Each time I have to add an ajax function in a WordPress plugin, I lost time to know what is the problem. So I decided to wrap

add_action("wp_ajax{$function_name }", array( $function_class, $function_name ) )

with a function which check if there is an error.

This is the actual list of reasons why wp_ajax won´t be correctly called :

• The file where there is the php ajax function does not exist

• The class where there is the ajax function is not included before doing

  add_action("wp_ajax{$function_name }", array( $function_class, $function_name ) ) 
  

• The function or the method inside the class does not exist.

• The ajax function is added in the wrong moment. If you use a hook like this :

  add_action( "wp_loaded", array( $this, "add_wp_ajax_functions" ) );
  

  and add

  add_action("wp_ajax{$function_name }", array( $function_class, $function_name ) )
  

  inside add_wp_ajax_functions() that works, but not for all hooks of course.

So, my question is about the last list point. Which hooks are allowed to use the function add_wp_ajax_functions().

For the moment I know that :

Right hooks

• wp_loaded
• ?

Wrong hooks

• ?

I saw "If you look into this file wp-admin/admin-ajax.php where the wp_ajax_ actions are called, you will find that the admin_init action is being called before it."

So should have added wp_ajax functions before admin_init ?