React mixin to focus element with ref="firstInput"

focus-first-ref.js

const React = require('react');

module.exports = {

  componentDidMount() {
    this.focusFirstInput();
  },

  focusFirstInput() {
    const input = this.refs.firstInput; // <input ref="firstInput" />
    if (input) {
      React.findDOMNode(input).focus();
    }
  }

};