Future Builder in Flutter

Use Future Builder in Flutter class is a widget for helping the user to make a selection in material design. If the future is created at the same time as the FutureBuilder, then every time the FutureBuilder’s parent is rebuilt, the asynchronous task will be restarted.

In Flutter, Future needs to be gotten before either through a difference in state or a change in dependencies. FutureBuilder is a Widget that will assist you with executing some asynchronous functions and based on that function’s outcome your UI will update.

You can find out more Flutter app development company page.

To implement the Future Builder do follow the steps mentioned below.

1.) Create a Scaffold.

2.) Create the Timing schedule.

3.) Use the FutureBuilder widget.

1.) Create a Scaffold. :

Inside Scaffold widgets, it Implements the basic material design visual layout structure. First, initialize the main app as a stateless widget.

This class provides APIs for showing drawers and bottom sheets. We can add the background color inside the scaffold widget.

It also supports special Material Design components, such as Drawers, AppBars, and SnackBars.

  void main() {
    runApp(const MyApp());
  }

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        debugShowCheckedModeBanner: false,
        title: 'Future Builder Demo',
        theme: ThemeData(
        primarySwatch: Colors.blue,
    ),
    home: _DemoFutureBuilderScreen(),
    );
  }
}

void main() {

runApp(const MyApp());

}

class MyApp extends StatelessWidget {

const MyApp({Key? key}) : super(key: key);

// This widget is the root of your application.

@override

Widget build(BuildContext context) {

return MaterialApp(

debugShowCheckedModeBanner: false,

title: 'Future Builder Demo',

theme: ThemeData(

primarySwatch: Colors.blue,

home: _DemoFutureBuilderScreen(),

);

}

2.) Create the Timing schedule.

Now, For timing, we can create a widget rebuilding scheduled by the completion of the future, using State.setState, but is otherwise decoupled from the timing of the future. The builder callback is called at the discretion of the Flutter pipeline, and will thus receive a timing-dependent sub-sequence of the snapshots that represent the interaction with the future.

  final Future<String> _countDown = Future<String>.delayed(
    const Duration(seconds: 5),
        () => 'Data Loaded',
  );

final Future<String> _countDown = Future<String>.delayed(

const Duration(seconds: 5),

() => 'Data Loaded',

);

3.) Use the FutureBuilder widget.

In future builder, it calls the future capacity to wait for the outcome, and when it creates the outcome it calls the builder function where we assemble the widget.

The full code is mentioned below.

import 'package:flutter/material.dart';

  void main() {
    runApp(const MyApp());
  }
  
class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        debugShowCheckedModeBanner: false,
        title: 'Future Builder Demo',
        theme: ThemeData(
        primarySwatch: Colors.blue,
    ),
    home: _DemoFutureBuilderScreen(),
    );
  }
}

class _DemoFutureBuilderScreen extends StatelessWidget {
  final Future<String> _countDown = Future<String>.delayed(
    const Duration(seconds: 5),
        () => 'Data Loaded',
  );


  Widget build(BuildContext context) {
    return FutureBuilder<String>(
      future: _countDown, // a previously-obtained Future<String> or null
      builder: (BuildContext context, AsyncSnapshot<String> snapshot) {
        List<Widget> children;
        if (snapshot.hasData) {
          children = <Widget>[
            Icon(
              Icons.check_circle_outline,
              color: Colors.green,
              size: 60,
            ),
            Padding(
              padding: const EdgeInsets.only(top: 16),
              child: Text('Result: ${snapshot.data}'),
            )
          ];
        } else if (snapshot.hasError) {
          children = <Widget>[
            Icon(
              Icons.error_outline,
              color: Colors.red,
              size: 60,
            ),
            Padding(
              padding: const EdgeInsets.only(top: 16),
              child: Text('Error: ${snapshot.error}'),
            )
          ];
        } else {
          children = <Widget>[
            SizedBox(
              child: CircularProgressIndicator(),
              width: 60,
              height: 60,
            ),
            const Padding(
              padding: EdgeInsets.only(top: 16),
              child: Text('Awaiting result...'),
            )
          ];
        }
        return Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            crossAxisAlignment: CrossAxisAlignment.center,
            children: children,
          ),
        );
      },
    );
  }
}

import 'package:flutter/material.dart';

void main() {

runApp(const MyApp());

}

class MyApp extends StatelessWidget {

const MyApp({Key? key}) : super(key: key);

// This widget is the root of your application.

@override

Widget build(BuildContext context) {

return MaterialApp(

debugShowCheckedModeBanner: false,

title: 'Future Builder Demo',

theme: ThemeData(

primarySwatch: Colors.blue,

home: _DemoFutureBuilderScreen(),

);

}

class _DemoFutureBuilderScreen extends StatelessWidget {

final Future<String> _countDown = Future<String>.delayed(

const Duration(seconds: 5),

() => 'Data Loaded',

);

Widget build(BuildContext context) {

return FutureBuilder<String>(

future: _countDown, // a previously-obtained Future<String> or null

builder: (BuildContext context, AsyncSnapshot<String> snapshot) {

List<Widget> children;

if (snapshot.hasData) {

children = <Widget>[

Icon(

Icons.check_circle_outline,

color: Colors.green,

size: 60,

Padding(

padding: const EdgeInsets.only(top: 16),

child: Text('Result: ${snapshot.data}'),

)

];

} else if (snapshot.hasError) {

children = <Widget>[

Icon(

Icons.error_outline,

color: Colors.red,

size: 60,

Padding(

padding: const EdgeInsets.only(top: 16),

child: Text('Error: ${snapshot.error}'),

)

];

} else {

children = <Widget>[

SizedBox(

child: CircularProgressIndicator(),

width: 60,

height: 60,

const Padding(

padding: EdgeInsets.only(top: 16),

child: Text('Awaiting result...'),

)

];

}

return Center(

child: Column(

mainAxisAlignment: MainAxisAlignment.center,

crossAxisAlignment: CrossAxisAlignment.center,

children: children,

);

}

We can now run the app on how to create Future Builder in a flutter.

Finally, we have implemented the flow of creating Future Builder in a flutter.

Hope this blog helps you to create Future Builder in a flutter.

So, I hope it will help you out in understanding and get a brief idea about it.

You can also check these links.

Another mentioned URL.

For more understanding please can go through this Link:

That’s all, You can enjoy your Future Builder implementation in a flutter.

Thank you very much.

flutter

Priyanka Kumari

28 Apr, 2023
Updated by - Priyanka Kumari
30 Dec, 2022
Created by - Priyanka Kumari

. . .

Future Builder in Flutter

To implement the Future Builder do follow the steps mentioned below.

1.) Create a Scaffold. :

2.) Create the Timing schedule.

3.) Use the FutureBuilder widget.

The full code is mentioned below.

Finally, we have implemented the flow of creating Future Builder in a flutter.

You can also check these links.

Another mentioned URL.

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