access headers with ngResource - angularjs

Question

I have a Api in which retrieves a custom header: X-Total-Count : "total of items", I'm using angular with ngResource.
My factory look like this:
app.factory("shopFactory", function ($resource) {
return {
User: $resource("http://localhost:58495/users/api/User/?id=:id", { id: "#id" }),
Category: $resource("http://localhost:58495/category/:id", { id: "#id" }),
Product: $resource("http://localhost:58495/products/?from=:from&to=:to", { from: "#from", to: "#to" })
};
});
And when I call it:
var productServer = shopFactory.Product.query({ from: 0, to: 10 }).$promise.then(function (response) {
$scope.product = response;
console.log(response);
}, function (error) {
console.log("ERROR");
console.log(error);
});
How can I access my custom header through ngResource, I can access it but with $http, I want to do it with the $resource way, Thanks

Answer 1

The query action method can be called with three arguments:
Resource.query([parameters], [success], [error])
The success callback is called with (value (Object|Array), responseHeaders (Function), status (number), statusText (string)) arguments, where the value is the populated resource instance or collection object. The error callback is called with (httpResponse) argument.
var productServer = shopFactory.Product.query(
{ from: 0, to: 10 },
function success (value, headers, status, statusText) {
$scope.product = value;
console.log(value);
console.log(headers());
},
function error (error) {
console.log("ERROR");
console.log(error);
}
);
For more information, see AngularJS $resource Service API Reference.
whats the difference between using $promise.then and the success function,
The function in the .then method exposes only the value of the final response. While the success callback exposes four arguments: value (Object|Array), responseHeaders (Function), status (number), statusText (string).
The $promise can be passed as an argument to other functions and its .then method can be invoked multiple times.
Another very important difference is that the .then method creates a new promise from values returned.
Chaining promises
Because calling the .then method of a promise returns a new derived promise, it is easily possible to create a chain of promises.
It is possible to create chains of any length and since a promise can be resolved with another promise (which will defer its resolution further), it is possible to pause/defer resolution of the promises at any point in the chain. This makes it possible to implement powerful APIs.
— AngularJS $q Service API Reference (Chaining Promises)