How to use locale filter in WordPress

Hey there! If you’re working with WordPress hooks, you’re in the right place. Today, let’s dive into the locale filter. This hook is used to filter the locale ID of your WordPress installation. First, you’ll need to register it using add_filter. You can put this code in the functions.php file of your active theme or, better yet, in a custom WordPress plugin. At WePlugins, we always recommend creating a custom plugin to ensure nothing breaks when you update your theme.

In the following examples, we’ll define a function weplugins_modify_locale_defaults which takes one parameter. We’ll register this function using add_filter. The first parameter, locale, is the name of the hook. The second parameter, weplugins_modify_locale_defaults, is the name of the function 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 to the registered function.

Sometimes, you may need to remove a registered hook. You can use remove_filter to remove the locale filter.

Parameters

Below is the required parameter to use this hook:

• $locale: (string) The locale ID.

Live Example 1: Forcing English in Admin Area

This example demonstrates how to force English (en_US) in the WordPress admin area.

        /*
        Plugin Name: English Only Admin
        Plugin URI: http://your-domain.com
        Description: Force English (en_US) in the WordPress Admin
        Version: 1.0
        Author: You
        Author URI: http://your-domain.com
        Text Domain: englishonlyadmin
        */
        function weplugins_modify_locale_defaults($locale) { 
            // Force English
            return 'en_US'; 
        }
        // Add the filter
        add_filter("locale", "weplugins_modify_locale_defaults", 10, 1);
        

Live Example 2: Conditional Locale Change

This example shows how to change the locale based on a specific condition.

        function weplugins_modify_locale_defaults($locale) { 
            // Example condition: if user is admin
            if (current_user_can('administrator')) {
                return 'fr_FR'; // Force French for admins
            }
            return $locale; 
        }
        // Add the filter
        add_filter("locale", "weplugins_modify_locale_defaults", 10, 1);
        

Live Example 3: Removing the Locale Filter

This example demonstrates how to remove the locale filter if it’s no longer needed.

        // Assume the function weplugins_modify_locale_defaults() is already defined
        // Remove the filter
        remove_filter("locale", "weplugins_modify_locale_defaults", 10, 1);
        

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

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