Use of snackbar as a widget

ghz 8months ago ⋅ 58 views

I want to use a Snackbar instead of the ErrorScreen for code as below. How is that possible?

@override
  Widget build(BuildContext context) {
    return BlocBuilder<AuthCubit, AuthState>(
      builder: (context, state) {
        if (state is AuthSuccess) {
          return buildSuccessScreen(state);
        } else if (state is AuthError) {
          return ErrorScreen(state.message);
        } else if (state is AuthPrompt) {
          return _LoginForm(buildSuccessScreen);
        } else if (state is AuthEmailVerification) {
          return const VerifyEmail();
        } else {
          return const Scaffold(
            body: Center(child: CircularProgressIndicator()),
          );
        }
      },
    );
  }
}

Answers

To replace the ErrorScreen with a Snackbar, you can show a Snackbar at the Scaffold level when the state is AuthError. Here's how you can modify your code to achieve this:

@override
Widget build(BuildContext context) {
  return BlocBuilder<AuthCubit, AuthState>(
    builder: (context, state) {
      if (state is AuthSuccess) {
        return buildSuccessScreen(state);
      } else if (state is AuthError) {
        // Show Snackbar instead of ErrorScreen
        WidgetsBinding.instance.addPostFrameCallback((_) {
          ScaffoldMessenger.of(context).showSnackBar(
            SnackBar(
              content: Text(state.message),
              duration: Duration(seconds: 3),
            ),
          );
        });
        return _LoginForm(buildSuccessScreen);
      } else if (state is AuthPrompt) {
        return _LoginForm(buildSuccessScreen);
      } else if (state is AuthEmailVerification) {
        return const VerifyEmail();
      } else {
        return const Scaffold(
          body: Center(child: CircularProgressIndicator()),
        );
      }
    },
  );
}

In this modified code:

  • When the state is AuthError, a Snackbar is shown using ScaffoldMessenger.of(context).showSnackBar().
  • The Snackbar contains the error message retrieved from state.message.
  • addPostFrameCallback() ensures that the SnackBar is shown after the current frame is painted, preventing any layout issues.
  • Duration specifies how long the Snackbar should be displayed.

With this implementation, when the authentication encounters an error, a Snackbar will be displayed to inform the user about the error message.

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