rxjs-stream

rxjs-stream

This is a simple library for converting to and from NodeJS stream and rxjs 6.

This was created to fill the gap left by rx-node, which only works with rxjs 4.

Installation

npm install --save rxjs rxjs-stream

Usage

Writing to a stream.

import {rxToStream} from 'rxjs-stream';

let data = 'This is a bit of text to have some fun with';
let src = Rx.Observable.from(data.split(' '));
rxToStream(src).pipe(process.stdout);

Writing objects to a stream

To write objects, you must pass in the ReadableOptions with objectMode to be true: { objectMode: true }

import {rxToStream} from 'rxjs-stream';

let data = 'This is a bit of text to have some fun with';
let wordObj = data.split(' ').map(text => ({ text }));
let src = Rx.Observable.from(wordObj);
let stream = rxToStream(src, { objectMode: true });

Read from a stream

import {rxToStream, streamToStringRx} from 'rxjs-stream';

// Read stdin and make it upper case then send it to stdout
let ob = streamToStringRx(process.stdin)
    .map(text => text.toUpperCase());

rxToStream(ob).pipe(process.stdout);

Performance

It is recommended to buffer observable values before sending them to the stream. Node streams work better with fewer calls of a large amount of data than with many calls with a small amount of data.

Example:

import * as loremIpsum from 'lorem-ipsum';
import {rxToStream} from 'rxjs-stream';

let book = loremIpsum({ count: 1000, format: 'plain', units: 'paragraphs'});
let words = Rx.Observable.from(book.split(/\b/));
let wordsBuffered = words.bufferCount(1000).map(words => words.join(''));
let stream = rxToStream(wordsBuffered);

stream.pipe(process.stdout);

Compatibility

This library is tested with Node 10 and above.

Changelog

3.3.0 (2021-07-18)

Bug Fixes

• Add option to subscribe immediately to an observable. (#109) (81fcec5), closes #106