Try Something New Today – ReactJS

Sarah C

January 28th, 2015

Sometimes it seems like AngularJS is the only frontend game in town. There are reasons for that. It’s sophisticated, it’s a game-changer for web design that makes things better right now, and the phenomenal rate of adoption has also led to all kinds of innovative integrations.

However, when all you have is a directive, every problem starts to look like an ng-, as they say. Now and again, we all like the novelty of change. As the first signs of spring emerge from the snow, our techie fancies lightly turn to thoughts of components.

So, like a veritable Sam-I-Am, let me press you to try something you may not have tried before.* Today’s the day to take ReactJS for a test drive.

So what’s the deal with React, then?

ReactJS was developed by Facebook, then open sourced last year. Lately, it’s been picking up speed. Integrations have improved, and now that Facebook have also open sourced Flux, we’re hearing a lot of buzz about what React can do for your UI design. (Flux is an application pattern. You can read more about its controller-free philosophy at Facebook’s GitHub page.)

Like so many things, React isn’t quite a framework and it isn’t quite a library. Where React excels is in generating UI components that refresh with data changes. With disarming modesty, React communicates the smallest changes on the server side to the browser quickly, without having to re-render anything except the part of the display that needs to change. Here’s a quick run through of React’s most pleasing features. (ReactJS also has a good sense of humour, and enjoys long walks along the beach at sunset.)

Hierarchical components

ReactJS is built around components: the new black of web dev. Individual components bundle together the markup and logic as handy reusable treats. Everyone has their own style when developing their apps, but React’s feel and rhythm encourages you to think in components.

React’s components are also hierarchical – you can nest them and have them inherit properties and state. There are those who are adamant that this is the future of all good web-app code.

Minimal re-rendering

Did you catch my mention of ‘state’ up there? React components can have state. Let the wars begin right now about that, but it brings me to the heart of React’s power. React reacts. Any change triggers a refresh, but with minimal re-rendering. With its hierarchical components, React is smart enough to only ever refresh and supply new display data to the part of the component that needs it, not the entire thing. That’s good news for speed and overhead.

Speedy little virtual dom

In fact, ReactJS is light in every sense. And it owes a lot of its power to its virtual DOM. Rather than plug into the DOM directly, React renders every change into a virtual DOM and then compares it against the current DOM. If it sees something that needs to be changed in the view, React gets to work on changing just that part, leaving everything else untouched.

Fun to write

React mixes HTML and JavaScript, so you can refer to HTML elements right there inside your <script>. Yes, okay, that’s ‘fun’ for a given value of fun. The kind where dorks get a little giddy about pleasing syntax. But we’re all in this together, so we might as well accept ourselves and each other.

For example, here’s a simple component rendering from an official tutorial:

// tutorial1.js
var CommentBox = React.createClass({
render: function() {
   return (
     <div className="commentBox">
       Hello, world! I am a CommentBox.
<CommentBox />,

This is JSX syntax, which React uses instead of defining templates within a string. Pretty, right?

Reactive charts and pictures

With luck, at this point, your coffee has kicked in and you’re beginning to think about possible use cases where React might be a shiny new part of your toolkit. Obviously, React’s going to be useful for anything with lots of real-time activity. As a frontend for a chat client, streaming news, or a dashboard, it’s got obvious powers. But think a little further and you’ll see a world of other possibilities. React can also handle SVG for graphics and charts, with the potential to create dynamic and malleable visualisations even without D3.


One last-but-not-least selling point: web apps built with this framework don’t scare the Google Spiders. Because everything’s passed to the client side and into the DOM having already had its shoes shined by the virtual DOM, it’s very easy to make apps legible for search engines as well as for people, allowing your stored data to be indexed and boost your SEO by reflecting your actual content.

Give it a shot and do some experimenting. Have you had any wins or unexpected problems with React? Or are you thinking of giving it a whirl for your next app? We’re going to try it out for some in-house data viz, and may possibly even report back. What about you?

*Do not try ReactJS with a goat on a boat without taking proper safety precautions. (With a mouse in a house is fine and, indeed, encouraged.)

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