Auto log in hook is requiring a page refresh

Question

I have a simple auto log in hook that looks like the following:

function auto_login() {
    if (!is_user_logged_in()) {
        //Removed some code for brevity.

        $user = get_userdatabylogin($domainName);

        if ($user != null) {
            //Set the auth cookie.
            wp_set_auth_cookie($user->ID, false, null);
            //Set the current user (this will also set WP objects at the global level)
            wp_set_current_user($user->ID);
        }
    }
}
add_action('init', 'auto_login');

This code does work, but, in order to get the admin bar at the top of the page it requires a page refresh. This makes me think that I'm not getting some global objects populated early enough in the Wordpress page life cycle.

Should I be calling this method somewhere else besides init?

Answer 1

Maybe it is too late to hook on init. Try set_current_user or some earlier hook. List is here: https://codex.wordpress.org/Plugin_API/Action_Reference

Answer 2

I've found that the user can be automatically logged in on template_redirect and set successfully using wp_redirect('yoururl'), which, essentially, redirects back with the cookie instead of reloading the page.

Example:

function auto_login() {
    // if statements go here...

    $user_id = 'some_user_id';

    wp_set_auth_cookie($user_id);
    wp_set_current_user($user_id);

    wp_redirect(home_url());
    exit;
}
add_action('template_redirect', 'auto_login');