How to use Actions and Filters

Hooks in WordPress essentially allow you to change or add code without editing core files. They are used extensively throughout WordPress and EventON and are very useful for developers.

There are two types of hook: actions and filters.

• Action Hooks allow you to insert custom code at various points (wherever the hook is run).
• Filter Hooks allow you to manipulate and return a variable which it passes (for instance a product price).

Here is an excellent article on hooks and filters here,.

 

Using Hooks

If you use a hook to add or manipulate code, you can add your custom code to your theme’s functions.php file.

Using action hooks

To execute your own code, you hook in by using the action hook do_action('action_name');. Here is where to place your code:

add_action( 'action_name', 'your_function_name' );

function your_function_name() {
// Your code
}

Using filter hooks

Filter hooks are called throughout are code using apply_filter( 'filter_name', $variable );. To manipulate the passed variable, you can do something like the following:

add_filter( 'filter_name', 'your_function_name' );

function your_function_name( $variable ) {
// Your code
return $variable;
}

With filters, you must return a value.

Available EventON Action and filter hooks