Why?

• Develop twice
• Test twice
• Maintain twice
• Not reusable business logic
• Lengthy deployment

Why?

• Java - Android
• Objective-C / Swift - iOS
• Javascript - Web

Solution to our problems

REACT NATIVE

• "One language to rule them all"
• Utilizing native components
• 95% components same on both platforms
• Logic shared on all platforms

React

• Declarative
• Component-Based
• Learn Once, Write Anywhere

Declarative

Virtual DOM

Component

Learn Once, Write Anywhere

• Web
• Server Side
• Mobile
• Virtual Reality

React Native

Inline styles

Other "web standards"

• Flexbox
• XMLHttpRequest, Fetch API
• WebSockets
• Geolocation API
• setTimeout etc.

Native UI components

• View
• Text
• Image
• ScrollView etc.

Platform look&feel

Picker, RefreshControl, Switch, Slider, TextInput etc.

API

JS access to underlying features like app storage, clipboard, linking etc.

Platform specific API like DatePickerAndroid, ActionSheetIOS etc.

Native Modules

Under the hood

Async Bridge

• JS thread does not block UI thread
• UI diff is sent in a batch
• Translates to Apple UIKit / Android SDK views (no webview)
• Declarative animations

Development tools

• Hot reload
• Debugging JS in Chrome
• In-app inspector
• CodePush by MS
• Expo Snack
• Redux dev tools, ...

Other platforms

• Web
• Universal Windows Platform
• MacOS, Apple tvOS
• Ubuntu, Tizen?

Not so good

• Moving fast
• Variable quality of 3rd party
• Documentation coverage
• Not for action games development
• Slower app startup

Good

• Moving fast
• Active community
• Native speed & experience
• Code reuse
• React & JS
• Developer Experience
• Easy to start with

Declarative animations

• Composition (sequence, ...)
• Interpolation
• Native Driver