When changing quantities, be sure to return the new CyberSource submit form…

When changing quantities, be sure to return the new CyberSource submit form html. Also, to ensure that any browser content is fully refreshed when clicking the back button, force a page refresh to reset client state

lms/djangoapps/shoppingcart/views.py

@@ -138,7 +138,19 @@ def update_user_cart(request):
         old_to_new_id_map = item.order.update_order_type()
         total_cost = item.order.total_cost
 
-        return JsonResponse({"total_cost": total_cost, "oldToNewIdMap": old_to_new_id_map}, 200)
+        callback_url = request.build_absolute_uri(
+            reverse("shoppingcart.views.postpay_callback")
+        )
+        cart = Order.get_cart_for_user(request.user)
+        form_html = render_purchase_form_html(cart, callback_url=callback_url)
+
+        return JsonResponse(
+            {
+                "total_cost": total_cost,
+                "oldToNewIdMap": old_to_new_id_map,
+                "form_html": form_html,
+            }
+        )
 
     return HttpResponseBadRequest('Order item not found in request.')
 

lms/templates/shoppingcart/shopping_cart.html

@@ -9,6 +9,7 @@ from django.utils.translation import ugettext as _
 
 %>
 
+
 <%block name="custom_content">
 
 <div class="container">
@@ -108,7 +109,9 @@ from django.utils.translation import ugettext as _
                     </p>
               </div>
                <div name="payment" class="hidden">
-                ${form_html}
+                <div id="processor_form">
+                  ${form_html}
+                </div>
                 <p>
                     ${_('After this purchase is complete,')}<br/><b>${order.user.username}</b>
                     ${_('will be enrolled in this course.')}
@@ -141,14 +144,32 @@ from django.utils.translation import ugettext as _
         <a href="${marketing_link('COURSES')}" class="blue">${_('View Courses')}</a>
       </div>
     % endif
-
 </div>
+<form id='refresh_tracker'>
+   <input id="reloadValue" type="hidden" name="reloadValue" value="" />
+</form>
 </%block>
 <script>
     $(function() {
         var isSpinnerBtnEnabled = true;
         var prevQty = 0;
 
+        // This snipnet of code is to detect when and
+        // end-user has clicked the back button to the
+        // page. We want to force refresh to make
+        // sure there is no cached data happening
+        var d = new Date();
+        d = d.getTime();
+        if (jQuery('#reloadValue').val().length == 0)
+        {
+          jQuery('#reloadValue').val(d);
+        } else
+        {
+          jQuery('body').hide();
+          jQuery('#reloadValue').val('');
+          location.reload(true);
+        }
+
       $('a.btn-remove').click(function(event) {
       event.preventDefault();
       var post_url = "${reverse('shoppingcart.views.remove_item')}";
@@ -317,6 +338,7 @@ from django.utils.translation import ugettext as _
                   var prevTotal = data['total_cost'];
                   $('html').css({'cursor':'default'});
                   $(".button").css({'cursor':'default'});
+                  $("#processor_form").html(data['form_html']);
                   if(typeChanged){
                       var submit_button = $('.col-2.relative').find("input[type='submit']")
                       submit_button.removeAttr('disabled');
@@ -410,4 +432,5 @@ from django.utils.translation import ugettext as _
 
 	});
 });
+
 </script>