How to set the updated text value of button throughout the app - flutter

Question

I want to set the updated text value of button throughout the app, when i click on button its text changes to current time, but when I navigate to other screen, and then come back to the screen where I created a button, it is not showing the updated text.
here is my button widget
String getTime;
//from here i get the current time
void _getTime() {
final String formattedDateTime =
DateFormat('kk:mm:ss a').format(DateTime.now()).toString();
setState(() {
getTime = formattedDateTime;
print("time");
print(getTime);
});
}
String timeInText = "Time in";
Widget _timein() {
//enable- initial case
bool firstCaseFlag = true;
if (getTimeInStatus == false && timeInButtonPressed == true) {
print("i1");
return FlatButton(
color: timeInButtonPressed ? Colors.blue[500] : Colors.blue[200],
textColor: Colors.white,
padding: EdgeInsets.all(15.0),
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(buttonRoundRadius)),
child: Row(children: <Widget>[
Icon(
Icons.timer,
),
Expanded(
child: Text(
timeInText,
textAlign: TextAlign.center,
style: TextStyle(fontSize: textFontSize),
),
),
]),
onPressed: () {
_getTime();
setState(() {
if (firstCaseFlag == true) {
timeInText = getTime; //here i set the button text to current time
timeIn = timeInText;
firstCaseFlag = false;
} else {
}
});
calltimeInApi();
});
Conditions:
There are certain conditions where button will change there state, like i have 2 button namely timein and timeout, initially timein button will be enable to click and timeout will be disable, so if user click on timein button its text change to current time and timeout button will be enable (this is all happening), and if user moved to other screen and come to home screen (where i created timein and timeout buttons) then timein button text should display that time when user click on it.
Problem:
My problem is when I moved to other screen and come to home screen timein button is enabled and not showing the time when i click on it.
please help how i can fix it.

Answer 1

I prefer using statemanagement StateProvider. here is an example just using global variable.
import 'package:flutter/material.dart';
import 'package:intl/intl.dart';
import 'package:stack_overflow/exports.dart';
String buttonText = "Click to set";
///for riverpod
///final buttonState = StateProvider((ref) => "Click to set");
class BaseWidget extends StatefulWidget {
const BaseWidget({Key? key}) : super(key: key);
#override
_BaseWidgetState createState() => _BaseWidgetState();
}
class _BaseWidgetState extends State<BaseWidget> {
void _getTime() {
final String formattedDateTime =
DateFormat('kk:mm:ss a').format(DateTime.now()).toString();
setState(() {
buttonText = formattedDateTime;
print("time");
print(buttonText);
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
body: Column(
children: [
ElevatedButton(
onPressed: () {
_getTime();
},
child: Text(buttonText),
),
ElevatedButton(
onPressed: () {
Navigator.of(context).push(MaterialPageRoute(
builder: (context) => NextWidget(),
));
},
child: Text("next"),
),
],
),
);
}
}
class NextWidget extends StatelessWidget {
const NextWidget({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return Scaffold(
body: ElevatedButton(
onPressed: () {
Navigator.of(context).pop();
},
child: Text("Back"),
),
);
}
}

Answer 2

Use state management like Provider to keep the values and then access anywhere.
Package link: https://pub.dev/packages/provider
Helpful reference: https://flutter.dev/docs/development/data-and-backend/state-mgmt/intro