You need to return a promise even if you return the cached data.

So define your deferred at the top of the code then to return the cached data:

if (angular.isObject(metaData)) {
      deferred.resolve(metaData);
     return deferred.promise;
}

This way you get the same data back regardless of whether the data was returned from the AJAX call or from the cached data.

You might want to read this:
http://weblog.west-wind.com/posts/2014/Oct/24/AngularJs-and-Promises-with-the-http-Service

which explains some of the mechanics behind this...

+++ Rick ---
>


Define your $q.defer() before the first call then deferred.resolve(metaData); return deferred.promise() with the cached data and return the promise in the if block.

+++ Rick ---

>Hi everybody,
>
>I have two pages in the same form that need to access the same data.
>
>Each of the pages is controlled by its own controller and both have this code in the init:
>
>

>invoicesService.getMetaData().then(function (data) {
>                        $scope.invoicesMetaData = data;
>
>                    });

>
>So, I want to somehow adjust the service code to not invoke the method twice. Here is what I attempted to do but it's not working:
>
>

>app.factory('invoicesService', ['$http', '$q', function($http, $q) {
>
>        var metaData = null;
>
>        var getMetaData = function () {
>            if (angular.isObject(metaData))
>                return metaData;
>
>            var deferred = $q.defer();
>            $http.get('/api/invoices/metadata')
>                .success(function (data) {
>                    metaData = data;
>                    deferred.resolve(data);
>                    
>                })
>                .error(function (data, status, header, config) {
>                    deferred.reject(status);
>                });
>            return deferred.promise;
>        };

>
>I still get 2 hits in my API controller. Do you see how should I change the above to avoid the second call after the first one was already made?
>
>Thanks in advance.