Presentation from meet.js meeting in Łódź on April 14th 2015.

1. Introduction to ReactJS

2. Introduction to ReactJS -
agenda
• What’s the fuss about React
• Where should I start
• Some coding
• Q&A

3. ReactJS is
Facebook’s
child
Mark Zuckerberg: Our
Biggest Mistake Was Betting
Too Much On HTML5 -
September 2012.
This was related to poor
performance at that time.

4. Features
• Virtual DOM
• JSX
• Server side rendering

5. Virtual dom - why React is so
quick
• Direct dom manipulation is
expensive and it’s possible to
do unnecessary manipulations
in transitional states
• React has it’s own tree and
after state changes it
calculates minimal and final
DOM modification
• You may even choose not
render some subtrees
selectively
(shouldComponentUpdate)

6. JSX - why new javascript
flavour?
• JSX makes html native part of
javascript
• For some mixing languages
makes it controversial
• Until you realise that you want
to separate concerns not
technologies
• It is not a new idea (QML,
MXML)

7. Getting started
• Pretty good resources from creators @ http://
facebook.github.io/react/
• Really good community @ http://
www.reddit.com/r/reactjs
• Several Yeoman generators

8. Wiring up
• runtime - JSXTransformer
• grunt-react
• gulp-react
• webpack
• browserify
• …

9. Let’s code

10. Seamless
• Swedish company with development moving
entirely to Łódź
• Currently developing SEQR - mobile payment
platform. This year we are rolling out to many
European countries and USA
• We are hiring: backend (fullstack) developers,
QA engineers,UX, mobile developers,
sysadmins

11. Q&A