Render a widget as a stream instead of a single funciton

flutter_stream_widget.dart

import 'dart:async';

import 'package:flutter/widgets.dart';

abstract class StreamWidget extends StatefulWidget {
  const StreamWidget({Key? key}) : super(key: key);

  Stream<Widget> build(BuildContext context);

  void initState() {}

  void dispose() {}

  void reassemble() {}

  Widget? buildEmpty(BuildContext context) => null;

  Widget? buildError(BuildContext context, Object? error) => null;

  @override
  State<StreamWidget> createState() => _StreamWidgetState();
}

class _StreamWidgetState extends State<StreamWidget> {
  @override
  void initState() {
    widget.initState.call();
    super.initState();
  }

  @override
  void dispose() {
    widget.dispose.call();
    super.dispose();
  }

  @override
  void reassemble() {
    widget.reassemble.call();
    super.reassemble();
  }

  @override
  Widget build(BuildContext context) {
    return StreamBuilder(
      stream: widget.build(context),
      builder: (context, snapshot) {
        if (snapshot.hasError) {
          final result = widget.buildError(context, snapshot.error);
          if (result != null) return result;
        }
        if (snapshot.hasData) {
          return snapshot.data!;
        } else {
          final result = widget.buildEmpty(context);
          if (result != null) return result;
        }
        return const SizedBox.shrink();
      },
    );
  }
}