RxJS-toolbox - set of custom operators and handy factory functions for RxJS

*Note: updated to Angular 16.x in version 2.2.0

Installation

Install using NPM CLI
``
npm install --save rxjs-toolbox
`

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A combination operator that combines multiple sources and returns their last emitted data as well as percentage of their completion.

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#### forkJoinWithProgress
`typescript
import { ajax } from 'rxjs/ajax';
import { merge } from 'rxjs';
import { forkJoinWithProgress } from 'rxjs-toolbox';
import {tap, mergeMap, ignoreElements} from 'rxjs/operators';

const getUserDetails = userIdsList => {

const arrayOfObservables = userIdsList.map(userId =>
ajax('https://jsonplaceholder.typicode.com/comments/' + userId)
)

return forkJoinWithProgress(arrayOfObservables)
}


const result$ = getUserDetails([1, 2, 15]);

result$.pipe(
mergeMap(([finalResult, progress]) => merge(
progress.pipe(
tap((value) => console.log(${value} completed)),
ignoreElements()
),
finalResult
))
).subscribe(values => console.log(values), console.warn);

// Output:
// 33.333333333333336 completed
// 66.66666666666667 completed
// 100 completed
// final value: (3) [{…}, {…}, {…}]
`

#### waitUntil
I found an interesting #rxjs custom operator in auth0-angular interceptor codebase: waitUntil

It holds until the param observable emits first value- and then switches to the source

######Params:
isLoaded$
`typescript
isLoaded$ // - some observable we wait for
...
of(route).pipe(
waitUntil(isLoaded$)
)
...
`

#### Helper functions
##### timeRange
Function to create Observable that will emit values with specified delays
######Params:
range - array of objects with special structure [{value: , delay: },...]

isRelative - if true = next emissions is scheduled only after previous is complete (so delays are summarized).

if false - all values are scheduled at once (delay values are absolute in relation to the moment of subscription)

`typescript
const range$ = timeRange([
{value: 15, delay: 1500}, // 1500ms
{value: 15, delay: 2500} // 2500ms
])

const range2$ = timeRange([
{value: 15, delay: 1500}, // 1500ms
{value: 15, delay: 2500} // 1500+2500
], true);

`

##### finalizeWithValue
Provides (unlike original finalize from RxJS) source$'s last emitted value (if any) in format {value: }.

If source$ completes with noe emitted value - provides undefined.

Author - Ben Lesh, taken here

`typescript

from([1,3]).pipe(
finalizeWithValue((lastEmittedValue) => console.log(lastEmittedValue)) // 3
)

``

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