How to rebuild the whole view in flutter everytime view enters the screen

Issue

I want my page to hit the API always whenever it enters a page. For example, I am having 2 screens i.e FirstSCreen and SecondScreen. In FirstScreen I am calling an API to fetch some data. So if the user navigates from FirstScreen to SecondScreen and then comes back to FirstScreen by pressing the back button It should hit the API in FirstScreen again.

I want to know is there any inbuilt function in flutter where I should call my methods so that it can work every time it enters the screen. I have tried using didUpdateWidget() but it is not working the way I want.

initState() is also called only once the widget is loaded .. Please explain me

Solution

I have an example that might help. However, it might not cover all scenarios where your FirstScreen will always call a specific function whenever the page is displayed after coming from a different page/screen, or specifically resuming the app (coming from background -- not to be confused when coming from another screen or popping).

My example however, will always call a function when you come back from a specific screen, and you can re-implement it to other navigation functions to ensure that a specific function is always called when coming back to FirstScreen from other screens.

main.dart

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: HomePage(),
    );
  }
}

home_page.dart

class HomePage extends StatefulWidget {
  @override
  _HomePageState createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Column(
        mainAxisSize: MainAxisSize.max,
        mainAxisAlignment: MainAxisAlignment.center,
        children: <Widget>[
          Center(
            child: RaisedButton(
              onPressed: () => Navigator.of(context)
                  .push(MaterialPageRoute(builder: (context) => SecondPage()))
                  .then((value) => _reload(value)),
              child: Text('Navigate to Next Page'),
            ),
          )
        ],
      ),
    );
  }

  Future<void> _reload(var value) async {
    print(
        'Home Page resumed after popping/closing SecondPage with value {$value}. Do something.');
  }
}

second_page.dart

class SecondPage extends StatefulWidget {
  @override
  _SecondPageState createState() => _SecondPageState();
}

class _SecondPageState extends State<SecondPage> {
  @override
  Widget build(BuildContext context) {
    return WillPopScope(
      onWillPop: () async {
        Navigator.pop(context, 'Passed Value');

        /// It's important that returned value (boolean) is false,
        /// otherwise, it will pop the navigator stack twice;
        /// since Navigator.pop is already called above ^
        return false;
      },
      child: Scaffold(
        appBar: AppBar(),
        body: Column(
          mainAxisSize: MainAxisSize.max,
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Center(child: Text('Second Page')),
          ],
        ),
      ),
    );
  }
}

Answered By - Rick