Front End London: Universal React

Transcript

1. Universal JavaScript
   

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2. @Jack_Franklin, Pusher
   

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7. Why?
   

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8. Source: GDS Blog, 2013
   

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9. "Surprisingly, the propor2on of people that have explicitly disabled
   JavaScript or use a browser that doesn't support JavaScript, only
   makes up a small slice of people that don't run JavaScript."
   

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10. "Progressive enhancement has never been about users who've
    turned JavaScript off, or least it wasn't for me."
    Jake Archibald, "Progressive Enhancement S:ll Important"
    

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11. Everyone has JS, right?
    • On a train / in a tunnel / etc
    • HTTP request hangs
    • Firewalls
    • ISP is interfering
    • A browser addon is messing with you
    • Your CDN is down
    Stuart Langridge's Flowchart
    

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13. Think about if this is right for you!
    

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14. Cu#ng Edge!
    We're really s*ll at the early stages of figuring out how this stuff
    works.
    Some of the code shown here isn't the easiest, or the APIs aren't
    that straight forward.
    This will change as we learn more. Don't expect this to be 100%
    smooth!
    

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15. React paved the way
    

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18. Code and demos: h,ps:/
    /github.com/jackfranklin/universal-react-
    talk/tree/fel
    

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19. A standard React app:
    class MyApp extends React.Component {
    render() { ... }
    }
    ReactDOM.render(
    ,
    document.getElementById('app')
    )
    

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20. Server side:
    class MyApp extends React.Component {
    render() { ... }
    }
    ReactDOM.renderToString()
    

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21. Tada!
    

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22. // some imports left out to save space
    import React from 'react';
    import MyApp from './component';
    import { renderToString } from 'react-dom/server';
    const app = express();
    app.get('*', (req, res) => {
    const markup = renderToString();
    res.render('index', { markup });
    });
    

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23. renderToString
    When your HTML is going to be picked up by React on the client
    renderToSta*cMarkup
    When your HTML is never going to be edited by client-side React
    

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24. 
    
    
    My App
    
    
    Hello from React
    
    
    

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25. Going Client side
    • Shared set of components that are environment agnos4c
    • A server rendering step (like we just saw)
    • A client rendering step
    • A bundler to generate our client side JavaScript
    

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26. Agnos&c Components
    

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27. Webpack
    

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28. Rendering on the Client
    

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29. Upda%ng our server template.
    
    
    
    
    
    
    

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30. Crea%ng client.js:
    import React from 'react';
    import ReactDOM from 'react-dom';
    import MyApp from './component';
    ReactDOM.render(
    ,
    document.getElementById('app')
    );
    

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31. Same Components on client and
    server
    

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32. npm install --save-dev webpack \
    babel-loader \
    babel-preset-es2015 \
    babel-preset-react \
    babel-yet-another-thing-lol-jk
    

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33. Create .babelrc
    {
    "presets": ["es2015", "react"]
    }
    

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34. Create webpack.config.js
    var path = require('path');
    module.exports = {
    entry: path.join(process.cwd(), 'client.js'),
    output: {
    path: './public/',
    filename: 'build.js'
    },
    module: {
    loaders: [
    {
    test: /.js$/,
    exclude: /node_modules/,
    loader: 'babel'
    }
    ]
    }
    }
    

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35. Run webpack:
    (PS: in produc.on we'd minify, etc!)
    > webpack
    Hash: 78c865d5593fe910f823
    Version: webpack 1.12.12
    Time: 4948ms
    Asset Size Chunks Chunk Names
    build.js 690 kB 0 [emitted] main
    + 160 hidden modules
    (Tip: webpack -w for con,nuous rebuilds)
    

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36. An interac*ve component
    export default class MyApp extends React.Component {
    constructor() {
    super();
    this.state = { count: 0 };
    }
    onClick() {
    this.setState({ count: this.state.count + 1 });
    }
    render() {
    return (
    
    Click Me
    Count: { this.state.count }
    
    );
    }
    }
    

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38. A read-only experience is way be3er
    than no experience.
    

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39. This isn't about giving every user
    100% func7onality every 7me.
    

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40. Rou$ng
    

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41. react-router
    The defacto, prac.cally standard rou.ng solu.on for React.
    h"ps:/
    /github.com/rackt/react-router
    

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42. First we need some more components, star1ng with components/
    app.js:
    import React from 'react';
    export default class AppComponent extends React.Component {
    render() {
    return (
    
    My web 2.0 app
    { this.props.children }
    
    );
    }
    }
    this.props.children are the nested routes.
    

