CountdownForm.jsx

var React = require('react');

var CountdownForm = React.createClass({
  onSubmit: function (e) {
    e.preventDefault();
    var strSeconds = this.refs.seconds.value;

    if (strSeconds.match(/^[0-9]*$/)) {
      this.refs.seconds.value = '';
      this.props.onSetCountdown(parseInt(strSeconds, 10));
    }
  },
  render: function () {
      return (
        <div>
          <form ref="form" onSubmit={this.onSubmit} className="countdown-form">
            <input type="text" ref="seconds" placeholder="Enter time in seconds"/>
            <button className="button expanded">Start</button>
          </form>
        </div>
      );
  }
});

module.exports = CountdownForm;