Implementing loading spinner using httpInterceptor and AngularJS 1.1.5

I've found an example of a loading spinner for http/resource calls here on SO:

• Set rootScope variable on httpIntercept (Plunker: http://plnkr.co/edit/32Mh9UOS3Z4vnOtrH9aR?p=preview)

As you can see the implementation works (using AngularJS 1.0.5). However if you change the sources to AngularJS 1.1.5. The example does not work anymore.

I learned that $httpProvider.responseInterceptors is deprecated in 1.1.5. Instead one should use $httpProvider.interceptors

Unfortunately just replacing the above string in the Plunker did not solve the problem. Has anyone ever done such a loading spinner using HttpInterceptor in AngularJS 1.1.5?

Thanks for your help!

Michael

Solution 1:

Thanks to Steve's hint I was able to implement the loader:

Interceptor:

.factory('httpInterceptor', function ($q, $rootScope, $log) {

    var numLoadings = 0;

    return {
        request: function (config) {

            numLoadings++;

            // Show loader
            $rootScope.$broadcast("loader_show");
            return config || $q.when(config)

        },
        response: function (response) {

            if ((--numLoadings) === 0) {
                // Hide loader
                $rootScope.$broadcast("loader_hide");
            }

            return response || $q.when(response);

        },
        responseError: function (response) {

            if (!(--numLoadings)) {
                // Hide loader
                $rootScope.$broadcast("loader_hide");
            }

            return $q.reject(response);
        }
    };
})
.config(function ($httpProvider) {
    $httpProvider.interceptors.push('httpInterceptor');
});

Directive:

.directive("loader", function ($rootScope) {
    return function ($scope, element, attrs) {
        $scope.$on("loader_show", function () {
            return element.show();
        });
        return $scope.$on("loader_hide", function () {
            return element.hide();
        });
    };
}
)

CSS:

#loaderDiv {
   position: fixed;
   top: 0;
   right: 0;
   bottom: 0;
   left: 0;
   z-index: 1100;
   background-color: white;
   opacity: .6;
}

.ajax-loader {
   position: absolute;
   left: 50%;
   top: 50%;
   margin-left: -32px; /* -1 * image width / 2 */
   margin-top: -32px; /* -1 * image height / 2 */
   display: block;
}

HTML:

<div id="loaderDiv" loader>
    <img src="src/assets/img/ajax_loader.gif" class="ajax-loader"/>
</div>

Solution 2:

"responseInterceptors" was deprecated. "interceptors" replaced it with many enhancements in a preview version. Off the top of my head I don't remember which version. Documentation on this is sparse, so you're probably best off examining the source code.

The gist of the change looks like this:

$httpProvider.interceptors.push(function($q, $rootScope) {
  return {
     'request': function(config) {
        // intercepts the request
     },
     'response': function(response) {
       // intercepts the response. you can examine things like status codes
     },
     'responseError': function(response) {
       // intercepts the response when the response was an error
     }
  }
});

In the angular source you will find documentation under "* # Interceptors" in the $HttpProvider function. There is an example usage very similar to what I posted above.

Solution 3:

The provided/accepted solution is fine IF you want to include JQuery in your solution, which the AngularJS team is recommending against going forward. element.show/.hide are not supported in Angular's JQLite.... So the following refactors are necessary to run in an non-jquery session:

Change the HTML element to add a class of 'hidden'

<div id="loaderDiv" loader class="hidden">
     <img src="Content/images/yourgif.gif" class="ajax-loader" />
</div>

Add the hidden class to your css:

.hidden{display:none !important}

And tweak the directive thus:

(function() {
    'use strict';

    angular
        .module('your_app')
        .directive('yourSpinner', yourSpinner);

    yourSpinner.$inject = ['$rootScope'];

    function yourSpinner($rootScope) {
       return function($scope, element, attrs) {
           $scope.$on("loader_show", function () {
               if (element.hasClass("hidden")) {
                   element.removeClass("hidden")
               }
            });
            return $scope.$on("loader_hide", function () {
                if(!element.hasClass("hidden")){
                    element.addClass("hidden")
                }
            });
        }
    }

})();

The factory is fine as-is.