flutter dart error when installing google api calendar

0
votes

I will display a list of events from Google Calendar. I followed the example already in the following link : How to use Google API in flutter?

and my script is as follows :

import 'package:http/http.dart' as http;

assumed I was logged in.

GoogleSignIn _googleSignIn = GoogleSignIn(
  scopes: <String>[
    'email',
    'https://www.googleapis.com/auth/contacts.readonly',
    'https://www.googleapis.com/auth/calendar'
  ],
);'

class GoogleHttpClient extends http.BaseClient {
  Map<String, String> _headers;

  GoogleHttpClient(this._headers) : super();

  @override
  Future<http.StreamedResponse> send(http.BaseRequest request) =>
      super.send(request..headers.addAll(_headers)); //have error 'the method 'send' is always abstract in the supertype'

  @override
  Future<http.Response> head(Object url, {Map<String, String> headers}) =>
      super.head(url, headers: headers..addAll(_headers));
}

void getCalendarEvents() async {
    final authHeaders = _googleSignIn.currentUser.authHeaders;
    final httpClient = new GoogleHttpClient(authHeaders); //have error "The argument type 'Future<Map<String, String>>' can't be assigned to the parameter type 'Map<String, String>'"
    var calendar = new Calendar.CalendarApi(new http.Client());
    var calEvents = calendar.events.list("primary");
    calEvents.then((Calendar.Events events) {
      events.items.forEach((Calendar.Event event) {print(event.summary);});
    });
}

the above script cannot run because of an error.

the method 'send' is always abstract in the supertype

can someone help me?

3
dartflutter

3 Answers

1
votes

If your code is based on How to use Google API in flutter? you'll see that I have a @override Future<StreamedResponse> send(...) in my code.

GoogleHttpClient extends abstract class IOClient that is missing an implementation of send, so the concrete subclass needs to implement it.

That's what the error message is about.

1
votes

Replace StreamedResponse with IOStreamedResponse add IOClient library replace class GoogleHttpClient extends IOClient with class GoogleHttpClient extends http.BaseClient

0
votes

1 This is error

//have error "The argument type 'Future<Map<String, String>>' can't be assigned to the parameter type 'Map<String, String>'"

fixed: add await ahead

Like below: 

final authHeaders = await _googleSignIn.currentUser.authHeaders;

2: Change like below

var calendar = new Calendar.CalendarApi(new http.Client());

to

var calendar = new Calendar.CalendarApi(httpClient);

======> Final:

void getCalendarEvents() async {
final authHeaders = await _googleSignIn.currentUser.authHeaders;
final httpClient = new GoogleHttpClient(authHeaders);
var calendar = new Calendar.CalendarApi(httpClient);
var calEvents = calendar.events.list("primary");
calEvents.then((Calendar.Events events) {
  events.items.forEach((Calendar.Event event) {print(event.summary);});
});
}

It worked for me.