RxJS

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RxJS is a library for composing asynchronous and event-based programs by using observable sequences.

For

• Asynchronous programming
• Stream

3 way to design

• Observer pattern
• Iterator pattern
• Functional programming

Observables

Can be observed, and target can be anything

3 types of notifications

• next
• error
• complete

Observer

A consumer of values delivered by an Observable

Operators

Two types of operator

• Pipeable Operators

  Can be piped to Observables using the syntax.

• Creation Operators

  Can be called as standalone functions to create a new Observables.

Commend operators

Operators

concatfilterfromfromEventmapmergeoftake

    * Creates an Observable which sequentially emits all values from the first given Observable and then moves on to the next

    concat(args: any[])

    * Filters items from source Observable

    filter<T>((value: T, index: number) => boolean)

    * Creates an Observable from an Array, an array-like object, a Promise, an iterable object, or an Observable-like object

    from<T>(input: ObservableInput<T>)

    * Creates an Observable from listening element

    fromEvent<T>(target: any, eventName: string)

    * Converts data from source Observable, and emits result as an Observable.

    map<T, R>((value: T, index: number) => R)

    * Creates an output Observable which concurrently emits all values from every given input Observable

    merge(args)

    * Converts the arguments to an observable sequence

    of<T>(args)

    * Emits only the first count values emitted by the source Observable.

    take<T>(count: number)

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1. From official website ↩