FutureBuilder test

tab1.dart

import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
import 'dart:async';
import 'dart:convert';


class tab1 extends StatelessWidget {
  Future<List> _getData() async {
    final response = await http.get('https://api.androidhive.info/contacts/');

    if (response.statusCode == 200) {
      return json.decode(response.body)['contacts'];
    }
    return [];
  }

  Widget _buildListView(BuildContext context, List data) {
    return new ListView.builder(
      itemCount: data.length,
      itemBuilder: (BuildContext context, int index) {
        return new Column(
          children: <Widget>[
            new ListTile(
              title: new Text(data[index]['name']),
            ),
            new Divider(height: 2.0,),
          ],
        );
      },
    );
  }

  @override
  Widget build(BuildContext context) {

    //getData(); // fetching data from an API in build function causes performance issues, everytime setState() is called, getData() will be called...

    return new Container(
      child: new FutureBuilder(
        future: _getData(),
        builder: (BuildContext context, AsyncSnapshot snapshot) {
          if (snapshot.hasData) {
            if (snapshot.data != null) {
              return _buildListView(context, snapshot.data);
            }
          }
          return new CircularProgressIndicator();
        }
      ),
    );
  }
}