Announcing ReactJS Tokyo

Have you ever wondered how other people write React apps? There are often multiple ways to solve the same problem, but finding the best way doesn’t have to mean implementing each of them yourself!

So what I’m trying to say is that if you don’t like learning things the hard way and you’re in Tokyo, you should totally come along to the first ever ReactJS Tokyo meetup.

All skill levels of English, 日本語 and JavaScript are welcome. Snacks and drinks will be provided. It will take place on Thursday, 28th July in Roppongi, and places are limited. So make sure to register early.

Look forward to seeing you there!

Should I use shouldComponentUpdate?

So you heard React was fast, and decided to give it a go. You grabbed a boilerplate, started working through it, and noticed shouldComponentUpdate and PureRenderMixin. Some googling reveals these are the things you use to make React fast. But wasn’t React already fast?

The answer is that React is fast… sometimes. The other times, you should use shouldComponentUpdate. But when are the other times? Wouldn’t it be so much easier if there was just a simple yes-no question which you could ask to decide whether to use shouldComponentUpdate or not? And wouldn’t you believe it, there is!

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How I learned to stop worrying and love the JSX

So you’ve heard the commotion about React, and thought you’d take a look. And you’ve liked what you’ve seen! Or you did, until you saw this:

<div onClick={this.handleClick}>JSX butters my toast</div>

OK. You’re happy to give a new technology the benefit of the doubt. But this? Didn’t we escape PHP years ago? And what ever happened to separation of concerns?!

But I’m here to reassure you that not everything is as it seems. The above code is not JavaScript-in-HTML. If anything it actually promotes separation of concerns, especially compared to “competitor framework A”. And its best feature?

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Universal React: You’re doing it wrong

So you’ve got the React basics down, and you’ve decided to put together an app. Given that React runs on both the server side and the client side, it seems that making a Universal (or Isomorphic) app is a no-brainer. Or it did until you’d spend hours trying to figure out how to set up Node.JS and Express, and make it distinguish between requests for JSON and HTML. And that’s if you’re lucky enough to not already have a server written in Rails or Java – at which point you’re probably considering rewriting your entire backend. But wasn’t Universal supposed to be a no-brainer?

While rendering server-side certainly has its benefits, they are by no means… universal. So the question is: should your app be Universal?

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React with Babel Cheatsheet

One of my favourite blog posts on the internet is Steven Luscher‘s guest post on the Babel blog, React on ES6+. It manages to be both incredibly helpful and easy to understand, while being short enough that when you hit the end you’re like “wait, is that it?”.

And as it happens, one of the most frequent requests I get is for an updated version of my React cheatsheet, showing the newer React component syntax using ES6 classes and React.Component.

So what I’m trying to say is I’ve finally gotten my act together and made your React/ES6 cheatsheet. And I’ve based it on Steven Luscher’s post. I’ve even made it free; as in speech, and as in beer:

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Should I use React.createClass, ES6 Classes or stateless functional components?

So you’ve decided to build a React component. You know what it will do, what it’s called, and where it’ll go. But when you open your editor and go to write the first line, you’re confronted with the decision between three different ways to declare it? Why three? And which one should you use?

Luckily, this decision doesn’t need to be a hindrance. In fact, with a little history and two simple rules, it’ll only take a few seconds to get on with the job of writing your component. And without further adieu, here’s the first rule:

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Simple Routing with Redux and React

TL;DR? Clone the Starter Kit instead.

Have you ever wished that libraries for React apps could be simpler?

Sure, you know that there are cases when all the bells and whistles are an advantage — but for you, features aren’t as important as clarity. Instead of giving up control to fast-moving libraries written by big names, you want to understand what is going on under the hood. And instead of sifting through documentation on twenty different tools before getting started, you want to get stuck into it right now.

And you’re not alone! In fact, most of my work has involved small projects which don’t make use of many of the features provided by popular routing libraries. So instead, I’ve rolled my own routing using Redux and React. And it is so simple that everything you need to know fits into this short guide.

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The Complete Guide to ES6 with Babel 6

Over the last year, Babel has become the go-to tool for transforming ES2015 and JSX into boring old JavaScript. Which makes it kinda hilarious that by default, Babel 6 no longer transforms either:

james$ echo "export function component() { return <div /> }" | babel
SyntaxError: unknown: Unexpected token (1:37)
> 1 | export function component() { return <div /> }
    |                                      ^

So what happened? Well, in the brave new world of Babel 6, you need to choose which transforms to run. This promotes separation of concerns, a decidedly good thing. It also tends to promote a “shit shit” moment when suddenly nothing works.

But luckily, this doesn’t mean that you’ll now need to comb through the bug trackers and documentation for seemingly every part of your build system. Instead, just follow these five guides to get your app, libraries, tasks and tests modernised in no time!

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Teaching Gulp ES6, with Babel 6

This guide is part of The Complete Guide to ES6 with Babel 6 series. If you’re having trouble upgrading to Babel 6, start with Six Things You Need To Know About Babel 6.

So you’ve written your app, your tests and your libraries in ES6. You’ve gotten so used to the new syntax that it feels unnatural even trying to write ES5. And this makes it all the more jarring when you add a Gulp file with an import statement, and suddenly this happens:

(function (exports, require, module, __filename, __dirname) { import del from
SyntaxError: Unexpected reserved word

Oops, gulpfile.js only supports ES5. But lucky for you, teaching it ES6 is almost as simple as renaming a file. Almost…

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Testing in ES6 with Mocha and Babel 6

This guide is part of The Complete Guide to ES6 with Babel 6 series. If you’re having trouble upgrading to Babel 6, start with Six Things You Need To Know About Babel 6.

So you’ve written a useful little app with ES6, and being the excellent developer that you are, you want to test it. You’ve got some experience testing with Mocha, so you write a few tests and run them. And bam, nothing works. Why? Because by default, Mocha only knows ES5. But luckily, teaching Mocha ES6 only takes about a minute and 30 seconds!

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