Flutter Dart: Error _ImmutableMap<dynamic, dynamic>' is not a subtype of type 'Map<String, dynamic>

Question

I have this code

import "./HTTPMethod.dart";
import '../../DataModel/DataModel.dart';
mixin RouterMixin {
  HTTPMethod method;
  String scheme;
  String path;
  String baseURL;
  Map<String, dynamic> params;
  Map<String, String> headers;
}
class Router with RouterMixin {
  HTTPMethod method;
  String scheme;
  String path;
  String baseURL;
  Map<String, dynamic> params;
  Map<String, String> headers;
  Router._(this.method, this.path, this.scheme, this.baseURL, this.params,
      this.headers);
  // ignore: missing_return
  static Router getRouter(method, path,
      {scheme = "https://",
      baseURL = "xyz.com",
      params = const {},
      headers = const {
        "Accept": "application/json",
        "Content-Type": "application/json"
      }}) {
    var headerValue = Map<String, dynamic>.from(headers);
    DataModel.shared.authToken.then((value) {
      print("TOKEN: $value");
      if (value != null) {
        headerValue["Authorization"] = value;
      }
      final router =
          Router._(method, path, scheme, baseURL, params, headerValue);
      return router;
    }).catchError((error) {
      print("ROUTER: ${error.toString()}");
    });
  }
}

It gives this error

flutter: type '_ImmutableMap<dynamic, dynamic>' is not a subtype of type 'Map<String, dynamic>'

Even i tried with simple

  static Router routerValue(method, path,
      {scheme = "https://",
      baseURL = "zyx.com",
      params = const {},
      headers = const {
        "Accept": "application/json",
        "Content-Type": "application/json"
      }}) {
    Router router = Router._(method, path, scheme, baseURL, params,
        {"Accept": "application/json", "Content-Type": "application/json"});
    return router;
    }

I gives same error.

Ali Qanbari · Accepted Answer · 2020-09-05 08:43:23Z

You need to change params default value from const {} to const <String, dynamic>{}. your getRouter function should return Future<Router> instead of Router because you need the value of authToken, otherwise your function won't return anything.

There are some other modification I made to your code which you can see here:

abstract class RouterBase {
  HTTPMethod method;
  String scheme;
  String path;
  String baseURL;
  Map<String, dynamic> params;
  Map<String, dynamic> headers; // change to dynamic
}

class Router implements RouterBase {
  HTTPMethod method;
  String scheme;
  String path;
  String baseURL;
  Map<String, dynamic> params;
  Map<String, dynamic> headers;

  Router._(this.method, this.path, this.scheme, this.baseURL, this.params,
      this.headers);

  static Future<Router> getRouter(
    method,
    path, {
    scheme = "https://",
    baseURL = "xyz.com",
    params = const <String, dynamic>{}, // add generic types to fix your problem
    headers = const {
      "Accept": "application/json",
      "Content-Type": "application/json"
    },
  }) async {
    Map<String, dynamic> headerValue = HashMap<String, dynamic>.from(headers);
    var authToken = await DataModel.shared.authToken;
    if (authToken != null) {
      headerValue["Authorization"] = authToken;
    }
    return Router._(method, path, scheme, baseURL, params, headerValue);
  }
}

Collectives™ on Stack Overflow

Flutter Dart: Error _ImmutableMap<dynamic, dynamic>' is not a subtype of type 'Map<String, dynamic>

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related