Flutter Graphql basic query example

main.dart

import 'package:flutter/material.dart';
import 'package:graphql_flutter/graphql_flutter.dart';

void main() {
  WidgetsFlutterBinding.ensureInitialized();
  final HttpLink httpLink = HttpLink(
    uri: 'https://countries.trevorblades.com/',
  );
  final ValueNotifier<GraphQLClient> client = ValueNotifier<GraphQLClient>(
    GraphQLClient(
      link: httpLink,
      cache: OptimisticCache(dataIdFromObject: typenameDataIdFromObject),
    ),
  );

  runApp(
    MaterialApp(
      home: GraphQLProvider(
        client: client,
        child: MyApp(),
      ),
    ),
  );
}

class MyApp extends StatefulWidget {
  const MyApp();

  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Query(
            options: QueryOptions(
              documentNode: gql(r"""
                query{
                    continents{
                      name
                }"""),
            ),
            builder: (
              QueryResult result, {
              VoidCallback refetch,
              FetchMore fetchMore,
            }) {
              if (result.hasException) {
                return Text(result.exception.toString());
              }
              if (result.loading) {
                return Center(child: CircularProgressIndicator());
              }
              print(result.data);
              return ListView.builder(
                itemBuilder: (context, index) => Text("${result.data}"),
              );
            }),
      ),
    );
  }
}