distinct_value_connectable_stream 1.1.1

Distinct value connectable stream for RxDart, useful for BLoC pattern

distinct_value_connectable_stream

• Distinct & Connectable & ValueStream rxdart
• Useful for flutter BLoC pattern, expose broadcast state stream to UI, can synchronous access to the last emitted item, and distinct until changed

Author: Petrus Nguyễn Thái Học

Implement BLoC

Without using package

Using package

Usage

Import distinct_value_connectable_stream:

import 'package:distinct_value_connectable_stream/distinct_value_connectable_stream.dart';

1. Constructor based

Wrap your Stream in a DistinctValueConnectableStream using constructor:

final Stream<State> state$;
final distinct$ = DistinctValueConnectableStream(state$);
final distinctSeeded$ = DistinctValueConnectableStream.seeded(
  state$,
  seedValue: State.initial(),
);

You can pass equals parameter type bool Function(T, T) to constructor, used to determined equality (default is operator ==):

final Stream<State> state$;
final bool Function(State, State) isEquals;

final distinct$ = DistinctValueConnectableStream.seeded(
  state$,
  seedValue: State.initial(),
  equals: isEquals,
);

2. Extension method based

final source$ = Stream.fromIterable([1, 2, 2, 3, 3, 3]);

// publish
final connectable$       = source$.publishValueDistinct();
final connectableSeeded$ = source$.publishValueSeededDistinct(seedValue: 0);

// share
final shared$            = source$.shareValueDistinct();
final sharedSeeded$      = source$.shareValueSeededDistinct(seedValue: 0);

All extension methods have optional parameter equals type bool Function(T, T) like constructor based

final source$ = Stream.fromIterable([1, 2, 2, 3, 3, 3]);
final connectable$ = source$.publishValueDistinct();

// Does not print anything at first
connectable$.listen(print);

// Start listening to the source Stream. Will cause the previous
// line to start printing 1, 2, 3
final subscription = connectable$.connect();

// Late subscribers will receive the last emitted value
connectable$.listen(print); // Prints 3

// Can access the latest emitted value synchronously. Prints 3
print(connectable$.value);

// Stop emitting items from the source stream and close the underlying
// BehaviorSubject
await subscription.cancel();

Features and bugs

Please file feature requests and bugs at the issue tracker.

License

MIT License

Copyright (c) 2019 Petrus Nguyễn Thái Học

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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SOFTWARE.