Register to aqueduct backend from Flutter frontend - flutter

Question

I'm having a bit of difficulty with registering to aqueduct backend from my Flutter frontend
Here is my code in my frontend:
Future<void> signUp(String email, String password) async {
final body = "username:$email,password:$password"; //<- return request entity could not be decoded
//final body = {"username": email, "password": password}; //<- return bad state: Cannot set the body fields of Request with content-type "application/json"
try {
final http.Response response = await http.post(
"http://localhost:8888/register",
headers: {"Content-Type": "application/json"},
body: body);
final jsonResponse = json.decode(response.body);
if (jsonResponse["error"] != null) {
throw HttpException(jsonResponse["error"]);
}
} catch (error) {
throw error;
}
}
There must be some silly mistake. I believe it is with formatting body so I tried 2 options and both throw different http exception (as in comment).

Answer 1

Here is an example of connecting to an Aqueduct server from a Flutter client. (This isn't really a server question, though, since the client and server are independent of each other.)
Here is an example of registering:
void _register(String email, String password) async {
Map<String, String> headers = {"Content-type": "application/json"};
final jsonString = '{"username":"$email", "password":"$password"}';
Response response = await post(YOUR_URL_HERE, headers: headers, body: jsonString);
print('${response.statusCode} ${response.body}');
}
In your example you aren't encoding the JSON correctly.
And here is another example of signing in. The class is a view model architecture that I talk about here.
import 'dart:convert';
import 'package:flutter/foundation.dart';
import 'package:http/http.dart' as http;
class LoginViewModel extends ChangeNotifier {
String _token = '';
bool _isLoggedIn = false;
bool get isLoggedIn => _isLoggedIn;
String get token => _token;
Future onLoginPressed(String username, String password) async {
if (username.isEmpty || password.isEmpty) {
return;
}
_isLoggedIn = await _login(username, password);
notifyListeners();
}
Future<bool> _login(String username, String password) async {
var clientID = 'com.example.app';
var clientSecret = '';
var body = 'username=$username&password=$password&grant_type=password';
var clientCredentials = Base64Encoder().convert('$clientID:$clientSecret'.codeUnits);
Map<String, String> headers = {
'Content-type': 'application/x-www-form-urlencoded',
'authorization': 'Basic $clientCredentials'
};
var response = await http.post(YOUR_URL_HERE, headers: headers, body: body);
final responseBody = response.body;
if (response.statusCode != 200) {
return false;
}
final map = json.decode(responseBody);
_token = map['access_token'];
return true;
}
}