NoSuchMethodError: The method '[]' was called on null - Flutter - json

Question

I want to read data from this JSON in this way (PLEASE READ CODE COMMENTS):
class Profile extends StatefulWidget {
final id;
Profile({Key? key, #required this.id}) : super(key: key);
#override
_ProfileState createState() => _ProfileState();
}
class _ProfileState extends State<Profile> {
var data;
#override
void initState() {
super.initState();
void getData() async {
Response response = await get(
Uri.parse('https://en.gravatar.com/' + widget.id + '.json'));
this.data = json.decode(utf8.decode(response.bodyBytes));
// READ PLEASE >>> Data successfully is loaded from server & if you
// print this.data it will show full data in console <<< READ PLEASE
}
getData();
}
#override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
title: 'Profile | MWX Gravatar Viewer',
home: Scaffold(
appBar: AppBar(
title: Text('Profile | MGV'),
),
body: Center(
child: Column(
children: [
Text(this.data['entry'][0]['name']['familyName']), // Where raises error
],
),
),
),
);
}
}
And i get this error while rendering page:
The following NoSuchMethodError was thrown building Profile(dirty, state: _ProfileState#35267):
The method '[]' was called on null.
Receiver: null
Tried calling: []("entry")
NOTE: After a hot reload error is gone & I CAN SEE THE DATA I NEEDED ON SCREEN but every time when I want to load the page this error will be shown although I can see what I expected, after a hot reload

Answer 1

Your body might be running and not waiting for your getData() on initState. Try to check if it's null before using it:
body: Center(
child: Column(
children: [
Text(this.data != null ? this.data['entry'][0]['name']['familyName'] : 'no data'), // Where raises error
],
),
),
Or use a FutureBuilder.

Answer 2

This is because you are calling network request and at same time you are using data which is null by default so you can use either FutureBuilder() or handle error by null check