renderX.js

export default class Card extends Component {
  constructor(props) {
      super(props);
  }
  
  renderHeader(headerProps) {
    if (!this.props.renderHeader) {
      return this.props.renderHeader(headerProps)
    }

    return <MyHeader ...headerProps />
  }

  // ...
  render(){
    return <View style={[styles.container]}>
      {this.renderHeader(this.props.headerProps)}

      // ...
    </View>
  }
}