_dir_url( $file ) X-Ref |
| Gets the URL directory path (with trailing slash) for the plugin __FILE__ passed in param: string $file The filename of the plugin (__FILE__) return: string the URL path of the directory that contains the plugin |
| register_activation_hook($file, $function) X-Ref |
| Set the activation hook for a plugin. When a plugin is activated, the action 'activate_PLUGINNAME' hook is called. 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/plugins/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/plugins/sample.php the name of this hook will be 'activate_sample.php'. param: string $file The filename of the plugin including the path. param: callback $function the function hooked to the 'activate_PLUGIN' action. |
| register_deactivation_hook($file, $function) X-Ref |
| Set the deactivation hook for a plugin. When a plugin is deactivated, the action 'deactivate_PLUGINNAME' hook is called. 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/plugins/sampleplugin/sample.php, then the name of this hook will become 'deactivate_sampleplugin/sample.php'. When the plugin consists of only one file and is (as by default) located at wp-content/plugins/sample.php the name of this hook will be 'deactivate_sample.php'. param: string $file The filename of the plugin including the path. param: callback $function the function hooked to the 'deactivate_PLUGIN' action. |
| register_uninstall_hook( $file, $callback ) X-Ref |
| Set the uninstallation hook for a plugin. Registers the uninstall hook that will be called when the user clicks on the uninstall link that calls for the plugin to uninstall itself. The link won't be active unless the plugin hooks into the action. The plugin should not run arbitrary code outside of functions, when registering the uninstall hook. In order to run using the hook, the plugin will have to be included, which means that any code laying outside of a function will be run during the uninstall process. The plugin should not hinder the uninstall process. If the plugin can not be written without running code within the plugin, then the plugin should create a file named 'uninstall.php' in the base plugin folder. This file will be called, if it exists, during the uninstall process bypassing the uninstall hook. The plugin, when using the 'uninstall.php' should always check for the 'WP_UNINSTALL_PLUGIN' constant, before executing. param: string $file param: callback $callback The callback to run when the hook is called. Must be a static method or function. |
| _wp_call_all_hook($args) X-Ref |
| Calls the 'all' hook, which will process the functions hooked into it. The 'all' hook passes all of the arguments or parameters that were used for the hook, which this function was called for. This function is used internally for apply_filters(), do_action(), and do_action_ref_array() and is not meant to be used from outside those functions. This function does not check for the existence of the all hook, so it will fail unless the all hook exists prior to this function call. param: array $args The collected parameters from the hook that was called. |
| _wp_filter_build_unique_id($tag, $function, $priority) X-Ref |
| Build Unique ID for storage and retrieval. The old way to serialize the callback caused issues and this function is the solution. It works by checking for objects and creating an a new property in the class to keep track of the object and new objects of the same class that need to be added. It also allows for the removal of actions and filters for objects after they change class properties. It is possible to include the property $wp_filter_id in your class and set it to "null" or a number to bypass the workaround. However this will prevent you from adding new classes and any new classes will overwrite the previous hook by the same class. Functions and static method callbacks are just returned as strings and shouldn't have any speed penalty. param: string $tag Used in counting how many hooks were applied param: callback $function Used for creating unique id param: int|bool $priority Used in counting how many hooks were applied. If === false and $function is an object reference, we return the unique id only if it already has one, false otherwise. return: string|bool Unique ID for usage as array key or false if $priority === false and $function is an object reference, and it does not already have a unique id. |
| Generated: Tue Mar 25 01:41:18 2014 | WordPress honlapkészítés: online1.hu |