How to use pre_user_login filter in WordPress

pre_user_login filter

This filter is called before the user is created or updated.

To use the pre_user_login filter, first, you have to register it using add_filter. 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 modify_pre_user_login_defaults which takes 1 parameter and we registered using add_filter. The first parameter pre_user_login is the name of the hook, the second parameter modify_pre_user_login_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.

Sometimes, you have to remove a registered hook, so you can use remove_filter to remove pre_user_login filter.

Parameters

• $sanitized_user_login : (string) Username after it has been sanitized.

Live Example

Example 1: Check if the User has been Created

Below is an example of how you can check if the user has been created.

    /**
     * Check if the user has been created.
     *
     * @param string $login User login.
     * @return string (Maybe) filtered login.
     */
    function weplugins_check_if_user_created( $login ) {
        // Don't do anything to login, just see if already in database.
        global $wpdb, $is_new_login;
        $is_new_login = $wpdb->get_var( $wpdb->prepare( "SELECT user_login FROM $wpdb->users WHERE user_login = '%s'", $login ) );
        return $login;
    }
    add_filter( 'pre_user_login', 'weplugins_check_if_user_created', 10, 1 );
    

Example 2: Modify User Login

Below is an example of how you can use this hook to modify the user login.

    function weplugins_modify_pre_user_login_defaults($sanitized_user_login) { 
        // Update the $sanitized_user_login variable according to your website requirements and return this variable.
        // You can modify the $sanitized_user_login variable conditionally too if you want.
        return $sanitized_user_login; 
    }
    // add the filter
    add_filter( "pre_user_login", "weplugins_modify_pre_user_login_defaults", 10, 1 );
    

Example 3: Remove a Hook Callback

To remove a hook callback, use the example below.

    remove_filter( "pre_user_login", "weplugins_modify_pre_user_login_defaults", 10, 1 );
    

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