gistfile1.js

import serializeForm from 'form-serialize'

const Something = React.createClass({
  getInitialState() {
    return {
      form: {}
    }
  },

  syncFormToState(event) {
    this.setState({
      form: serializeForm(event.target, { hash: true })
    })
  },

  render() {
    return (
      <form onChange={this.syncFormToState}>
        <input name="one"/>
        <input name="two"/>
        <input name="three[four]"/>
        <input name="three[five]"/>
      </form>
    )
  }
})