ReactJS findDOMNode and getDOMNode are not functions

Changed in latest React:

ReactDOM.findDOMNode

https://facebook.github.io/react/docs/top-level-api.html#reactdom.finddomnode

It is in the react-dom package. Note that ReactDOMServer has also been moved into another package. Probably in preparation for React related platform-specific APIs (such as React native).

To import/ require the package:

import ReactDOM from "react-dom";

or

 var ReactDOM = require('react-dom').