React help

component.jsx

import React from "react";
import cx from "classnames";
import _ from "underscore";
import I from "immutable";
import eq from "shallow-equals";

// Get refs to prop types
const
  {
    string,
    func,
    oneOf
  } = React.PropTypes;

class Field extends React.Component {
  constructor (props) {
    super(props);

    let
      data = new Field.State({
        value: props.initialValue
      });

    this.state = {
      data
    };
  }

  // State template
  static get State () {
    return I.Record({
      value: null
    });
  }

  shouldComponentUpdate (nextProps, nextState) {
    return !(
      I.is(nextState.data, this.state.data) &&
      eq(nextProps, this.props)
    );
  }

  render () {
    let
      {name, label, type, help, onUpdate} = this.props,
      {data} = this.state,
      value = data.get('value'),

      helpClass = cx({
        help: true
      });

    return (
      <div>
        <label htmlFor={ name }> { label } </label>
        <input
          type={ type }
          name={ name }
          value={ value }
          onBlur={ onUpdate }
          onChange={ this.handleChange }
        />
        <p className={ helpClass }> { help } </p>
      </div>
    );
  }

  handleChange (event) {
    let
      {value} = event.target,
      data = new Field.State({
        value
      });

    this.setState({ data });
  }
}

Field.propTypes = {
  type: oneOf(["text", "email"]),
  name: string.isRequired,
  initialValue: string,
  label: string,
  onUpdate: func,
  help: string
};

Field.defaultProps = {
  type: "text",
  initialValue: "",
  label: "",
  help: ""
};

export { Field };