React Native

Native App Development for Web Developers

Nader Dabit

@dabit3 on Twitter & Github

About Me

Software developer at SchoolStatus
Originally a web developer, now doing both web and mobile development
Transitioned from Angular > React + React Native in early 2015
Founder of Code South Labs
Author of React Native in Action from Manning Publications
Host of React Native Radio on Devchat.tv
Open source contributor to React Native and some React Native projects

What is React Native?

Framework for building Native Mobile Apps using JavaScript

Built on top of React
Use React Native to build cross platform mobile applications
Open sourced and maintained by Facebook
Apps written in JavaScript
Learn once, write anywhere
80%-95% code reuse
Compiles to real native mobile applications
Uses the same fundamental UI building blocks as real native apps under the hood

React Native vs HTML

<div>
  <p>Hello World</p>
</div>

<View>
  <Text>Hello World</Text>
</View>

HTML

React Native

React Native vs HTML

HTML | React Native

React Native vs React

import React from "react"

class SomeComponent extends React.Component {
  render () {
    return (
      <div>
        <p>Hello World</p>
      </div>
    )
  }
}

React

React Native vs React

import React from "react"
import { View, Text } from "react-native"

class SomeComponent extends React.Component {
  render () {
    return (
      <View>
        <Text>Hello World</Text>
      </View>
    )
  }
}

React Native

React Elements vs HTML

import { Button, SocialIcon } from "react-native-elements"

<Button
  title="Button" />

<SocialIcon
  type="facebook" />

React Native vs Hybrid

Pros

Project momentum
React ecosystem / Redux / one way data flow / Mobx
Better user experience - apps feel much better and smoother
No longer dealing with browser apis
Great developer experience
Hot reloading
Open Source
Core contributors of React Native are using it in their own production apps and in their companies
Fun to build once you learn the framework
Will be able to build for desktop, web, + other platforms
Continuous deployment easy to integrate (Code Push and similar)

React Native vs Hybrid

Cons

Still new - 18 months iOS / 12 months Android
Fairly Unstable - New versions every 2 weeks, some with breaking changes
Another technology that you have to learn (React), while Cordova can be picked up quickly by anyone who knows HTML + JavaScript.
Unfamiliar development environments and platforms (xCode, Android IDE)
Styling inconsistencies with CSS
Not yet quite to feature parity with Cordova

Is React Native Production Ready?

These people think so

Facebook Groups
Facebook Ads Manager
Facebook News Feed (currently being rewritten)
Discovery
CBS Interactive
Wix
Discord
Airbnb

Current Platforms

Can currently target Android, iOS and Windows

In development to target MacOS, Web, Apple TV, Tizen

Future / Developing Platforms

Compiles this:

React Native Web

<div>
  <span>Hello World</span>
</Div>

To this:

<View>
   <Text>Hello World</Text>
</View>

Fundamental changes in the way future engineered teams are designed and organized.

What this means

Organized by technology
iOS, Android, Web, Desktop teams
Expensive to build and maintain
Inconsistent APIs
Difficult to test across platforms
Virtually zero code reuse
Multiple languages, frameworks, and APIs

Traditional Engineering Teams

Organized by feature ownership
Single team working on Mobile, Web, and Desktop
Much less expensive to build and maintain applications across platforms
Consistent APIs
Less context switching
Large increase in code reuse
Single or smaller number of languages
Smaller number of frameworks
Possible consulting with native developers for complex feature implementations.
Nodejs backend ++

Engineering Team of the Future

(beta)

Cross stack engineering is an opportunity that is blossoming with React Native

- James Ide, Engineer at Exponent

Team × Technology React Conf 2016

Faster development time
Consistent apis
Can build for Web, Desktop, and Mobile
Was organized by platform, now by feature
Consistent user experience across platforms
Those familiar with native platforms will be especially valuable
Development is less expensive in terms of time and money
Cross Stack engineers more valuable, resulting in higher pay

Birth of the Cross Stack Engineer

(beta)

Growing opportunity in this space

Because Native development is becoming more and more expensive, engineers who can deliver applications across platforms and stacks will become extremely valuable and in demand.

