Dart pub
RxDart is a reactive functional programming library for Google Dart, based on ReactiveX.
Google Dart comes with a very decent Streams API out-of-the-box; rather than attempting to provide an alternative to this API, RxDart adds functionality on top of it.
Dart 1.0 is supported until release 0.15.x, version 0.16.x is no longer backwards compatible and requires the Dart SDK 2.0
void main() {
const konamiKeyCodes = const <int>[
KeyCode.UP,
KeyCode.UP,
KeyCode.DOWN,
KeyCode.DOWN,
KeyCode.LEFT,
KeyCode.RIGHT,
KeyCode.LEFT,
KeyCode.RIGHT,
KeyCode.B,
KeyCode.A];
final result = querySelector('#result');
final keyUp = new Observable<KeyboardEvent>(document.onKeyUp);
keyUp
.map((event) => event.keyCode)
.bufferCount(10, 1)
.where((lastTenKeyCodes) => const IterableEquality<int>().equals(lastTenKeyCodes, konamiKeyCodes))
.listen((_) => result.innerHtml = 'KONAMI!');
}
RxDart's Observables extends the Stream class. This has two major implications:
Finally, the Observable class & operators are simple wrappers around Stream and StreamTransformer classes. All underlying implementations can be used free of the Observable class, and are exposed in their own libraries. They are linked to below.
Generally speaking, creating a new Observable is either done by wrapping a Dart Stream using the top-level constructor new Observable(), or by calling a factory method on the Observable class.
But to better support Dart's strong mode, combineLatest and zip have been pulled apart into fixed-length constructors.
These methods are supplied as static methods, since Dart's factory methods don't support generic types.
var myObservable = new Observable(myStream);
var myObservable = new Observable.merge([myFirstStream, mySecondStream]);
var myObservable = Observable.combineLatest3(
myFirstStream,
mySecondStream,
myThirdStream,
(firstData, secondData, thirdData) => print("$firstData $secondData $thirdData"));
asyncExpand)A full list of all methods and properties including those provided by the Dart Stream API (such as first, asyncMap, etc), can be seen by examining the DartDocs
var myObservable = new Observable(myStream)
.bufferCount(5)
.distinct();
Web and command-line examples can be found in the example folder.
In order to run the web examples, please follow these steps:
pub getpub serve example/webIn order to run the command line example, please follow these steps:
pub getdart example/bin/fibonacci.dart 10In order to run the flutter example, you must have Flutter installed. For installation instructions, view the online documentation.
cd into the example/flutter/github_search directoryflutter doctor to ensure you have all Flutter dependencies working.flutter packages getflutter runRefer to the Changelog to get all release notes.
stream property on Observable is now private.stream property to use a super constructor instead amb/race, combineLatest, concat, concat_eager, merge and zipswitchLatest operatoronErrorResume and onErrorRetryWith operators. These allow folks to return a specific stream or value depending on the error that occurred. buffer and window, allow to schedule using a samplerbufferbufferFuturebufferTestbufferTimebufferWhenwindowwindowFuturewindowTestwindowTimewindowWhenonCount sampler for buffer and windowonFuture sampler for buffer and windowonTest sampler for buffer and windowonTime sampler for buffer and windowonStream sampler for buffer and windowamb to raceflatMapLatest to switchMapbufferWithCount to bufferCountwindowWithCount to windowCountbufferTime transformer.windowTime transformer.delay transformer.sink are not processed correctly by Subjects.dematerialize method for Dart 2.value to BehaviorSubject. Allows you to get the latest value emitted by the subject if it exists.values to ReplayrSubject. Allows you to get the values stored by the subject if any exists.cast in favour of the now native Stream cast method.retype to return an Observable.exhaustMap map to inner observable, ignore other values until that observable completes.debounce to emit the last item of the source stream as soon as the source stream completes.debounce does not keep open any addition async timers after it has been cancelled.DoStreamTransformer to return a Future on cancel for api compatibility. PublishSubject (thanks to @pauldemarco)doOnX operators where callbacks were fired too oftencall operator / StreamTransformer entirelyStreamSubscription.call.DoStreamTransformer as a replacement for CallStreamTransformercall and CallStreamTransformer. Please use the appropriate doOnX operator / transformer.distinctUnique. Emits items if they've never been emitted before. Same as to Rx#distinct.Stream class in Dart 1.24.0, which includes this methodobservable factory -- replaced by the constructor new Observable()combineLatest -- replaced by Strong-Mode versions combineLatest2 - combineLatest9zip -- replaced by Strong-Mode versions zip2 - zip9asObservable conversion from Future-returning methods. e.g. new Observable.fromIterable([1, 2]).first.asObservable()cast operatorConcatMapStreamTransformer -- functionality is already supported by asyncExpand. Keep the concatMap method as an alias.example/example.dart
import 'package:rxdart/rxdart.dart';
/// generate n-amount of fibonacci numbers
///
/// for example: dart fibonacci.dart 10
/// outputs:
/// 1: 1
/// 2: 1
/// 3: 2
/// 4: 3
/// 5: 5
/// 6: 8
/// 7: 13
/// 8: 21
/// 9: 34
/// 10: 55
/// done!
