feat: added ajax error handler

cms/templates/container_editor.html

@@ -175,6 +175,10 @@
                             // Serves to initialize the rendering of a xblock edit modal window.
                             setTimeout(() => $('.button-edit').trigger('click'), 300);
 
+                            const iframeMessageHandler = (method, msg) => {
+                                return window.parent.postMessage({ method, msg }, '*');
+                            }
+
                             /**
                              * Callback function for the MutationObserver to handle mutations
                              * and send information when the modal window close logic is triggered.
@@ -195,7 +199,7 @@
 
                                 // If removed nodes match the current modal, post a message to close the edit modal.
                                 if (editModalRemovedNodes.length > 0) {
-                                    window.parent.postMessage({ method: 'close_edit_modal', msg: 'Message from edit iframe modal' }, '*');
+                                    iframeMessageHandler('close_edit_modal', 'Sends a message when the modal window is closed');
                                 }
                             })
 
@@ -205,6 +209,20 @@
                                 attributes: true,
                                 attributeFilter: ['class']
                             });
+
+                            const originalAjax = $.ajax;
+                            // Notifies the parent element that a server error has occurred.
+                            $.ajax = function(options) {
+                                const errorHandler = options.error;
+                                options.error = function(xhr, textStatus, errorThrown) {
+                                    iframeMessageHandler('edit_modal-error', 'Sends a message in case of server error');
+
+                                    if (errorHandler) {
+                                        errorHandler(xhr, textStatus, errorThrown);
+                                    }
+                                };
+                                return originalAjax.call(this, options);
+                            };
                         });
                     </script>
                 </%block>