Coming to React Native from the web

Dev environments / IDEs
Application UI
Routing
Styling inconsistencies vs CSS
Publishing apps to Play and App Store
Bridging native code (advanced dev)

Main stumbling blocks

Xcode (iOS)

Coming to React Native from the web

Routing / Navigation

Different paradigm than web routing
Navigation flows are hard to reproduce
Navigation UX is different each platform (managed by some navigation frameworks)

Routing / Navigation - React

Coming to React Native from the web

const App = () => (
  <Router>
    <Match exactly pattern="/" component={Home} />
    <Match pattern="/about" component={About} />
    <Match pattern="/topics" component={Topics} />
    <Miss component={NoMatch}/>
  </Router>
)

Routing / Navigation - Angular

$routeProvider
  .when("/", {
      templateUrl : "main.htm"
  })
  .when("/red", {
      templateUrl : "red.htm"
  })
  .when("/blue", {
      templateUrl : "blue.htm"
  });

Coming to React Native from the web

import React from "react"
import { Navigator } from "react-native"
import Component1 from "./Component1"

class App extends React.Component {

  renderScene (route, navigator) {
    return <route.component />
  }

  render () {
    return (
      <Navigator
        renderScene={this.renderScene}
        initialRoute={{
          component: Component1
        }} />
    )
  }

}

Routing / Navigation - React-Native

Coming to React Native from the web

Navigating between scenes - React-Native

Navigating between scenes web

<a href="/somepath">Click Me</a>

// import component
import Component2 from "./Component2"

// create navigation method
navigate () {
  navigator.push({ component: Component2 })
}

// handle click
<Button 
  title="Click Me"
  onPress={this.navigate}
/>

Coming to React Native from the web

navigator.push({
  component: Component2
})

Route array

[ {component: Component1} ]

Push route

Route array

[ {component: Component1}, {component: Component2} ]

navigator.pop()

Pop route

Route array

[ {component: Component1} ]

Coming to React Native from the web

navigator.push({ 
  component: Component2,
  name: 'NorthEast JavaScript Conference',
  location: 'Connecticut'
})

Rendering a scene

 renderScene (route, navigator) {
   if (route.location === 'Connecticut') {
     // do some logic, return different component
   }
   return <route.component title={route.name} />
 }

Everything is a property of the route

[ 
  {component: Component1},
  {component: Component2, location: 'Connecticut', name: 'NEJSConf'}
]

Route array

Coming to React Native from the web

Navigation - Getting Started

Explore different router Apis, choose one that makes sense to you

Coming to React Native from the web

Styling React Native

Uses JavaScript styling
Similar api, but not exactly, as css
Uses Flexbox for layout
Rely heavily on the documentation, especially at first

Styling React Native

// css
.header {
  width: 100%;
  background-color: red
}

// html
<div class="header" />

Web

// styles variable
styles = {
  header: {
    width '100%',
    backgroundColor: 'red'
  }
}

// style
<div style={styles.header} />

React

Styling React Native

// styles variable
styles = StyleSheet.create({
  header: {
    width '100%',
    backgroundColor: 'red'
  }
})

// style
<View style={styles.header} />

React Native

Styling React Native

Reusing styles in React Native vs Web

In web development, we reuse classes:

// css
.button {
  background-color: blue;
}

// html
<div>
  <button class='button'>Button1</button>
  <button class='button'>Button1</button>
  <button class='button'>Button1</button>
</div>

Styling React Native

Reusing styles in React Native vs Web

In React / React Native, we reuse components:

const Button = () => (
  <TouchableHighlight style={styles.button}>
    <Text style={styles.buttonText}>Hello World</Text>
  </TouchableHighlight>
)

export default Button

import Button from './Button'
import React from 'react'
import { View } from 'react-native'

class Home extends React.Component {
  render () {
    return (
      <View>
        <Button />
        <Button />
        <Button />
      </View>
    )
  }
}

Get a quick start by using UI Libraries, like bootstrap for the web.

React Elements

Get a quick start by using UI Libraries, like bootstrap for the web.

React Native Material Design

Get a quick start by using UI Libraries, like bootstrap for the web.

Shoutem UI

Tips when beginning React Native

99% of work can be accomplished from command line and any text editor
Rely on third party modules for basic styling and functionality if not 100% certain on implementation
Reach out to community for questions, a lot of helpful people out there
Possibly get started with Exponent