MILAN 25-26 NOVEMBER 2016

{ Universal JS Web Applications with React

Luciano Mammino

WHo is LUCIANO?

nodejsdesignpatterns.com

lmammino

loige

loige.co

Agenda

  1. The term "Universal" JS
  2. Who & Why
  3. Common problems and technologies
  4. Building a frontend only Single Page App
  5. Making it universal

ISOMORPHIC

bit.ly/universaljs

UNIVERSAL WHAT?

not only

for the web...

  • Desktop applications
  • Mobile applications
  • Hardware

Advantages

of universal javascript

  • "JavaScript-only" development
  • Maintainability
  • Better SEO
  • Faster "perceived" load time

In the wild

it Looks great but...

Module Sharing

Use Node.js modules in the browser.

UMD

Universal Rendering

Render the views of the application from the server (first request) and then in the browser (next requests)

Universal ROUTING

Recognise the view associated to the current route from both the server and the browser.

Universal DATA RETRIEVAL

Access data (and APIs) from both the server and the browser.

AXIOS

UNIVERSAL

FETCH

Universal STATE MANAGEMENT

Manage changes on the state tree both on the server and the client...

Futuristic/ALTERNATIVE JS?!

OK...
LET'S Stop complaining and build something!

What tools are we going to use?

What are we going to build?

judo-heroes.herokuapp.com

bit.ly/judo-heroes-tutorial

curl -sS "https://judo-heroes.herokuapp.com/athlete/teddy-riner"

The data set

// src/data/athletes.js

const athletes = [
  {
    'id': 'driulis-gonzalez',
    'name': 'Driulis González',
    'country': {
      'id': 'cu',
      'name': 'Cuba',
      'icon': 'flag-cu.png',
    },
    'birth': '1973',
    'image': 'driulis-gonzalez.jpg',
    'cover': 'driulis-gonzalez-cover.jpg',
    'link': 'https://en.wikipedia.org/wiki/Driulis_González',
    'medals': [
      { 'year': '1992', 'type': 'B', 'city': 'Barcelona', 'event': 'Olympic Games', 'category': '-57kg' },
      { 'year': '1993', 'type': 'B', 'city': 'Hamilton', 'event': 'World Championships', 'category': '-57kg' },
      { 'year': '1995', 'type': 'G', 'city': 'Chiba', 'event': 'World Championships', 'category': '-57kg' },
      { 'year': '1995', 'type': 'G', 'city': 'Mar del Plata', 'event': 'Pan American Games', 'category': '-57kg' },
      { 'year': '1996', 'type': 'G', 'city': 'Atlanta', 'event': 'Olympic Games', 'category': '-57kg' },
      // ...
    ],
  },
  // ...
];

export default athletes;

React components

Layout component

// src/components/Layout.js

import React from 'react';
import { Link } from 'react-router';

const Layout = (props) => (
  <div className="app-container">
    <header>
      <Link to="/">
        <img className="logo" src="/img/logo-judo-heroes.png"/>
      </Link>
    </header>
    <div className="app-content">{props.children}</div>
    <footer>
      <p>
        This is a demo app to showcase 
        <strong>universal Javascript</strong>
        with <strong>React</strong> and 
        <strong>Express</strong>.
      </p>
    </footer>
  </div>
);

export default Layout;

IndexPage component

// src/components/IndexPage.js

import React from 'react';
import AthletePreview from './AthletePreview';
import athletes from '../data/athletes';

const IndexPage = (props) => (
  <div className="home">
    <div className="athletes-selector">
      {athletes.map(
        athleteData => <AthletePreview 
          key={athleteData.id}
          {...athleteData} />
      )}
    </div>
  </div>
);

export default IndexPage;

AthletePreview component

// src/components/AthletePreview.js

import React from 'react';
import { Link } from 'react-router';

const AthletePreview = (props) => (
  <Link to={`/athlete/${props.id}`}>
    <div className="athlete-preview">
      <img src={`img/${props.image}`}/>
      <h2 className="name">{props.name}</h2>
      <span className="medals-count">
        <img src="/img/medal.png"/> {props.medals.length}
      </span>
    </div>
  </Link>
);

export default AthletePreview;

