Slidedeck from MidwestJS 2014 talk: Reconciling ReactJS as a View Layer Replacement

1. Reconciling React as a
View Layer Replacement
Zach Lendon
@zachlendon
#reactjs #midwestjs
#reactjsisawesome
https://github.com/zachlendon/midwestjs2014

2. Traditional JS
MV* “issues”
•“State”
•Performance
•Complexity
•Predictability
•Testability
• Isomorphic Javascript
• The right simple :: powerful ratio
• The right configurable :: opinionated
ratio
• Pluggable modular architecture
• Performant
• SEO
Top keys to future “web” MV*
framework success
“State” of the JS MV*

3. Meet React
•A Javascript Library for Creating User Interfaces
•https://github.com/facebook/react
•Open Sourced and Battle-tested by Facebook and
Instagram
•Browser support to IE8

4. “React is not a full MVC framework, and this is actually one of its
strengths. Many who adopt React choose to do so alongside their
favorite MVC framework, like Backbone. React has no opinions
about routing or syncing data, so you can easily use your favorite
tools to handle those aspects of your frontend application. You'll
often see React used to manage specific parts of an application's UI
and not others. React really shines, however, when you fully
embrace its strategies and make it the core of your application's
interface.”
@bkonkle: http://lincolnloop.com/blog/architecting-your-app-react-part-1/

5. Why React?
• “State” is what makes building UIs hard
• “Data Changing over time is the Root of All Evil”

6. React Solution
Use composable React components that effectively
re-render themselves on each state mutation

7. •Apple
•Oranges
•Apple
•Grapes
•Bananas
React
Before After

8. Virtual DOM
•In-memory representation of the DOM and
events system
•Even HTML5 events in IE8

9. Advantages of Virtual DOM
•Interacting with DOM -> Slow,
•with Javascript In-Memory Objects -> fast
•60 fps fast
•Faster parsing
•Faster Validation
•Since no real browser, can easily render on server or
client
•Easier To Test

10. Fallout Advantages of Virtual DOM include
•Autobinding
•Event Delegation

11. http://lincolnloop.com/blog/architecting-your-app-react-part-1/

12. React Components
React Components translate raw data into rich HTML
The Ultimate State Machine

13. React Components
React.createClass({..})
The Ultimate State Machine

14. Render: “pure” Javascript function
http://jsfiddle.net/zlendon/9xyn3/

15. Render: “pure” Coffeescript function
http://jsfiddle.net/zlendon/32xj5/

16. Render: Better “pure” Coffeescript function
http://jsfiddle.net/zlendon/32xj5/1/

17. Render: “JSX” Javascript function
http://jsfiddle.net/zH5YG/

18. JSX “Desugared” to native Javascript

19. Rules of Render
•Return a single child component
•Native DOM component
•Composite Component
•Return predictable result each time invoked
•Does not touch the DOM (read or write) or interact with the
browser (i.e., setTimeout)
!

20. Rules of Server Side Render
!
!
!
!
•renderComponentToString on server
•render on client, to same node, preserves server-rendered
markup and adds event handlers
•http://www.princeton.edu/~crmarsh/react-ssr/
(Charlie Marsh)
•https://github.com/andreypopp/react-async
•https://github.com/karlmikko/bleeding-edge-
sample-app/blob/react-router/server/render/
render.js (soon to be in React-Router)
tl&dr;

21. React Components: Input
•Props: immutable data specific to an instance of a
component
•Like params into a function
•State: Private mutable attribute. Change within
which trigger scheduling of a component re-render

22. Both Props and State
• Are plain JS objects
• Changes trigger a render update
• Are deterministic. If your Component generates different outputs for
the same combination of props and state then you're doing something
wrong.
https://github.com/uberVU/react-guide/blob/master/props-vs-state.md#readme

23. Rules of State
•Belong to only one component
•Within that component, modified 2 ways
•getInitialState
•setState
•Render returns same result each time invoked with same
state
•Do not use computed data or duplicate prop data as state
•Avoid using state when possible
•Do not change state of children components

