Global ajax handling skeleton

ajaxSetup.js

(function (App) {
  
    /**
     * Do before each Ajax request
     * ---------------------------
     *
     * 1. Disable ajax related DOM controls to prevent double submissions
     * 2. Extend each XHR object with a couple of methods that let ajax calls skip global handlers on-demand.
     *
     */
    $(document).ajaxSend(function (event, xhr, settings) {
      xhr.skipGlobalHandlers = function () {
        xhr._skipGlobalHandlers = true;
      };

      xhr.shouldSkipGlobalHandlers = function () {
        return xhr._skipGlobalHandlers === true;
      };

      if (App.session.id) {
        xhr.setRequestHeader("X-User-Id", App.session.id);
      }

      try {
        // do other stuff
      } catch (e) {
        return false;
      }
    });

    /**
     * After each ajax request
     * -----------------------
     * 
     */
    $(document).ajaxComplete(function (event, xhr, settings) {
        
    });


    function handleSessionTimeout () {
      App.showModal(new App.shared.views.SessionTimeout());
    }

    function handleAccountDeactivation () {
      App.showModal(new App.shared.views.AccountDeactivation({ message: message }));
    }

    /**
     * Global ajax error handler
     * -------------------------
     * 
     * Individual ajax calls can skip global handling either
     * using global: false option beforehand, or dynamically after receiving the response
     * by calling #skipGlobalHandlers on the XHR object.
     * 
     */
    $(document).ajaxError(function (event, xhr, ajaxSettings, thrownError) {
        if (xhr.shouldSkipGlobalHandlers() || _.contains(["abort"], (thrownError || "").toLowerCase())) {
            return;
        }

        switch (xhr.status) {
        case 401: // unauthenticated
            if (xhr.responseText.search('deactivated') > -1) {
                App._handleAccountDeactivation(xhr.responseText);
            }
            else {
                App._handleSessionTimeout();
            }
            break;
        case 403: // forbidden
            feedback.warn("You are not authorized to perform the requested operation.");
            break;
        case 422: // validation errors
            break;
        case 409:
            feedback.error(xhr.responseJSON.error);
            break;
        case 427: // stale or invalid csrf token, same user
            feedback.error("This operation was not available at this time. Please try again.");
            utils.acquireCSRFToken();
            break;
        case 428: // stale or invalid csrf token, other user
            location.href = "/";
            break;
        default:
            feedback.error("We could not perform your request at this time due to an unexpected error.");
        }
    });
  
}(MyApp));