how i solve this issue on flutter - flutter

Question

when I am debug this its shown a error on search bar when I try to text on emulator here is the code please resolve this thanks
LateInitializationError: Field 'name' has not been initialized.
import 'dart:async';
import 'dart:convert';
import 'package:http/http.dart' as http;
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
const MyApp({super.key});
#override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
home: HomePage(),
);
}
}
class HomePage extends StatefulWidget {
#override
State<HomePage> createState() => _HomePageState();
}
class _HomePageState extends State<HomePage> {
String url = "https://owlbot.info/api/v4/dictionary/";
String token = "7ba05536bd11ff8e22800cbda80951376c59ed84";
TextEditingController textEditingController = TextEditingController();
late StreamController _streamController;
late Stream _stream;
late Timer _debounce;
searchText() async {
if (textEditingController.text == null ||
textEditingController.text.isEmpty) {
_streamController.add(null);
return;
}
_streamController.add("waiting");
Uri uri = Uri.parse(url+textEditingController.text.trim());
http.Response response = await http.get (uri, headers: {"Authorization": "Token " + token});
_streamController.add(json.decode(response.body));
}
#override
void initState() {
super.initState();
_streamController = StreamController();
_stream=_streamController.stream;
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
backgroundColor: Colors.green,
title: Text(
"Dictionery",
style: TextStyle(color: Colors.white),
),
centerTitle: true,
bottom: PreferredSize(
preferredSize: Size.fromHeight(45),
child: Row(
children: [
Expanded(
child: Container(
margin: const EdgeInsets.only(left: 12, bottom: 11),
decoration:
BoxDecoration(
color: Colors.white,
borderRadius: BorderRadius.circular(24),
),
child: TextFormField(
onChanged: (String text) {
if (_debounce.isActive) _debounce.cancel();
_debounce = Timer(const Duration(milliseconds: 1000), () {
searchText();
},
);
},
controller: textEditingController,
decoration: InputDecoration(
hintText: "Search for Word",
contentPadding: const EdgeInsets.only(left: 24),
border: InputBorder.none,
),
),
),
),
IconButton(
icon:Icon(
Icons.search,
color: Colors.white,
),
onPressed: (){
searchText();
},
),
],
),
),
),
body: Container(
margin: EdgeInsets.all(8.0),
child: StreamBuilder(
builder:(BuildContext context, AsyncSnapshot snapshot){
if(snapshot.data== null)
{
return Center(
child: Text('Enter A Search Word'),
);
}
if(snapshot.data == "waiting"){
return Center(
child: CircularProgressIndicator(),
);
}
return ListView.builder(
itemCount: snapshot.data["defination"].length,
itemBuilder: (BuildContext context , int index)
{
return ListBody(
children: [
Container(
color: Colors.grey[300],
child: ListTile(
leading:snapshot.data["definations"][index]["image_url"] == null
? null:
CircleAvatar(
backgroundImage: NetworkImage(snapshot.data["definations"][index]["image_url"]),
),
title: Text(textEditingController.text.trim()
+"(" + snapshot.data["definations"][index]["type"]+")"),
),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: Text(
snapshot.data["defination"][index]["defination"]),
)
],
);
},
);
},
stream: _stream,
),
),
);
}
}
when i debug this and touch on screen for text its give me error late initialization

Answer 1

Current issue is _debounce has not been initialized. Instead of late, make it nullable Timer? _debounce;.
And changes will be
child: TextFormField(
onChanged: (String text) async {
if (_debounce != null && _debounce!.isActive) {
_debounce!.cancel();
_debounce = Timer(
const Duration(milliseconds: 1000),
() async {
await searchText();
},
);
}
},
Full snippet
import 'dart:async';
import 'dart:convert';
import 'package:http/http.dart' as http;
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
const MyApp({super.key});
#override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
home: HomePage(),
);
}
}
class HomePage extends StatefulWidget {
#override
State<HomePage> createState() => _HomePageState();
}
class _HomePageState extends State<HomePage> {
String url = "https://owlbot.info/api/v4/dictionary/";
String token = "7ba05536bd11ff8e22800cbda80951376c59ed84";
TextEditingController textEditingController = TextEditingController();
late StreamController _streamController;
late Stream _stream;
Timer? _debounce;
Future<void> searchText() async {
if (textEditingController.text.isEmpty) {
_streamController.add(null);
return;
}
_streamController.add("waiting");
Uri uri = Uri.parse(url + textEditingController.text.trim());
http.Response response =
await http.get(uri, headers: {"Authorization": "Token " + token});
_streamController.add(json.decode(response.body));
}
#override
void initState() {
super.initState();
_streamController = StreamController();
_stream = _streamController.stream;
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
backgroundColor: Colors.green,
title: Text(
"Dictionery",
style: TextStyle(color: Colors.white),
),
centerTitle: true,
bottom: PreferredSize(
preferredSize: Size.fromHeight(45),
child: Row(
children: [
Expanded(
child: Container(
margin: const EdgeInsets.only(left: 12, bottom: 11),
decoration: BoxDecoration(
color: Colors.white,
borderRadius: BorderRadius.circular(24),
),
child: TextFormField(
onChanged: (String text) async {
if (_debounce != null && _debounce!.isActive) {
_debounce!.cancel();
_debounce = Timer(
const Duration(milliseconds: 1000),
() async {
await searchText();
},
);
}
},
controller: textEditingController,
decoration: InputDecoration(
hintText: "Search for Word",
contentPadding: const EdgeInsets.only(left: 24),
border: InputBorder.none,
),
),
),
),
IconButton(
icon: Icon(
Icons.search,
color: Colors.white,
),
onPressed: () {
searchText();
},
),
],
),
),
),
body: Container(
margin: EdgeInsets.all(8.0),
child: StreamBuilder(
builder: (BuildContext context, AsyncSnapshot snapshot) {
if (snapshot.data == null) {
return Center(
child: Text('Enter A Search Word'),
);
}
if (snapshot.data == "waiting") {
return Center(
child: CircularProgressIndicator(),
);
}
return ListView.builder(
itemCount: snapshot.data["defination"].length,
itemBuilder: (BuildContext context, int index) {
return ListBody(
children: [
Container(
color: Colors.grey[300],
child: ListTile(
leading: snapshot.data["definations"][index]
["image_url"] ==
null
? null
: CircleAvatar(
backgroundImage: NetworkImage(snapshot
.data["definations"][index]["image_url"]),
),
title: Text(textEditingController.text.trim() +
"(" +
snapshot.data["definations"][index]["type"] +
")"),
),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: Text(
snapshot.data["defination"][index]["defination"]),
)
],
);
},
);
},
stream: _stream,
),
),
);
}
}