24. Rules of Props
•Passed from the parent
•Immutable
•Often pass callback functions through them
!

25. Component Lifecycle
Mounting
• componentWillMount()
• componentDidMount()
!
Updating
• componentWillReceiveProps(object nextProps)
• boolean shouldComponentUpdate(object nextProps, object nextState)
• componentWillUpdate(object nextProps, object nextState)
• componentDidUpdate(object prevProps, object prevState)
!
Unmounting
• componentWillUnmount()

26. Mixins
•Cross cutting concerns
•Examples:
•ReactScriptLoader: https://github.com/yariv/ReactScriptLoader
•ReactIntlMixin: https://github.com/yahoo/react-intl
•Backbone.React.Component.mixin: https://github.com/
magalhas/backbone-react-component

27. Scaling React
!
!
!
!
Action Controller Model View
Conference MVC
• Modified from Flux into by Jing Chen at F8, 2014

28. Scaling with React
!
!
!
!
Action Controller Model View
Model
Model
Model
Model
Model
View
View
View
View
View
View
Real World MVC

29. Scaling with React
!
!
!
!
Action Dispatcher Store View
Action
Flux

30. Starting a New App: React
•Lots of Great “Full-Stack” Starter Kit Options - Many Listed:
https://github.com/facebook/react/wiki/Complementary-Tools

31. New Project w/ Routing
•React Boilerplate: https://github.com/rackt/react-boilerplate
•Uses:
•React-router (prev. react-nested-router)
•Translation of Ember Router API to React
•Webpack
•pushstate-serv

32. New Project w/o Routing
•https://github.com/newtriks/generator-react-webpack
•Yeoman Generator
•Uses:
•Webpack
•Grunt
•Karma

33. New Project w/ Routing & Server-side Rendering:
•React Quickstart:
•https://github.com/newtriks/generator-react-webpack
•Uses:
•react-router-component
•react-async
•express
•browserify
•npm

34. New Project: Midwest JS Demo
•React Boilerplate
•Plus:
•Express (3)
•Bootstrap 3

35. DEMO DISCUSSION

36. Adding React To Existing Project
“We don’t need to switch to React everywhere, all at once. It’s
not a framework that imposes anything on the application
structure. [...] Easy, iterative adoption is definitely something
in React’s favor for us.”
!
-Adobe Brackets Team

37. Backbone Views
•Nested Backbone.View’s are difficult to maintain
•Every collection change re-renders all views

38. Simple Backbone Port

39. Integration with Backbone Models and Collections
•Trigger React re-render on Backbone model “change” events

40. Mixins! Maybe
Lost shouldComponentUpdate hooks
TODO MVC: React + Backbone

41. Mixins! Maybe
Backbone-React-Component

42. Mixins! Maybe
Backbone-React-Component

43. Use State Callback

44. Use State Callback

45. Angular and React

46. Angular Directives Wrapping React
•ngReact
•ngReactGrid

47. Angular ngReactGrid Demo

48. Integration Lessons
•You can integrate React with other frameworks
•Backbone integration works better than many options since re-
rendering on model state change is the typical Backbone
approach
•Angular will work best from directives but is a bit of a force fit
•Best approach to let React own the DOM element being
rendered into

49. (Beyond the Obvious) Additional Resources (1/2)
•Great Collection of Community links:
https://github.com/mindreframer/reactjs-stuff
•Developing User Interfaces with React: http://youtu.be/
1OeXsL5mr4g?list=PLuE9Gq9Mxr5kCvVa7tcwW1S2-FEym5fbt
(intro + good performance demo)
•Good Flux intro by Ryan Florence: http://vimeo.com/
102953099
•Thorough and infamous Angular/ReactJS performance/
integration post: http://www.williambrownstreet.net/blog/
2014/04/faster-angularjs-rendering-angularjs-and-reactjs/
•Performance Tools: http://facebook.github.io/react/docs/
perf.html
!

50. (Beyond the Obvious) Additional Resources (2/2)
!
•Webpack Howto: https://github.com/petehunt/webpack-
howto
•Webpack Hot Module Replacement: https://github.com/
webpack/docs/wiki/hot-module-replacement-with-webpack
•Om: https://github.com/swannodette/om
•Jest: http://facebook.github.io/jest/

51. Thank You
Questions?
Zach Lendon
@zachlendon
#reactjs #midwestjs
https://github.com/zachlendon
#reactjs on freenode