How to use pre_get_main_site_id filter in WordPress

pre_get_main_site_id filter

Using the pre_get_main_site_id filter can feel a bit tricky at first, but once you get the hang of it, you’ll find it incredibly useful. This filter allows you to short-circuit the function by returning a positive integer.

To use the pre_get_main_site_id filter, you first need to register it using add_filter. You can place this code in the functions.php file of your active theme or in a custom WordPress plugin. At WePlugins, we always prefer creating a custom WordPress plugin for using hooks to ensure nothing breaks when updating your WordPress theme in the future.

In the live examples below, we’ve defined a function weplugins_modify_pre_get_main_site_id_defaults which takes two parameters. We registered it using add_filter. The first parameter pre_get_main_site_id is the name of the hook, the second parameter weplugins_modify_pre_get_main_site_id_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, and you can use remove_filter to remove the pre_get_main_site_id filter.

Parameters

Below are the two parameters required to use this hook:

• $main_site_id: (int|null) If a positive integer is returned, it is interpreted as the main site ID.
• $network: (WP_Network) The network object for which the main site was detected.

Live Example 1

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

    function weplugins_modify_pre_get_main_site_id_defaults($main_site_id, $network) { 
        // Update the $main_site_id variable according to your website requirements and return this variable. You can modify the $main_site_id variable conditionally too if you want.
        return $main_site_id; 
    }
    // add the filter
    add_filter( "pre_get_main_site_id", "weplugins_modify_pre_get_main_site_id_defaults", 10, 2 );
    

Live Example 2

To remove a hook callback, use the example below:

    remove_filter( "pre_get_main_site_id", "weplugins_modify_pre_get_main_site_id_defaults", 10, 2 );
    

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 example could be conditionally modifying the main site ID based on certain conditions:

    function weplugins_conditionally_modify_main_site_id($main_site_id, $network) {
        if ( /* some condition */ ) {
            $main_site_id = 2; // Example site ID
        }
        return $main_site_id;
    }
    add_filter( "pre_get_main_site_id", "weplugins_conditionally_modify_main_site_id", 10, 2 );
    

Contact Us

If you’re having any trouble using this hook or need customization, please contact us. We’re here to help!