cacheing promises in angularJS so requests don't pile up

cached-promise.js

angular.module('configModule')

.factory('timezoneService', ['configApiService', '$q',
    function(configApiService, $q) {
        var tzPromise = false;

        var service = {
            get: getTz,
        };

        return service;

        ////////////////////////

        function getTz() {

            if (!tzPromise){
                var config = { path: 'general.store.timezone' };

                tzPromise = configApiService.getPath(config).$promise
                    .then(function(response) {
                        return response.result.substr(3);
                    });
            }

            return tzPromise;
        }
      }
    }
]);