AthletePage component

// src/components/AthletePage.js

import React from 'react';
import { Link } from 'react-router';
import NotFoundPage from './NotFoundPage';
import AthletesMenu from './AthletesMenu';
import Medal from './Medal';
import Flag from './Flag';
import athletes from '../data/athletes';

const AthletePage = (props) => {
  const id = props.params.id;
  const athlete = athletes.find((athlete) => athlete.id === id);
  if (!athlete) {
    return <NotFoundPage/>;
  }
  const headerStyle = { backgroundImage: `url(/img/${athlete.cover})` };
  return (
    <div className="athlete-full">
      <AthletesMenu/>
      <div className="athlete">
        <header style={headerStyle}/>
        <div className="picture-container">
          <img src={`/img/${athlete.image}`}/>
          <h2 className="name">{athlete.name}</h2>
        </div>
        <section className="description">
          Olympic medalist from <strong><Flag {...athlete.country} showName="true"/></strong>,
          born in {athlete.birth} (Find out more on <a href={athlete.link} target="_blank">Wikipedia</a>).
        </section>
        <section className="medals">
          <p>Winner of <strong>{athlete.medals.length}</strong> medals:</p>
          <ul>{
            athlete.medals.map((medal, i) => <Medal key={i} {...medal}/>)
          }</ul>
        </section>
      </div>
      <div className="navigateBack">
        <Link to="/">« Back to the index</Link>
      </div>
    </div>
  );
};

export default AthletePage;
// src/components/AthletePage.js

// ...

const AthletePage = (props) => {
  const id = props.params.id;
  const athlete = athletes.find((athlete) => athlete.id === id);
  if (!athlete) {
    return <NotFoundPage/>;
  }
  const headerStyle = { backgroundImage: `url(/img/${athlete.cover})` };
  return (
    <div className="athlete-full">
      <AthletesMenu/>
      <div className="athlete">
        <header style={headerStyle}/>
        <div className="picture-container">
          <img src={`/img/${athlete.image}`}/>
          <h2 className="name">{athlete.name}</h2>
        </div>
        
        // ...
// src/components/AthletePage.js


// ...


        <section className="description">
          Olympic medalist from 
            <strong><Flag {...athlete.country} showName="true"/></strong>,
            born in {athlete.birth}
            (Find out more on <a href={athlete.link} target="_blank">Wikipedia</a>).
        </section>
        <section className="medals">
          <p>Winner of <strong>{athlete.medals.length}</strong> medals:</p>
          <ul>{
            athlete.medals.map((medal, i) => <Medal key={i} {...medal}/>)
          }</ul>
        </section>
      </div>
      <div className="navigateBack">
        <Link to="/">« Back to the index</Link>
      </div>
    </div>
  );
};

export default AthletePage;

AthletesMenu component

// src/components/AthletesMenu.js

import React from 'react';
import { Link } from 'react-router';
import athletes from '../data/athletes';

const AthletesMenu = (props) => (
  <nav className="atheletes-menu">
    {athletes.map(athlete => {
      return <Link key={athlete.id} 
                   to={`/athlete/${athlete.id}`} 
                   activeClassName="active">
        {athlete.name}
      </Link>;
    })}
  </nav>
);

export default AthletesMenu;

Flag component

// src/components/Flag.js

import React from 'react';

const Flag = (props) => (
  <span className="flag">
    <img className="icon" 
         title={props.name}
         src={`/img/${props.icon}`}/>
    {props.showName && <span className="name"> {props.name}</span>}
  </span>
);

export default Flag;

Medal component

// src/components/Medal.js

import React from 'react';

const medalTypes = {
  'G': 'Gold',
  'S': 'Silver',
  'B': 'Bronze'
};

const Medal = (props) => (
  <li className="medal">
    <span className={`symbol symbol-${props.type}`}
      title={medalTypes[props.type]}>
        {props.type}
    </span>
    <span className="year">{props.year}</span>
    <span className="city"> {props.city}</span>
    <span className="event"> ({props.event})</span>
    <span className="category"> {props.category}</span>
  </li>
);

export default Medal;

NotFoundPage component

// src/components/NotFoundPage.js

import React from 'react';
import { Link } from 'react-router';

const NotFoundPage = (props) => (
  <div className="not-found">
    <h1>404</h1>
    <h2>Page not found!</h2>
    <p>
      <Link to="/">Go back to the main page</Link>
    </p>
  </div>
);

export default NotFoundPage;

