Getting data from json by key, not index, with flutter - json

Question

I have a json table with this structure;
{id: 1, deviceid: 1, devicenumber: 11, number1: 1, number2: 2, number3: 3, number4: 0, number5: 5, date: 0000-00-00 00:00:00}
With this code, I can pull data from the json table according to the index. but what I want is to pull all the json data and search in all keys.
because i will not always know the index number but deviceid key number is always available. That's why it's to match the captured data with the data I have and get other correct information.

Answer 1

I will assume you are going to work with FutureBuilder so my answer is based around that but you should get the basics out of it
I would create a class for your json data first
Class ClassName {
final String? testText
ClassName({this.testText});
factory ClassName.fromJson(Map<String, dynamic> json) {
return ClassName(testText: json['test_text']);
}
}
Then fetch the url and parse it on your main widget, that fetch should look something like this:
Future<ClassName>? futureData;
Future<ClassName> fetchData() async {
final response = await http.get(Uri.parse(
url));
if (response.statusCode == 200) {
// If the server did return a 200 OK response,
// then parse the JSON.
return ClassName.fromJson(jsonDecode(response.body));
} else {
// If the server did not return a 200 OK response,
// then throw an exception.
throw Exception('Error');
}
}
#override
void initState() {
futureData = fetchData();
super.initState();
}}
Later on when using FutureBuilder you can use this data as a future
FutureBuilder<ClassName>(
future: futureData,
builder: (context, snapshot) {
if(snapshot.hasData) {
return Container(
child: Text(snapshot.data!.testText),)}},