How to get context in the any function of StatelessWidget?

kyeonghwan picture kyeonghwan · Oct 24, 2019 · Viewed 7k times · Source

We want to show an AlertDialog after some asynchronous processing such as network processes.

When calling 'showAlertDialog ()' from an external class, I want to call it without context. Is there a good way?

class SplashPage extends StatelessWidget implements SplashView {
  BuildContext _context;
  @override
  Widget build(BuildContext context) {
    this._context = context;
    ...
  }

I've considered the above method, but I'm worried about side issues.

Help

My current code

class SplashPage extends StatelessWidget implements SplashView {

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: MyStoreColors.eats_white1_ffffff,
      body: Center(
        child: new SvgPicture.asset('assets/ic_splash.svg'),
      ),
    );
  }

  @override
  void showAlertDialog() {

    showDialog<void>(
      context: /*How to get context?*/,
      builder: (BuildContext context) {
        return AlertDialog(
          title: Text('Not in stock'),
          content: const Text('This item is no longer available'),
          actions: <Widget>[
            FlatButton(
              child: Text('Ok'),
              onPressed: () {
                Navigator.of(context).pop();
              },
            ),
          ],
        );
      },
    );
  }

  @override
  void moveToHomeContainer() {
  }

  @override
  void moveToLoginContainer() {
  }
}

Answer

J. Pablo Garc&#237;a picture J. Pablo García · Dec 31, 2020

To show an AlertDialog you need the context, but in StatelessWidget you do not have access to it directly as in StatefulWidget.

Few options are [1]:

  • passing it as GlobalKey [2]
  • passing build context as parameter to any other function inside StatelessWidget
  • use a service to inject the dialog without context [3]

Cheers.