AngularJS: Resolve in RouteProvider - detecting Success / Failure?

If the resolve function fail, you will probably want to display to the user something accordingly (like an error message). It would be better to let your resolve function return a promise (without then) and use the internal event $routeChangeError.

myApp.run(['$rootScope',function($rootScope) {
  $rootScope.$on('$routeChangeError', function() {
    // what you want to do if an error occurs 
    // ex: $rootScope.displayErrorMessage = true
  });

])

It will also be easier to deal with generic error (like network error / server down etc).

You can just return the return value of the then method:

resolve: {
    resolvedData: function(Restangular){
        return Restangular.one('Items').get().then(function (data) {
            ...
            return successData; // resolvedData will be resolved with the successData
            }, function () {
            ...
            return failureData; // resolvedData will be resolved with the failureData
            });
    }
}

The then method doc:

This method returns a new promise which is resolved or rejected via the return value of the successCallback or errorCallback.