Get response header in then() function of a ngResource object's $promise property after resource resolved?

Question

I\'m willing to retrieve the response header of a resource request, cause I\'ve put pagination information and something else in it rather than the response body, to make the RE

Answer 1

We can't use .then for returning the header because the promise doesn't allow for multiple return values. (e.g., (res, err))

This was a requested feature, and was closed https://github.com/angular/angular.js/issues/11056

... the then "callbacks" can have only [one] argument. The reason for this is that those "callbacks" correspond to the return value / exception from synchronous programming and you can't return multiple results / throw multiple exceptions from a regular function.

Answer 2

I had the exact same problem. I used an interceptor in the resource definition to inject the http headers in the resource.

$resource('/api/resource/:id', {
    id: '@id'
  }, {
    index: {
      method: 'GET',
      isArray: true,
      interceptor: {
        response: function(response) {
          response.resource.$httpHeaders = response.headers;
          return response.resource;
        }
      }
    }});

Then, in the then callback, the http headers are accesible through $httpHeaders:

promise.then(function(resource) {
    resource.$httpHeaders('header-name');
});

Answer 3

I think I had a similar problem: After POSTing a new resource I needed to get the Location header of the response, since the Id of the new resource was set on the server and then returned via this header.

I solved this problem by introducing my own promise like this:

app.factory('Rating', ['$resource',
    function ($resource) {

        // Use the $resource service to declare a restful client -- restangular might be a better alternative
        var Rating = $resource('http://localhost:8080/courserater/rest/ratings-cors/:id', {id: '@id'}, {
            'update': { method: 'PUT'}
        });

    return Rating;
}]);

function RestController($scope, $q, Rating) {
  var rating = new Rating();
  var defer = $q.defer(); // introduce a promise that will be resolved in the success callback
  rating.$save(function(data, headers){ // perform a POST
      // The response of the POST contains the url of the newly created resource
      var newId = headers('Location').split('/').pop();
      defer.resolve(newId)
    });
    return defer.promise;
  })
  .then (function(newId) {
    // Load the newly created resource
    return Rating.get({id: newId}).$promise; // perform GET
  })
  .then(function(rating){
    // update the newly created resource
    rating.score = 55;
    return rating.$update(); // perform PUT
  });
}