How to transfer the text entered in the input to another screen? - flutter

Question

The application first displays the With text: Entered text screen. And there is a button when clicked on which the user gets to another screen where he needs to enter text. It is necessary for me that when the user has entered the text, when returning back to the first screen, this text is displayed. How can this be done?
My code:
import 'package:flutter/material.dart';
class TextScreen extends StatefulWidget {
const TextScreen({Key? key}) : super(key: key);
#override
State<TextScreen> createState() => _TextScreenState();
}
class _TextScreenState extends State<TextScreen> {
final textController = TextEditingController();
#override
void dispose() {
textController.dispose();
super.dispose();
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: const Text('Enter data'),
),
body: Padding(
padding: const EdgeInsets.symmetric(horizontal: 16.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
mainAxisAlignment: MainAxisAlignment.center,
children: [
TextField(
controller: textController,
decoration: InputDecoration(labelText: 'Message'),
),
const SizedBox(
height: 20,
),
],
)),
);
}
}

Answer 1

You can add a result when navigating back
Navigator.of(context).pop("test");
And the you can use the result in the previos screen
Navigator.push(
context,
MaterialPageRoute(builder: (context) => TextScreen()),
).then((result) => { ... });

Answer 2

There are several ways to do this. The main question is if you have a specific submit action, such as a button, to confirm using the new text or if the newly entered text should always be used, also when the user uses the back button or back swipe gesture to go back to the previous screen.
Only through submit action
If you want to consider the back button as a 'cancel' operation, and only want to update the value with a specific button, you can return the new value with the Navigator: Navigator.of(context).pop(updatedValue). Where the page was pushed, you can await this result: final updatedValue = await Navigator.of(context).push(editPageRoute);
If you always want the value to update
In this case, you'll need to update this new text in a component that lives above the Navigator which is likely provided by your MaterialApp (or other WidgetApp).
To do so, you can wrap the Navigator in another widget by using the builder function of the MaterialApp. This widget can be obtained through the widget tree and is available in both pages. You can use InheritedWidget or provider to obtain this widget.
You could also keep a component outside of your widget tree that holds this text. Using get_it might be a solution for that, but riverpod would probably allow you to do so as well.