How to check if checkout guest form is submited?

Hi,

You can do that with javascript.
In the different show_block_ files of the "checkout" view, near the end, you have some javascript called when actions are made.
So you would have by default some CSS, and then, in the javascript of the show_block_login, you would have some custom javascript to change that CSS dynamically.
For example, in the submitLogin function, you can add your javascript for when someone click on the login / register / next button of the login view.

Hi,

In any PHP file on your website, if you want to know if a user is logged in to a joomla user account or not, you can use this code:
$user = JFactory::getUser();
if($user->guest) {
// not logged in
}

Similarily, in any PHP where HikaShop has been loaded before, you can use such code to know whether or not the user is connected to a HikaShop customer:
$hkuser = hikashop_loadUser();
if($hkuser) {
// connected as a guest or a user account
}
so then you can just mix both to know the exact situation of the customer in any view file of HikaShop.

With window.Oby.registerAjax you can register functions to be run when something changes. But that's different from "when something is submitted". In that case, you should rather change the submitLogin function as I was saying previously and from there, directly trigger the refresh of the shipping view (with a delay using the setTimeout function of js).