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43. And then components/index.js:
    import React from 'react';
    export default class IndexComponent extends React.Component {
    render() {
    return (
    
    This is the index page
    
    );
    }
    }
    

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44. Define our routes:
    import { Route } from 'react-router';
    import React from 'react';
    import AppComponent from './components/app';
    import IndexComponent from './components/index';
    export const routes = (
    
    
    
    );
    

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45. Match against the URL on the server.
    Gets a bit hairy, s-ck with me!
    React Router server side guide
    

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46. // our newly defined routes
    import { routes } from './routes';
    // match is responsible for matching routes against a URL
    // RouterContext renders the components in the matched routes
    import { match, RouterContext } from 'react-router';
    

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47. app.get('*', (req, res) => {
    match({ routes, location: req.url }, (error, redirectLocation, renderProps) => {
    if (error) {
    res.status(500).send(error.message)
    } else if (redirectLocation) {
    res.redirect(302, redirectLocation.pathname + redirectLocation.search)
    } else if (renderProps) {
    res.render('index', {
    markup: renderToString()
    });
    } else {
    res.status(404).send('Not found')
    }
    })
    });
    

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48. Let's break that down...
    

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49. // take our app's routes, and the URL of the request
    match({ routes, location: req.url },
    (error, redirectLocation, renderProps) => {
    // error: given if something went wrong matching a route
    // redirectLocation: returned if the URL matches a redirect
    // renderProps: given if a route was matched and we can render
    ...
    });
    

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50. if (error) {
    // if there was an error, 500 with the error message
    // you might show a custom error HTML page here
    res.status(500).send(error.message)
    } else if (redirectLocation) {
    ...
    }
    

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51. ...
    } else if (redirectLocation) {
    // if we need to redirect, redirect to the new URL
    res.redirect(302, redirectLocation.pathname + redirectLocation.search)
    } else if (renderProps) {
    ...
    }
    

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52. ...
    } else if (renderProps) {
    // if we have renderProps that means we have a match and can render
    res.render('index', {
    // RouterContext is React Router's wrapper around our app
    // and renderProps contains all the info
    // React Router needs to render our app
    markup: renderToString()
    });
    } else {
    ...
    }
    

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53. } else {
    // if we get here, it's not an error, redirect or match
    // hence, 404!
    res.status(404).send('Not found')
    }
    

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55. Let's add an about page!
    

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56. components/about.js:
    import React from 'react';
    export default class AboutComponent extends React.Component {
    render() {
    return Rockstar developer;
    }
    }
    

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57. routes.js:
    import AppComponent from './components/app';
    import IndexComponent from './components/index';
    import AboutComponent from './components/about';
    import React from 'react';
    import { Route } from 'react-router';
    export const routes = (
    
    
    
    
    );
    

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58. And some links...
    ...
    render() {
    return (
    
    My web 2.0 app
    Home
    About
    { this.props.children }
    
    );
    }
    ...
    

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59. With no client side bundle, this works perfectly:
    

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60. Upda%ng the client side:
    import React from 'react';
    import ReactDOM from 'react-dom';
    import { Router, browserHistory } from 'react-router';
    import { routes } from './routes';
    ReactDOM.render(
    ,
    document.getElementById('app')
    )
    And then rerun webpack.
    

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62. Dealing with Data on the server and
    client
    

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63. (Caveat: this area is s-ll WIP)
    Lots of unknowns!
    

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64. 1. We want to be able to fetch data on the server and/or on the
    client.
    2. If the data is loaded on the server and rendered to the client, we
    ideally want to avoid making the request again.
    

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65. React Resolver
    

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66. code/with-react-resolver has an example.
    class IndexComponent extends React.Component {
    render() {
    return (
    
    This is the index page
    My github repo count: { this.props.github.public_repos }
    
    );
    }
    }
    export default resolve('github', (props) => {
    return fetch('https://api.github.com/users/jackfranklin').then((data) => {
    return data.json();
    });
    })(IndexComponent);
    

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67. Client:
    ...
    import { Resolver } from 'react-resolver';
    Resolver.render(() => {
    return
    }, document.getElementById('app'));
    

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68. Server:
    import { Resolver } from 'react-resolver';
    ...
    Resolver
    .resolve(() => )
    .then(({ Resolved, data }) => {
    res.render('index', {
    markup: renderToString(),
    data: JSON.stringify(data)
    });
    });
    

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69. Template:
    
    window.__REACT_RESOLVER_PAYLOAD__ = <%- data %>
    
    

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70. • Update the server side rendering to include
    window.__REACT_RESOLVER_PAYLOAD__.
    • Update the client side rendering to use React Resolver.
    • All data is resolved on the server, rendered and then used to
    populate data on the client.
    

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72. Code and Demos
    These slides and all the demos are on GitHub.
    jackfranklin/universal-react-talk
    Please send me ques,ons: @Jack_Franklin or jack@pusher.com.
    

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73. Universal JavaScript is here to stay.
    The techniques, libraries and approaches will change over 7me.
    There's plenty to figure out in this space!
    Long term I expect frameworks to do more, and it become even
    easier for developers to take advantage.
    

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74. Server side by default?
    

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75. Further Reading
    • Universal React on 24ways
    • How we built the new gocardless.com
    • GoCardless.com repo
    • Universal React Example app
    

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76. If you dig React
    I can make you dig it more! Day long React workshop in London:
    • 10 June
    

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77. Thanks! @Jack_Franklin
    javascriptplayground.com
    h"p:/
    /speakerdeck.com/jackfranklin
    jack@pusher.com
    

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