angularjs - How to handle Restangular .getList() response that's not an array -

the api i'm working returns 200 string error message when client isn't authenticated. if call:

var restsvc = restangular.service('message'); var deferred = restsvc.getlist() 

when authenticated array of objects -- if call when not authenticated string "the caller not authenticated."

the problem i'm not able handle error because restangular throws error , doesn't resolve or fail deferred because it's expecting array:

error: response getlist should array , not object or else 

how can handle error , response if it's not array?

one thing can add response interceptor test data before returned. if conforms specific format attach response data. example.

restangularconfig.addresponseinterceptor(function(response, operation) {     if (operation === 'getlist') {         // test data structure here.     }     return response; }); 

if own api designing highly recommend changing format consistent every request. example.

if request good.

{   "status": 200,   "content": [{},{}...]   } 

if request bad.

{   "status": 401, //or ever error   "content": [] }