What is RxJS?

Overview of The ReactiveX library for JavaScript with a video talk from core team developer
31 August 2017   3549

RxJS is a library for reactive programming using Observables, to make it easier to compose asynchronous or callback-based code. This project is a rewrite of Reactive-Extensions/RxJS with better performance, better modularity, better debuggable call stacks, while staying mostly backwards compatible, with some breaking changes that reduce the API surface.

The essential concepts in RxJS which solve async event management are:

  • Observable: represents the idea of an invokable collection of future values or events.
  • Observer: is a collection of callbacks that knows how to listen to values delivered by the Observable.
  • Subscription: represents the execution of an Observable, is primarily useful for cancelling the execution.
  • Operators: are pure functions that enable a functional programming style of dealing with collections with operations like mapfilterconcatflatMap, etc.
  • Subject: is the equivalent to an EventEmitter, and the only way of multicasting a value or event to multiple Observers.
  • Schedulers: are centralized dispatchers to control concurrency, allowing us to coordinate when computation happens on e.g. setTimeout or requestAnimationFrame or others.

In this talk, you will get see how to implement a real world feature in Angular 2 with RxJS that composes user interactions, animations, AJAX and cancellation at the same time. Speaker is Ben Lesh, software engineer at Google, RxJScore team.

Frontend News Digest 18 - 24.01

How to turn a procreate drawing into a web animation, how to self-hos your web fonts, giant fines for privacy breach in EU and more
24 January 2020   75

Greetings! I hope your week went great! Here's new frontend technologies news digest.

Learn about the new browser in-development called Flow, which has a completely new multi-threaded rendering engine, Google is stopping the support for data-vocabulary, NodeJS update and other intersting posts, guides, updates and more are waiting for your attention in this digest.

Guides

  • How to Turn a Procreate Drawing into a Web Animation

Great tiny tutorial for those who use the popular iOS drawing app for creating something for your website

  • Understanding the “Initial”, “Inherit” and “Unset” CSS Keywords

Deep guide for the CSS newbies, but even skilled frontenders can find something interesting

  • How To Self-Host Your Web Fonts

Learn how to self-host web fonts so you’re not rely on Google

Articles

  • New browser on the block: Flow

An interview with Piers Wombwell, lead developer of Flow, a new browser that is being developed and it has a completely new multi-threaded rendering engine (no relation to WebKit, Gecko, or Blink)

  • Fines for European privacy breaches reach 114 million euros: report

Don't break the law

  • Sunsetting support for data-vocabulary

Starting from April 6, the data-vocabulary markup will no longer be eligible for Google rich result features

Update

  • Playwright

Node lib to automate the Chromium, WebKit and Firefox browsers

  • AVA

Test runner for Node.js

  • Node v13.7.0 (Current)

Another update for superpopular tool

Video

  • dotJS 2019 - Bert Belder - Deno