rnjs

RN

Reactive Programming Library for TypeScript

glitch-less & hot Observable only RxJS

Usage

• installation

npm install rnjs

• import

import { RN, interval } from 'rnjs'

const a: RN<number> = interval(1000, true);  // generate RN

a.subscribe( console.log );

// 0
// 1
// 2
// ...

features

• glitch-less

  • about "glitch"
    • RX GLITCHES AREN'T ACTUALLY A PROBLEM
    • Bainomugisha, Engineer, et al. "A survey on reactive programming." ACM Computing Surveys (CSUR) 45.4 (2013): 52.
  • all tasks are processed by priority-queue

• has initial value

  • all RN always has initial value
  • you can get the current value by value property (like BehaviorSubject in RxJS)

      import { RN, interval } from 'rnjs'
  
      const a: RN<number> = interval(1000, true).take(8);
  
      a.subscribe( console.log );
  
      // |0---1---2---3---4---5---6---7---|
      //                ^
      setTimeout( () => console.log( a.value ), 3500 );  // 3
  
      // |0---1---2---3---4---5---6---7---|
      //                        ^
      setTimeout( () => console.log( a.value ), 5500 );  // 5
  

• hot-RN(Observable) only

  • no cold/hot conversions are needed
  • all subscriber of an RN gets the same value at the same time

• is compatible with RxJS

  • RN has interconversion methods (toObservable, fromObservable)
  • RN has the same subscribe API as RxJS -> can be used in Angular async pipe without conversion to RxJS Observable

Coresspondence tables to RxJS

• Source RNs

RN	RxJS v6
interval	interval
fromEvent	fromEvent
fromPromise	from
fromObservable	-
manual	BehaviorSubject

• Combination methods

RN	RxJS v6
combine	combineLatest
merge	merge
-	concat
-	zip

• Operators

RN	RxJS v6
debounce	debounceTime
filter	filter
flatMap	flatMap
map	map
mapTo	mapTo
pairwise	pairwise
pluck	pluck
scan	scan
skip	skip
skipAlreadyAppeared	distinct
skipUnchanged	distinctUntilChanged
skipWhile	skipWhile
switchMap	switchMap
take	take
takeWhile	takeWhile
withLatest	withLatestFrom
withTimestamp	timestamp
-	startWith