How to use list_terms_exclusions filter in WordPress

list_terms_exclusions filter

Filters the terms to exclude from the terms query.

To use list_terms_exclusions filter, first you have to register it using add_filter. You can write this code into the 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 modify_list_terms_exclusions_defaults which takes 3 parameters and we registered using add_filter. The first parameter list_terms_exclusions is the name of the hook, The second parameter modify_list_terms_exclusions_defaults 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.

Sometime, you have to remove a registered hook so you can use remove_filter to remove the list_terms_exclusions filter.

Parameters

Below are the 3 parameters required to use this hook.

• $exclusions : (string) NOT IN clause of the terms query.
• $args : (array) An array of terms query arguments.
• $taxonomies : (string[]) An array of taxonomy names.

Live Example

apply_filters( 'list_terms_exclusions', string $exclusions, array $args, string[] $taxonomies )

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

Example 1: Basic Usage

This example demonstrates how to modify the $exclusions variable according to your website’s requirements.

    function weplugins_modify_list_terms_exclusions_defaults($exclusions, $args, $taxonomies) { 
        // Update the $exclusions variable according to your website requirements and return this variable. You can modify the $exclusions variable conditionally too if you want.
        return $exclusions; 
    }
    // add the filter
    add_filter( "list_terms_exclusions", "weplugins_modify_list_terms_exclusions_defaults", 10, 3 );
    

Example 2: Conditional Exclusions

This example shows how to modify the $exclusions variable conditionally based on specific taxonomies.

    function weplugins_conditional_list_terms_exclusions($exclusions, $args, $taxonomies) { 
        if (in_array('category', $taxonomies)) {
            // Exclude specific categories
            $exclusions .= " AND t.term_id NOT IN (1, 2, 3)";
        }
        return $exclusions; 
    }
    // add the filter
    add_filter( "list_terms_exclusions", "weplugins_conditional_list_terms_exclusions", 10, 3 );
    

Example 3: Remove Hook

To remove a hook callback, use the example below. Ensure to provide the same callback function name, priority, and number of arguments while removing the hook callback.

    // remove the filter
    remove_filter( "list_terms_exclusions", "weplugins_modify_list_terms_exclusions_defaults", 10, 3 );
    

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