How to add Dynamic HTTP headers in Flutter Network Calls

Question

I have to get 'cookie' header from Login API response and use that in other API's.

I am able to get header value from http.Response

Like this

var cookie = loginResponsehttp.headers.keys.firstWhere(
    (k) => loginResponsehttp.headers[k] == 'cookie',
    orElse: () => null);

But Now I want to dynamically add this header value in future API calls. (API calls which will be after login)

Solution

Just create an API class with a custom method to do the requests and store the cookie in the class.

bare bones implementation (adapted from working code, things removed and simplified):

class MyApi {

  String myCookie;

  Future<bool> loginUser({@required String username, @required String password}) {

    // THIS must be the return point, because we are returning a future!!!
    return this.apiRequest(method: 'post', url: 'http://example.com/api/login', params: {'user': username, 'password':password})
    .then( (response) {
        if (response.statusCode == 200) {

            // GET THE COOKIE HERE
            myCookie = response.headers.keys.firstWhere((k) => loginResponsehttp.headers[k] == 'cookie', orElse: () => null);
        }
    }

  Future<http.Response> apiRequest({
    @required String url,
    dynamic params}) async {

      // separate in to get an all
      if(method == 'get') {
        return http.get(url, headers: {'X-Auth': myCookie, 'Content-Type': 'application/json'});
      } else if (method == 'post') {
        return http.post(url, body: json.encode(params), headers: {'X-Auth': myCookie, "Content-Type": 'application/json'});
      } else {
        // ERROR!!! throw exception?
        throw Exception('Unknown http method: ' + method);
      }
    }
 }

Comments

[Developine]

Brother this is not a good solution, saving cookie value in a variable and using in the next request. I can do that easily, any elegant solution?