How the ChildActionOnly Methods of the controller in plugins are loaded inside the Nop.Web Views?

How the Nop.Plugin.Payments.AuthorizeNet View PaymentInfo.cshtml is loading inside the following div in OnePageCheckout.cshtml?

<div id="checkout-payment-info-load">
                        @*payment info content will be loaded here*@ Payment is not required
</div>

partial view of paymentinfo is requested from the payment gateway plugin by the payment workflow ( onepage checkout or multiple page checkout) and inserted in the view.

http://www.elaamart.com

arlen_bs wrote:

By mean of AJAX. :)

\Nop.Web\Scripts\public.onepagecheckout.js

The following section loads the html content of partial view inside the appropriate div tag.

setStepResponse: function (response) {
        if (response.update_section) {
            $('#checkout-' + response.update_section.name + '-load').html(response.update_section.html);
        }
        if (response.allow_sections) {
            response.allow_sections.each(function (e) {
                $('#opc-' + e).addClass('allow');
            });
        }