javascript - AngularJS Bypass promise if data is present in cache -

i sending ajax request fetch data server , storing in local variable. inside service. in controller using promise data when needed. first time works because no cache detected , promise returned next time onwards not returning promise service function , hence javascript error.

my function in service is:

    getproductdetails: function(product) {         if(!productdetailsarr[product.id]) {             if (!promiseproductdetails) {                 // $http returns promise, has function, returns promise                 promiseproductdetails = $http.get(product.id + '/productdetails.json').then(function(response) {                     productdetailsarr[product.id] = response;                     return productdetailsarr[product.id];                 });             }             // return promise controller             return promiseproductdetails;         } else {             return productdetailsarr[product.id];         }      } 

in controller have invoked above function following code:

servicedata.getproductdetails($scope.product).then(function(data) {     $scope.productdetails = data; }); 

so on second time onwards js error:

typeerror: servicedata.getproductdetails(...).then not function 

any idea how fix this.

what should doing returning promise. in case, can return resolved promise. can read more here.

    if(!productdetailsarr[product.id]) {         if (!promiseproductdetails) {             // $http returns promise, has function, returns promise             promiseproductdetails = $http.get(product.id + '/productdetails.json').then(function(response) {                 productdetailsarr[product.id] = response;                 return productdetailsarr[product.id];             });         }         // return promise controller         return promiseproductdetails;     } else {         var deferred = $q.defer();         deferred.resolve(productdetailsarr[product.id]);         return deferred.promise;     }