Flutter “this function has a return type of void and I want a return type of map”

Question

I am getting this error:This expression has a type of 'void' so its value can't be used. Try checking to see if you're using the correct API; there might be a function or call that returns void you didn't expect. Also check type parameters and variables which might also be void.

code:

import 'package:angel_framework/angel_framework.dart';
import 'package:angel_hot/angel_hot.dart';
import 'package:logging/logging.dart';
import 'dart:async';
import 'package:mongo_dart/mongo_dart.dart';

main() async {
  var hot = HotReloader(createServer, ['main.dart']);
  await hot.startServer('127.0.0.1', 3000);
}

Future<Angel> createServer() async {
  var app = Angel();
  app.logger = Logger('Log')..onRecord.listen((event) => print(event));
  print('start server..');

  Db db = Db('mongodb://localhost:27017/wearina');
  await db.open();
  print('connected to ${db.databaseName}');

  DbCollection userscoll = DbCollection(db, 'users');
  print('${userscoll.collectionName}');

app.post('/signup', (req, res) async {
    var body = await req.parseBody(); ////   parseBody => Future<void> , I want => Future<Map> ):
    var name = body['name'];
    var lastname = body['lastname'];
    var email = body['email'];
    var phone = body['phone'];
    var pass = body['pass'];
    });
  return app;
}

I don't understand what this is. I am new to flutter. This is my first app. Can someone please help me with this.

Solution

It seems that parseBody does not return a map of the pasred body. It just makes sure the body is parsed and you can access it from the req.bodyAsMap property. So your line should be:

 await req.parseBody();
 var body = req.bodyAsMap;

Comments

[Eli Front]

Check which line this error originates from. If need be you can add the full log to the question. I can help from there. This error is likely due to you to assigning a function to a variable/object, but because the function is void (doesn't return a value) there ends up being an error. This should be a quickfix, but I'll need to see the full code & error log.

[Mohammad Taghizadeh]

Thank you very much (: