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

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => new _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  String url =
      'https://my-json-server.typicode.com/hotgeart/app-api/categories';
  List data;

  Future<String> makeRequest() async {
    var response = await http
        .get(Uri.encodeFull(url), headers: {"Accept": "application/json"});

    setState(() {
      data = json.decode(response.body);
    });
  }

  @override
  void initState() {
    this.makeRequest();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('My App'),
        backgroundColor: Colors.green,
      ),
      body: ListView.builder(                       // <----------  WORKING
          itemCount: data == null ? 0 : data.length,
          itemBuilder: (BuildContext context, i) {
            return new ListTile(
              title: new Text(data[i]["title"]),
            );
          }),
      drawer: Drawer(
        child: ListView(
          // Important: Remove any padding from the ListView.
          padding: EdgeInsets.zero,
          children: <Widget>[
            Container(
              height: 85.0,
              child: DrawerHeader(
                child: Text(
                  'Categories',
                  style: new TextStyle(fontSize: 18.0, color: Colors.white),
                ),
                decoration: BoxDecoration(
                  color: Colors.green,
                ),
              ),
            ),
            ListView.builder(                       // <---------- NOT WORKING
                itemCount: data == null ? 0 : data.length,
                itemBuilder: (BuildContext context, i) {
                  return new ListTile(
                    title: new Text(data[i]["title"]),
                  );
                })
          ],
        ),
      ),
    );
  }
}