Show spinner GIF during an $http request in AngularJS?

Question

This really depends on your specific use case, but a simple way would follow a pattern like this:

.controller('MainCtrl', function ( $scope, myService ) {
  $scope.loading = true;
  myService.get().then( function ( response ) {
    $scope.items = response.data;
  }, function ( response ) {
    // TODO: handle the error somehow
  }).finally(function() {
    // called no matter success or failure
    $scope.loading = false;
  });
});

And then react to it in your template:

<div class="spinner" ng-show="loading"></div>
<div ng-repeat="item in items>{{item.name}}</div>

Here are the current past AngularJS incantations:

angular.module('SharedServices', [])
    .config(function ($httpProvider) {
        $httpProvider.responseInterceptors.push('myHttpInterceptor');
        var spinnerFunction = function (data, headersGetter) {
            // todo start the spinner here
            //alert('start spinner');
            $('#mydiv').show();
            return data;
        };
        $httpProvider.defaults.transformRequest.push(spinnerFunction);
    })
// register the interceptor as a service, intercepts ALL angular ajax http calls
    .factory('myHttpInterceptor', function ($q, $window) {
        return function (promise) {
            return promise.then(function (response) {
                // do something on success
                // todo hide the spinner
                //alert('stop spinner');
                $('#mydiv').hide();
                return response;

            }, function (response) {
                // do something on error
                // todo hide the spinner
                //alert('stop spinner');
                $('#mydiv').hide();
                return $q.reject(response);
            });
        };
    });

//regular angular initialization continued below....
angular.module('myApp', [ 'myApp.directives', 'SharedServices']).
//.......

Here is the rest of it (HTML / CSS)....using

$('#mydiv').show(); 
$('#mydiv').hide(); 

to toggle it. NOTE: the above is used in the angular module at beginning of post

#mydiv {  
    position:absolute;
    top:0;
    left:0;
    width:100%;
    height:100%;
    z-index:1000;
    background-color:grey;
    opacity: .8;
 }

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

<div id="mydiv">
    <img src="lib/jQuery/images/ajax-loader.gif" class="ajax-loader"/>
</div>

Here's a version using a directive and ng-hide.

This will show the loader during all calls via angular's $http service.

In the template:

<div class="loader" data-loading></div>

directive:

angular.module('app')
  .directive('loading', ['$http', function ($http) {
    return {
      restrict: 'A',
      link: function (scope, element, attrs) {
        scope.isLoading = function () {
          return $http.pendingRequests.length > 0;
        };
        scope.$watch(scope.isLoading, function (value) {
          if (value) {
            element.removeClass('ng-hide');
          } else {
            element.addClass('ng-hide');
          }
        });
      }
    };
}]);

by using the ng-hide class on the element, you can avoid jquery.

---

Customize: add an interceptor

If you create a loading-interceptor, you can show/hide the loader based on a condition.

directive:

var loadingDirective = function ($rootScope) {
  return function ($scope, element, attrs) {
      $scope.$on("loader_show", function () {
          return element.removeClass('ng-hide');
      });
      return $scope.$on("loader_hide", function () {
          return element.addClass('ng-hide');
      });
  };
};

interceptor:

• for example: don't show spinner when response.background === true;
• Intercept request and/or response to set $rootScope.$broadcast("loader_show"); or $rootScope.$broadcast("loader_hide");

more info on writing an interceptor

If you are using ngResource, the $resolved attribute of an object is useful for loaders:

For a resource as follows:

var User = $resource('/user/:id', {id:'@id'});
var user = User.get({id: 1})

You can link a loader to the $resolved attribute of the resource object:

<div ng-hide="user.$resolved">Loading ...</div>