How to get return POST API in Flutter

Question

I need your help. I've been follow tutorial for POST API from Login App using REST API and SQFLite , but I can't have any return after calling the request. Please correct my code below.

login_presenter.dart

doLogin(String username, String password) {
api.callAPI(username, password).then((Post user) {
  _view.onLoginSuccess(user);
}).catchError((Exception error) => _view.onLoginError(error.toString()));}

rest_ds.dart

Future<User> login(String username, String password) {
return _netUtil.post(LOGIN_URL, body: {
  "username": username,
  "password": password
}).then((dynamic res) {
  print(res.toString());
  if(res["error"]) throw new Exception(res["error_msg"]);
  return new User.map(res["user"]);
});

}

second tutorial I'd get from ParsingJSON-Flutter , the error Object.noSuchMethod always point at _presenter.doLogin(_username, _password); which mean I don't reach the presenter? Thanks for helping.

Solution

you should parse the JSON from response.body not the body directly.

Future<User> login(String username, String password) {
return _netUtil.post(LOGIN_URL, body: {
  "username": username,
  "password": password
}).then((response) {
      //check response status, if response status OK
      print("Response Status : $res");
      if(response.statusCode == 200){
        var data = json.decode(response.body);

        if(data.length>0){
          //Convert your JSON to Model here
        }
        else{
          //Get Your ERROR message's here
          var errorMessage = data["error_msg"];
        }
      }
});

Comments

[Zanshin]

please add some context to your answer