angularjs - using angular $resource properly -

here code:

var dbdelivery = deliveries.get({deliveryid: delivery.id}, function() {                 if (!dbdelivery.id) {                     toaster.pop('error', 'error', 'that delivery not exist. else may have deleted it.');                     var deliveryindex = $rootscope._.findindex($scope.deliveries, 'id', delivery.id);                     $scope.deliveries.splice(deliveryindex, 1);                     return;                 }                 dbdelivery.confirmed = true;                 dbdelivery.$update(function() { delivery.confirmed = true; }, servererroralert);                 return dbdelivery.$promise;             }) 

questions: 1) happens if 1 calls multiple resource methods on resource , returns $promise? depend on last method executed? 2) $resource looking in order reject promise? mean depend on response status code? if status codes result in success , result in error?

1) can chain promises, every $resource method call generate new promise represent called method promise

2) resolve promise if http response code success code 2xx (see)