void main(List<String> arguments) {
// read the command line argument, if none provided, default to 10
var n = (arguments.length == 1) ? int.parse(arguments.first) : 10;
// seed value: this value will be used as the
// starting value for the [scan] method
const seed = const IndexedPair(1, 1, 0);
Observable
// amount of numbers to compute
.range(1, n)
// accumulator: computes a new accumulated
// value each time a [Stream] event occurs
// in this case, the accumulated value is always
// the latest Fibonacci number
.scan((IndexedPair seq, _, __) => new IndexedPair.next(seq), seed)
// finally, print the output
.listen(print, onDone: () => print('done!'));
}
class IndexedPair {
final int n1, n2, index;
const IndexedPair(this.n1, this.n2, this.index);
factory IndexedPair.next(IndexedPair prev) => new IndexedPair(
prev.n2, prev.index <= 1 ? prev.n1 : prev.n1 + prev.n2, prev.index + 1);
@override
String toString() => '$index: $n2';
}
Add this to your package's pubspec.yaml file:
dependencies:
rxdart: ^0.17.0
You can install packages from the command line:
with pub:
$ pub get
with Flutter:
$ flutter packages get
Alternatively, your editor might support pub get or flutter packages get.
Check the docs for your editor to learn more.
Now in your Dart code, you can use:
import 'package:rxdart/rxdart.dart';
| Version | Uploaded | Documentation | Archive |
|---|---|---|---|
| 0.19.0 | Oct 12, 2018 |
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| 0.18.1 | Jul 3, 2018 |
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| 0.18.0 | Jun 19, 2018 |
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| 0.17.0 | Jun 7, 2018 |
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| 0.16.7 | May 2, 2018 |
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| 0.16.6 | Apr 2, 2018 |
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| 0.16.5 | Mar 30, 2018 |
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| 0.16.4 | Mar 29, 2018 |
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| 0.16.3 | Mar 28, 2018 |
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| 0.16.2 | Mar 28, 2018 |
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Popularity:
Describes how popular the package is relative to other packages.
[more]
|
100
|
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Health:
Code health derived from static analysis.
[more]
|
75
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Maintenance:
Reflects how tidy and up-to-date the package is.
[more]
|
100
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Overall:
Weighted score of the above.
[more]
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92
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We analyzed this package on Dec 6, 2018, and provided a score, details, and suggestions below. Analysis was completed with status completed using:
Detected platforms: Flutter, web, other
No platform restriction found in primary library
package:rxdart/rxdart.dart.
Fix lib/src/observable.dart. (-25.38 points)
Analysis of lib/src/observable.dart failed with 1 error, 1 hint:
line 1909 col 33: The method 'retype' isn't defined for the class 'Stream<T>'.
line 1908 col 17: Method doesn't override an inherited method.
| Package | Constraint | Resolved | Available |
|---|---|---|---|
| Direct dependencies | |||
| Dart SDK | >=2.0.0-dev <3.0.0 | ||
| Dev dependencies | |||
| benchmark_harness | >=1.0.0 <2.0.0 | ||
| browser | ^0.10.0+2 | ||
| coverage | ^0.9.2 | ||
| stack_trace | ^1.9.2 | ||
| test | ^0.12.34 | ||