Using Flutter Provider to Refresh a Page

When building a Flutter app, managing state is crucial for maintaining its functionality and user experience. In this article, we will explore how to use the provider package to manage state in our application and refresh a page when needed.

First, let's create a new Flutter project using `flutter create flutter_provider_example`. This will give us a basic structure for our app.

Next, we need to add the provider plugin to our `pubspec.yaml` file. To do this, open your terminal and run the following command:

```

flutter pub add provider

```

Once installed, let's create a global function that we can call from almost all screens of our app. In my case, I have a settings screen where users can update their account information.

To use the provider package, we need to define a `ChangeNotifier` class that will handle state changes for us. Let's create a new file called `user_data_notifier.dart` and add the following code:

```dart

import 'package:flutter/material.dart';

class UserDataNotifier with ChangeNotifier {

String _userName = '';

String get userName => _userName;

void updateUserName(String name) {

_userName = name;

notifyListeners();

}

```

In this example, we have a `UserDataNotifier` class that extends `ChangeNotifier`. It has a `_userName` property and an `updateUserName` method. When the `updateUserName` method is called, it updates the `_userName` property and notifies any listeners.

Now, let's create a new screen where we can update the user's name. In my case, I have a settings screen with a text field and a button to save the changes.

```dart

import 'package:flutter/material.dart';

import 'package:provider/provider.dart';

class SettingsScreen extends StatefulWidget {

@override

_SettingsScreenState createState() => _SettingsScreenState();

}

class _SettingsScreenState extends State {

final TextEditingController _controller = TextEditingController();

@override

Widget build(BuildContext context) {

return Scaffold(

appBar: AppBar(

title: Text('Settings'),

body: Padding(

padding: const EdgeInsets.all(20.0),

child: Column(

children: '

TextFormField(

controller: _controller,

decoration: InputDecoration(

labelText: 'Name',

SizedBox(height: 20),

ElevatedButton(

onPressed: () {

Provider.of(context, listen: false).updateUserName(_controller.text);

child: Text('Save'),

)

);

}

```

In this example, we have a `SettingsScreen` widget with a text field and a button to save the changes. When the button is pressed, it updates the user's name using the `updateUserName` method of our `UserDataNotifier`.

To refresh the page when the user saves their changes, we can use the `ChangeNotifier` class provided by the provider package. We can wrap our app with the `ChangeNotifierProvider` widget and pass an instance of our `UserDataNotifier` to it.

```dart

import 'package:flutter/material.dart';

import 'package:provider/provider.dart';

void main() {

runApp(

ChangeNotifierProvider(

create: (context) => UserDataNotifier(),

child: MyApp(),

);

}

class MyApp extends StatelessWidget {

@override

Widget build(BuildContext context) {

return MaterialApp(

title: 'Flutter Demo',

theme: ThemeData(

primarySwatch: Colors.blue,

home: SettingsScreen(),

);

}

```

In this example, we have a `MyApp` widget that wraps our app with the `ChangeNotifierProvider` widget and passes an instance of our `UserDataNotifier` to it.

When we save and refresh the application, the user's name will be updated and reflected on all screens that use the `UserDataNotifier`.

In this article, we learned how to use the provider package to manage state in our Flutter app. We created a global function that updates the user's name and refreshed the page when needed. By using the `ChangeNotifier` class provided by the provider package, we can track state changes throughout our application and refresh the page accordingly.

I hope this tutorial has been helpful in understanding how to use the provider package in Flutter. Happy coding!

Flutter provider refresh page