uigitdev/stream_holder

Stream and data holder class, which helps to ensure reusability and reduce the number of lines of code.

Stream and data holder class, which helps to ensure reusability and reduce the number of lines of code.

Usage

import 'dart:math';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:uigitdev_stream_holder/src/stream_holder.dart';
import 'package:uigitdev_stream_holder/src/stream_holder_builder.dart';

void main() {
  runApp(
    MultiProvider(
      providers: [
        ChangeNotifierProvider<MainProvider>(create: (_) => MainProvider()),
      ],
      child: const MyApp(),
    ),
  );
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: SizedBox(
          width: double.maxFinite,
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            crossAxisAlignment: CrossAxisAlignment.center,
            children: [
              _countDataBuilder(),
              _countButton(),
              _errorButton(),
              _emptyButton(),
            ],
          ),
        ),
      ),
    );
  }

  Widget _emptyButton() {
    return Consumer<MainProvider>(
      builder: (context, provider, _) {
        return TextButton(
          onPressed: () => provider.countStreamHolder.addData(null),
          child: Text('Empty'),
        );
      },
    );
  }

  Widget _errorButton() {
    return Consumer<MainProvider>(
      builder: (context, provider, _) {
        return TextButton(
          onPressed: () => provider.countStreamHolder.addError(ErrorHint('some-error')),
          child: Text('Add Error'),
        );
      },
    );
  }

  Widget _countButton() {
    return Consumer<MainProvider>(
      builder: (context, provider, _) {
        return TextButton(
          onPressed: () => provider.countStreamHolder.addData(Random().nextInt(500)),
          child: Text('+'),
        );
      },
    );
  }

  Widget _countDataBuilder() {
    return Consumer<MainProvider>(
      builder: (context, provider, _) {
        return StreamHolderBuilder<int?>(
          streamHolder: provider.countStreamHolder,
          builder: (context, state, data, error) {
            switch (state) {
              case StreamHolderState.none:
                return const CircularProgressIndicator();
              case StreamHolderState.hasData:
                return Text('success: $data');
              case StreamHolderState.hasError:
                return Text('error: ${error.toString()}');
            }
          },
        );
      },
    );
  }
}

class MainProvider extends ChangeNotifier {
  final countStreamHolder = StreamHolder<int?>(null);
}