WP_CLI::add_wp_hook PHP Method

add_wp_hook() public static method

add_action() without needing access to add_action(). If WordPress is already loaded though, you should use add_action() (and add_filter()) instead.
public static add_wp_hook ( string $tag, mixed $function_to_add, integer $priority = 10, integer $accepted_args = 1 ) : true
$tag string Named WordPress action or filter.
$function_to_add mixed Callable to execute when the action or filter is evaluated.
$priority integer Priority to add the callback as.
$accepted_args integer Number of arguments to pass to callback.
return true
    public static function add_wp_hook($tag, $function_to_add, $priority = 10, $accepted_args = 1)
    {
        global $wp_filter, $merged_filters;
        if (function_exists('add_filter')) {
            add_filter($tag, $function_to_add, $priority, $accepted_args);
        } else {
            $idx = self::wp_hook_build_unique_id($tag, $function_to_add, $priority);
            $wp_filter[$tag][$priority][$idx] = array('function' => $function_to_add, 'accepted_args' => $accepted_args);
            unset($merged_filters[$tag]);
        }
        return true;
    }