Pure functions are functions which for certain input always returns the same output without modifying its surroundings. So, they are free from side effects. Because of that feature they are easy to test and highly reliable part of your system. Why only a part? There is a lot of different side effects and it’s more probably than not that your app is full of them. Every DOM mutation, API request, pushState or even console.log is a side effect. It’s hard to imagine an useful application without side effects.
devBlog of Michal Zalecki
At first sight, RxJS is blown up lodash but for dealing also with async. In reality, it’s so much more than that. With a few simple operators, you can implement a Redux-like state machine, schedule animation or deal with any type of events no matter whether it’s WebSocket message or filling in the text input.
On 16th December I had a pleasure to give the presentation about Flux architecture pattern on ReactJS Wrocław meetup. Flux is well known in React community and has many different implementations not without reason. After short introduction I pointed out 7 common problems and compered how different implementations are trying to solve them.
When your SPA is growing its download time is getting longer and longer. That’s not going hand in hand with better user experience (remainder: that’s why we are doing SPAs). More code means bigger files and when minification isn’t enough for you the only thing you can do for your user is stop making him to download whole app at once. Here lazy loading comes in handy. Instead downloading every file let your user download only files which he need NOW, at this very page.
ECMAScript 6 (also known as ECMAScript 2015) is the new, but not the newest (ECMAScript 7), version of ECMAScript standard and it’s based on ECMAScript 5.1. Since August 2014, ES6 is feature frozen. After publication process which will start in March 2015, ES6 will be finished in June 2015. Despite that ES6 is not finished yet there aren’t any good reasons to not use it today thanks to great tools like Traceur from Google or Babel. ES6 is solving many real-life problems which, as programmers, we are facing on a daily basis not only in browsers but also on the server side.