Simple React Context Example

simple-react-context.js

class App extends React.Component{
  render = () => <div className="app">{this.props.children}</div>
}
class Greeting extends React.Component{
  render = () => <p style={this.context.style}>Hello world!</p>
}
Greeting.contextTypes = {
  color: React.PropTypes.string,
  backgroundColor: React.PropTypes.string
}
class ThemeProvider extends React.Component{
  getChildContext = () => ({
    style : {
      color:'green', 
      backgroundColor:'black'
    }
  }),
  render = () => {this.props.chidren}
}
ThemeProvider.childContextTypes = {
  color: React.PropTypes.string,
  backgroundColor: React.PropTypes.string
}
reactDOM.render(
  <ThemeProvider>
    <App>
      <Greeting/>
    </App>
  </ThemeProvider>,
  document.getElementById('root')
)