ROUTING

2 routes

   Index Page:    /

Athlete Page:   /athlete/:id

// src/Routes.js

import React from 'react';
import { Route, IndexRoute } from 'react-router'
import Layout from './components/Layout';
import IndexPage from './components/IndexPage';
import AthletePage from './components/AthletePage';
import NotFoundPage from './components/NotFoundPage';

const routes = (
  <Route path="/" component={Layout}>
    <IndexRoute component={IndexPage}/>
    <Route path="athlete/:id" component={AthletePage}/>
    <Route path="*" component={NotFoundPage}/>
  </Route>
);

export default routes;
// src/components/AppRoutes.js

import React from 'react';
import { Router, hashHistory } from 'react-router';
import routes from '../Routes';

const AppRoutes = (props) => (
  <Router history={hashHistory}
    routes={routes}
    onUpdate={() => window.scrollTo(0, 0)}/>
);

export default AppRoutes;

Client APP

// src/app-client.js

import React from 'react';
import ReactDOM from 'react-dom';
import AppRoutes from './components/AppRoutes';

window.onload = () => {
  ReactDOM.render(<AppRoutes/>,
    document.getElementById('main'));
};

HTML WRAPPER

// src/static/index.html

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8" />
    <meta name="viewport"
          content="width=device-width, initial-scale=1.0">
    <title>Judo Heroes - A Universal JavaScript demo application 
      with React</title>
    <link rel="stylesheet" href="/css/style.css">
  </head>
  <body>
    <div id="main"></div>
    <script src="/js/bundle.js"></script>
  </body>
</html>

BUILD CONFIG

(BABEL + WEBPACK)

.babelrc

import webpack from 'webpack';
import path from 'path';

const config = {
  entry: { js: './src/app-client.js' },
  output: {
    path: path.join(__dirname, 'src', 'static', 'js'),
    filename: 'bundle.js'
  },
  module: {
    loaders: [{
      test: path.join(__dirname, 'src'),
      loaders: [{ loader: 'babel-loader' }]
    }]
  },
};

export default config;

.webpack.config.babel.js

{
  "presets": ["react", "es2015"]
}

Let's build it!

// src/server.js

import path from 'path';
import { Server } from 'http';
import Express from 'express';

const app = new Express();
const server = new Server(app);

// define the folder that will be used for static assets
app.use(Express.static(path.join(__dirname, 'static')));

// start the server
const port = process.env.PORT || 3000;
const env = process.env.NODE_ENV || 'production';
server.listen(port, err => {
  if (err) {
    return console.error(err);
  }
  console.info(`Server running on http://localhost:${port} [${env}]`);
});

Static Express server

Ready... LET's TEST IT

RECAP

What we learned so far

  1. Define views combining React components
  2. Add Routing using React Router
  3. Compiling our frontend bundle with Babel and Webpack
  4. Run the app with a static Express server

SERVER SIDE RENDERING AND ROUTING

Using browser history

// src/views/index.ejs

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8" />
    <meta name="viewport"
          content="width=device-width, initial-scale=1.0">
    <title>Judo Heroes - A Universal JavaScript demo application 
      with React</title>
    <link rel="stylesheet" href="/css/style.css">
  </head>
  <body>
    <div id="main"><%- markup -%></div>
    <script src="/js/bundle.js"></script>
  </body>
</html>

Converting static index.html into a template

Updating the server app

// ...
// universal routing and rendering
app.get('*', (req, res) => {
  match(
    { routes, location: req.url },
    (err, redirectLocation, renderProps) => {

      // in case of error display the error message
      if (err) {
        return res.status(500).send(err.message);
      }

      // in case of redirect propagate the redirect to the browser
      if (redirectLocation) {
        return res.redirect(302, redirectLocation.pathname + 
          redirectLocation.search);
      }

      // generate the React markup for the current route
      let markup;
      if (renderProps) {
        // if the current route matched we have renderProps
        markup = renderToString(<RouterContext {...renderProps}/>);
      } else {
        // otherwise we can render a 404 page
        markup = renderToString(<NotFoundPage/>);
        res.status(404);
      }

      // render the index template with the embedded React markup
      return res.render('index', { markup });
    }
  );
});

That's it!

LET's TEST again

RECAP

What we learned so far

  1. Create a Single Page Application with React and React Router
  2. Add server side routing and rendering using React and React Router libraries in out Express app

universal data retrieval

api-proxy & async-props

(COMPLETE CHAPTER in Node.js Design Patterns)

 

universal state management

Redux

Where do we go

from here...

Code: https://github.com/lmammino/judo-heroes-2

THANKS!

loige

loige.co

lmammino

(Special thanks to @cirpo, @andreaman87, Aleksandar Čambas & @quasi_modal)