infinite.jsx

class DateVerifier extends React.Component {
  constructor(props) {
    super(props)
    this.state = {
      dob: null
    }
  }
  
  render() {
    return (
      <DateInput onDateChange={(val) => this.setState({ dob: value })} />
    )
  }
}

class DateInput extends React.Component {
  constructor(props) {
    super(props)
    this.state = {
      day: null,
      month: null,
      year: null
    }
  }
  
  handleInputChange(event) {
    const target = event.target
    const name = target.name
    this.setState({
      [name]: target.value
    })
  }
  
  componentDidUpdate() {
    const date = moment([this.state.year, this.state.month, this.state.day]);
    this.props.onDateChange(date.format('MM-DD-YYYY'));
  }
  
  render() {
    return (
      <input name="day" onChange={this.handleInputChange.bind(this)} />
      <input name="month" onChange={this.handleInputChange.bind(this)} />
      <input name="year" onChange={this.handleInputChange.bind(this)} />
    ) 
  }
}