How to use pre_get_terms action in WordPress

pre_get_terms action

Fires before terms are retrieved.

To use the pre_get_terms action, first you have to register it using add_action. You can write this code into functions.php of your activated theme or in a custom WordPress Plugin.

We at WePlugins always prefer to create a custom WordPress Plugin while using hooks so nothing breaks when you update your WordPress Theme in the future.

In the below live example, we have defined a function weplugins_execute_on_pre_get_terms_event which takes 1 parameter and we registered it using add_action. The first parameter pre_get_terms is the name of the hook, the second parameter weplugins_execute_on_pre_get_terms_event is the name of the function which needs to be called, the third parameter is the priority of calling the hook if the same hook is used multiple times, and the last parameter is the number of arguments (if any) to be passed in the registered function.

Sometimes, you have to remove a registered hook, so you can use remove_action to remove the pre_get_terms action.

Parameters

Below the 1 parameter is required to use this hook.

• $query: (WP_Term_Query) Current instance of WP_Term_Query (passed by reference).

Live Example 1

Below is an example of how you can use this hook.

function weplugins_execute_on_pre_get_terms_event($query){
   // You can write code here to be executed when this action occurs in WordPress.
   // Use the parameters received in the function arguments & implement the required additional custom functionality according to your website requirements.
}
// Add the action
add_action("pre_get_terms", "weplugins_execute_on_pre_get_terms_event", 10, 1);

Live Example 2

To remove a hook callback, use the example below.

remove_action("pre_get_terms", "weplugins_execute_on_pre_get_terms_event", 10, 1);

Please make sure to provide the same callback function name, priority, and number of arguments while removing the hook callback.

Live Example 3

Another practical use case could be filtering terms based on custom criteria before they are displayed.

function weplugins_filter_terms_before_display($query){
   if (!is_admin() && $query->is_main_query()) {
       // Modify the query as needed
       $query->set('taxonomy', 'category'); // Just an example
   }
}
add_action('pre_get_terms', 'weplugins_filter_terms_before_display');

Contact Us

If you’re having any trouble using this hook or need any customization, please contact us and we’d be happy to assist you.