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

class HogeApp extends StatelessWidget {

  @override
  Widget build(BuildContext context) {
    // <1> Use FutureBuilder
    return FutureBuilder(
        // <2> Pass `Future` to future
        future: FirebaseFirestore.instance.collection('posts').get(),
        builder: (context, snapshot) {
          if (snapshot.hasData) {
            // <3> Retrieve `List` from snapshot
            final List documents = snapshot.data.docs;
            return ListView(
                children: documents
                    .map((doc) => Card(
                          child: ListTile(
                            title: Text(doc['text']),
                            subtitle: Text(doc['email']),
                          ),
                        ))
                    .toList());
          } else if (snapshot.hasError) {
            return Text('It's Error!');
          }
        });
  }
}