need a spinner and dialog box in async API call function - flutter

Question

I have developed an image uploading API and called it an async function I need a spinner to make load until it fetches the result and after fetching the result it has to show the response received in an alert box
uploadImage() async {
final request = http.MultipartRequest(
"POST",
Uri.parse(
'https://f77f-2402-d000-a500-73e5-8c48-4e9a-dad0-c14f.in.ngrok.io/upload'));
final headers = {"Content-type": "multipart/form-data"};
request.files.add(http.MultipartFile("image",
selectedImage!.readAsBytes().asStream(), selectedImage!.lengthSync(),
filename: selectedImage!.path.split("/").last));
request.fields['userId'] = 'value';
request.headers.addAll(headers);
final response = await request.send().then((value) => null);
_isInAsyncCall = true;
http.Response res = await http.Response.fromStream(response);
final resJson = jsonDecode(res.body);
message = resJson['message'];
print(message);
setState(() {
});
My whole flutter code is here
import 'dart:convert';
import 'dart:io';
import 'package:flutter/material.dart';
import 'package:image_picker/image_picker.dart';
import 'package:http/http.dart' as http;
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({super.key});
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
// This is the theme of your application.
//
// Try running your application with "flutter run". You'll see the
// application has a blue toolbar. Then, without quitting the app, try
// changing the primarySwatch below to Colors.green and then invoke
// "hot reload" (press "r" in the console where you ran "flutter run",
// or simply save your changes to "hot reload" in a Flutter IDE).
// Notice that the counter didn't reset back to zero; the application
// is not restarted.
primarySwatch: Colors.blue,
),
home: const MyHomePage(title: 'find waste collector'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({super.key, required this.title});
// This widget is the home page of your application. It is stateful, meaning
// that it has a State object (defined below) that contains fields that affect
// how it looks.
// This class is the configuration for the state. It holds the values (in this
// case the title) provided by the parent (in this case the App widget) and
// used by the build method of the State. Fields in a Widget subclass are
// always marked "final".
final String title;
#override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
File? selectedImage;
String? message;
bool _isInAsyncCall = false;
uploadImage() async {
final request = http.MultipartRequest(
"POST",
Uri.parse(
'https://f77f-2402-d000-a500-73e5-8c48-4e9a-dad0-c14f.in.ngrok.io/upload'));
final headers = {"Content-type": "multipart/form-data"};
request.files.add(http.MultipartFile("image",
selectedImage!.readAsBytes().asStream(), selectedImage!.lengthSync(),
filename: selectedImage!.path.split("/").last));
request.fields['userId'] = 'value';
request.headers.addAll(headers);
final response = await request.send().then((value) => null);
_isInAsyncCall = true;
http.Response res = await http.Response.fromStream(response);
final resJson = jsonDecode(res.body);
message = resJson['message'];
print(message);
setState(() {
});
}
Future getImage() async {
final pickedImage =
await ImagePicker().pickImage(source: ImageSource.gallery);
selectedImage = File(pickedImage!.path);
setState(() {});
}
#override
Widget build(BuildContext context) {
// This method is rerun every time setState is called, for instance as done
// by the _incrementCounter method above.
//
// The Flutter framework has been optimized to make rerunning build methods
// fast, so that you can just rebuild anything that needs updating rather
// than having to individually change instances of widgets.
return Scaffold(
appBar: AppBar(
// Here we take the value from the MyHomePage object that was created by
// the App.build method, and use it to set our appbar title.
title: Text(widget.title),
),
body: Center(
// Center is a layout widget. It takes a single child and positions it
// in the middle of the parent.
child: Column(
// Column is also a layout widget. It takes a list of children and
// arranges them vertically. By default, it sizes itself to fit its
// children horizontally, and tries to be as tall as its parent.
//
// Invoke "debug painting" (press "p" in the console, choose the
// "Toggle Debug Paint" action from the Flutter Inspector in Android
// Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
// to see the wireframe for each widget.
//
// Column has various properties to control how it sizes itself and
// how it positions its children. Here we use mainAxisAlignment to
// center the children vertically; the main axis here is the vertical
// axis because Columns are vertical (the cross axis would be
// horizontal).
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
selectedImage == null
? Text("please pick a image to upload")
: Image.file(selectedImage!),
inAsyncCall: _isInAsyncCall,
// demo of some additional parameters
opacity: 0.5,
progressIndicator: CircularProgressIndicator(),
TextButton.icon(
style: ButtonStyle(
backgroundColor: MaterialStateProperty.all(
Color.fromARGB(255, 62, 187, 0))),
onPressed: uploadImage,
icon: Icon(Icons.upload_file_rounded, color: Colors.black38),
label: Text("Upload waste sample Image",
style: TextStyle(color: Colors.black)))
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: getImage,
child: Icon(Icons.add_a_photo),
),
// This trailing comma makes auto-formatting nicer for build methods.
);
}
}

Answer 1

modal_progress_hud library helped lot on making this task
import 'dart:convert';
import 'dart:io';
import 'package:flutter/material.dart';
import 'package:image_picker/image_picker.dart';
import 'package:http/http.dart' as http;
import 'package:flutter_progress_hud/flutter_progress_hud.dart';
import 'package:modal_progress_hud_nsn/modal_progress_hud_nsn.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({super.key});
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: const MyHomePage(title: 'find waste collector'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({super.key, required this.title});
final String title;
#override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
File? selectedImage;
String? message;
bool showSpinner = false;
uploadImage() async {
setState(() {
showSpinner = true;
});
final request = http.MultipartRequest(
"POST",
Uri.parse(
'https://f77f-2402-d000-a500-73e5-8c48-4e9a-dad0-c14f.in.ngrok.io/upload'));
final headers = {"Content-type": "multipart/form-data"};
request.files.add(http.MultipartFile("image",
selectedImage!.readAsBytes().asStream(), selectedImage!.lengthSync(),
filename: selectedImage!.path.split("/").last));
request.fields['userId'] = 'value';
request.headers.addAll(headers);
final response = await request.send();
http.Response res = await http.Response.fromStream(response);
print("reached");
final resJson = jsonDecode(res.body);
message = resJson['message'];
print(message);
setState(() {
showSpinner = false;
});
}
Future getImage() async {
final pickedImage =
await ImagePicker().pickImage(source: ImageSource.gallery);
selectedImage = File(pickedImage!.path);
setState(() {});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: ModalProgressHUD(
inAsyncCall: showSpinner,
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
selectedImage == null
? Text("please pick a image to upload")
: Image.file(selectedImage!),
TextButton.icon(
style: ButtonStyle(
backgroundColor: MaterialStateProperty.all(
Color.fromARGB(255, 62, 187, 0))),
onPressed: uploadImage,
icon: Icon(Icons.upload_file_rounded, color: Colors.black38),
label: Text("Upload waste sample Image",
style: TextStyle(color: Colors.black)))
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: getImage,
child: Icon(Icons.add_a_photo),
),
);
}
}