Gist

combination.md

Combination

• combineAll
• combineLatest
• concat - Subscribe to Observables in order as previous completes, emit values. (The next transaction (subscription) cannot start until the previous completes!)
• concatAll
• forkJoin
• merge - Turn multiple Observables into a single observable.
• mergeAll - Collect and subscribe to all observables.
• race
• startsWith
• withLatestFrom
• zip

conditional.md

Conditional

• defaultIfEmpty
• every
• iif
• sequenceequal

creation.md

Creation

• create
• defer
• empty
• from - Turn an array, promise, or iterable into an observable.
• fromEvent
• interval - Emit numbers in sequence based on provided timeframe.
• of - Emit variable amount of values in a sequence and then emits a complete notification.
• range
• throw
• timer

errors.md

Error Handling

• catch / catchError - Gracefully handle errors in an observable sequence.
• retry
• retryWhen

filtering.md

Filtering

• audit
• auditTime
• debounce
• debounceTime
• distinctUntilChanged
• filter - Emit values that pass the provided condition.
• first
• ignoreElements
• last
• sample
• single
• skip - Skip the provided number of emitted values. (ignore the first x emissions from the source)
• skipUntil
• skipWhile
• take - Emit provided number of values before completing. (When you are interested in only the first set number of emission)
• takeUntil - Emit values until provided Observable emits.
• takeWhile
• throttle
• throttleTime

misc.md

Utility

• do / tap - Transparently perform actions or side-effects, such as logging.
• delay
• delayWhen
• finalize / finally
• let
• repeat
• toPromise
• timeout

Misc

• throwError
• Hot vs Cold Observables
• A Producer is the source of values for your Observable (ex: Web Socket, DOM events, iterator, loop), observer.next(value)

import { Observable } from 'rxjs';

let observable = new Observable(subscriber => {
    subscriber.next(1);
    subscriber.next(2);
    subscriber.complete();
});

Promise

• new Promise((resolve, reject) => reject('Rejected!'));

multicasting.md

Multicasting

Each notification emitted by a single observable is received by multiple observers

• multicast
• publish
• share
• shareReplay

transformation.md

Transformation

• Understanding RxJS map, mergeMap, switchMap and concatMap

Flattening - subscribing to an observable

someObservable = of(..)
someObservable.pipe(
 map(..)
)
.subscribe(result
 // observable
)

standalone

 someObservable.pipe(
  map(..),
  mergeAll
 )

mapping + flattening:

 someObservable.pipe(
  mergeMap()
 )

• buffer
• bufferCount
• bufferTime
• bufferToggle
• bufferWhen
• concatMap - Queue every observable, subscribe only when last observable completes "Wait In Line". (does not subscribe to the next observable until the previous completes)
• concatMapTo
• expand
• exhaustMap - IGNORES new observables while current is emitting values "Do Not Disturb"
• groupBy
• map
• mapTo
• mergeMap / flatMap - Keep subscribing to every new observable "No strategy, Lazy". (more than one inner subscription maintained)
• partition
• pluck
• reduce
• scan
• switchMap - Unsubscribe from last observable when a NEW one arrives - "Latest & Greatest" (maintains only one inner subscription at a time)
• toArray
• window
• windowCount
• windowTime
• windowToggle
• windowWhen