如何使用graphql从Firebase中使用flutter获取云Firestore数据？

dependencies:
  graphql_flutter: ^4.0.0

import 'package:graphql_flutter/graphql_flutter.dart';

void main() {
  final HttpLink httpLink = HttpLink(
    uri: 'https://your-firebase-project-url.com/graphql',
  );

  final ValueNotifier<GraphQLClient> client = ValueNotifier<GraphQLClient>(
    GraphQLClient(
      link: httpLink,
      cache: GraphQLCache(),
    ),
  );

  runApp(MyApp(client: client));
}

class MyApp extends StatelessWidget {
  final ValueNotifier<GraphQLClient> client;

  const MyApp({Key? key, required this.client}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return GraphQLProvider(
      client: client,
      child: MaterialApp(
        title: 'Flutter GraphQL Demo',
        home: MyHomePage(),
      ),
    );
  }
}

import 'package:graphql_flutter/graphql_flutter.dart';

final String getFirestoreDataQuery = '''
  query GetFirestoreData {
    collectionName {
      documentName {
        field1
        field2
      }
    }
  }
''';

import 'package:graphql_flutter/graphql_flutter.dart';

class MyHomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Flutter GraphQL Demo'),
      ),
      body: Query(
        options: QueryOptions(
          document: gql(getFirestoreDataQuery),
        ),
        builder: (QueryResult result, {VoidCallback? refetch}) {
          if (result.hasException) {
            return Text(result.exception.toString());
          }

          if (result.isLoading) {
            return CircularProgressIndicator();
          }

          final data = result.data!['collectionName']['documentName'];

          return ListView.builder(
            itemCount: data.length,
            itemBuilder: (context, index) {
              final item = data[index];

              return ListTile(
                title: Text(item['field1']),
                subtitle: Text(item['field2']),
              );
            },
          );
        },
      ),
    );
  }
}