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HTML

              
                <div id="app"></div>
              
            
!

CSS

              
                html, body {
  height: 100%;
}
              
            
!

JS

              
                /**

Component Expandable gets wrapped with HOC (withExpandable) to receive the props it needs

Pros:
 - Customisable
 - DRY

Cons:
 - HOCs aren't overly obvious/clear
 - Lack of enforced consistency (too customisable?)

**/

const withExpandable = (WrappedComponent) => class extends React.PureComponent {
  constructor(props) {
    super(props)
    this.state = {
      isOpen: false
    }
  }
  
  toggleOpen = () => {
    this.setState({ isOpen: !this.state.isOpen })
  }
  
  render() {
    return (
      <WrappedComponent 
        isOpen={this.state.isOpen} 
        toggleOpen={this.toggleOpen}
        {...this.props}
      >
        {this.props.children}
      </WrappedComponent>
    )
  }
}

const CustomExpandable = withExpandable(class extends React.Component {
  render() {
    const { isOpen, toggleOpen } = this.props
    return (
      <div>
        {/* NOTE: in here you'd likely recycle a few Expandable subcomponents, like Expandable.Header and Expandable.Content */}
        <button onClick={toggleOpen}>Click me</button>
        { isOpen && (
          <p>Hellooooooooooooooooooooooooooooooooooooooooooooooooooo</p>
        )}
      </div>
    )
  }
})

class App extends React.Component {
  render() {
    return (
      <CustomExpandable />
    )
  }
}

/** ========================================== **/

ReactDOM.render(
  <App />
  ,
  document.body
)
              
            
!
999px

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