display alert when data is changed using flutter? - flutter

Question

My screen look like thisI have trying to display alert when snapshot.data value has been changed.i try the if else condition
import 'dart:async';
import 'dart:convert';
import 'package:assets_audio_player/assets_audio_player.dart';
import 'package:http/http.dart' as http;
import 'package:flutter/material.dart';
import'package:flutter_custom_clippers/flutter_custom_clippers.dart';
import 'package:tv_dashboard/pages/test.dart';
//import 'package:assets_audio_player/assets_audio_player.dart';
class DashBoard extends StatefulWidget {
#override
_DashBoardState createState() => _DashBoardState();
}
var now = new DateTime.now();
String g = ('${now.day}-${now.month}-${now.year}');
AnimationController _controller;
Animation<double> _animation;
class _DashBoardState extends State<DashBoard> with TickerProviderStateMixin {
Timer timer;
int counter = 0;
Test data = Test();
Future<List<dynamic>> fetchUsers() async {
String url = 'http://us.rdigs.com/jsonData.php';
var result = await http.get(url, headers: {
'Content-Type': 'application/json',
'Accept': 'application/json',
});
if (result.statusCode == 200) {
//print(result.body);
//playSound();
return json.decode(result.body);
} else {
// If the server not return a 200 OK ,
// then throw the exception.
throw Exception('Failed');
}
}
playSound() async {
AssetsAudioPlayer audioPlayer = AssetsAudioPlayer();
audioPlayer.open(Audio('assets/Ring.mp3'));
}
String name(dynamic name) {
return name['name'];
}
String leads(dynamic leads) {
return leads['leads'];
}
#override
void initState() {
super.initState();
timer = Timer.periodic(Duration(seconds: 5), (Timer t) => addValue());
}
void addValue() {
setState(() {
//playSound();
counter++;
});
}
void alertBox() async {
await fetchUsers();
Container(
padding: EdgeInsets.only(left: 300),
child: AlertDialog(
title: Text('Alert Data'),
),
); //Use the response in the dialog
}
var totalLeads = 0;
var countLead = 0;
var allLeads;
#override
Widget build(BuildContext context) {
alertBox();
//playSound();
return Scaffold(
// backgroundColor: Color.fromRGBO(198, 159, 169, 1),
body: Column(
children: [
ClipPath(
clipper: OvalBottomBorderClipper(),
child: Container(
padding: EdgeInsets.only(top: 5),
height: 70,
color: Colors.cyan[100],
child: Center(
child: Column(
children: [
Text(
"Total Leads",
style: new TextStyle(fontSize: 28.0, fontFamily: 'Michroma'),
),
Text(
totalLeads.toString(),
style: new TextStyle(
fontSize: 25.0,
),
)
],
)),
),
),
Expanded(
child: FutureBuilder<List<dynamic>>(
future: fetchUsers(),
builder: (context, snapshot) {
if (snapshot.hasData) {
//total leads
//alertBox();
totalLeads = snapshot.data
.map<int>((m) => int.parse(m["leads"]))
.reduce((a, b) => a + b);
return GridView.builder(
itemCount: snapshot.data.length,
gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
crossAxisCount: 6,
childAspectRatio:
MediaQuery.of(context).size.height / 350,
),
padding: EdgeInsets.all(8),
itemBuilder: (BuildContext context, int index) {
return Card(
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.only(
topLeft: Radius.circular(20),
bottomRight: Radius.circular(20)),
side: BorderSide(color: Colors.black)),
child: Column(
children: <Widget>[
Container(
padding: EdgeInsets.only(top: 10),
child: Column(
children: [
Text(
name(snapshot.data[index]),
style: new TextStyle(
fontSize: 25.0,
),
),
Container(
padding: EdgeInsets.only(top: 12),
child: Text(
leads(snapshot.data[index])
.toString(),
style: new TextStyle(
fontSize: 26.0,
color: Colors.blue),
))
],
)),
],
),
);
});
} else if (snapshot.hasError) {
return Text("${snapshot.error}");
} else {
return Center(child: CircularProgressIndicator());
}
}))
],
));
}
}
totalLeads is count of my all int value
sum is temp variable
my problem is when data is changed in json string then display the alert box in flutter

Answer 1

When data changed in string, you can show AlertDialog widget:
Future<void> showErrorDialog() async {
return showDialog<void>(
context: context,
builder: (BuildContext context) {
return AlertDialog(
title: Text('Error'),
content: SingleChildScrollView(
child: Text(
'Error message',
),
),
actions: <Widget>[
TextButton(
child: Text('Ok'),
onPressed: () => Navigator.of(context).pop(),
),
],
);
},
);
}