ReactDOM.unmountComponentAtNode boolean unmountComponentAtNode(DOMElement container) Remove a mounted React component from the DOM and clean up its event handlers and state. If no component was mounted in the container, calling this function does nothing. Returns true if a component was unmounted and false if there was no component to unmount.

Unmounting: componentWillUnmount void componentWillUnmount() Invoked immediately before a component is unmounted from the DOM. Perform any necessary cleanup in this method, such as invalidating timers or cleaning up any DOM elements that were created in componentDidMount.

by Pete Hunt React is, in my opinion, the premier way to build big, fast Web apps with JavaScript. It has scaled very well for us at Facebook and Instagram. One of the many great parts of React is how it makes you think about apps as you build them. In this post, I'll walk you through the thought process of building a searchable product data table using React. Start with a mock Imagine that we already have a JSON API and a mock from our designer. Our designer apparently isn't very good becaus

replaceState void replaceState( object nextState, [function callback] ) Like setState() but deletes any pre-existing state keys that are not in nextState. This method is not available on ES6 class components that extend React.Component. It may be removed entirely in a future version of React.

shallowCompare is a helper function to achieve the same functionality as PureRenderMixin while using ES6 classes with React. If your React component's render function is "pure" (in other words, it renders the same result given the same props and state), you can use this helper function for a performance boost in some cases. Example: var shallowCompare = require('react-addons-shallow-compare'); export class SampleComponent extends React.Component { shouldComponentUpdate(nextProps, nextState) {

ReactDOM.findDOMNode DOMElement findDOMNode(ReactComponent component) If this component has been mounted into the DOM, this returns the corresponding native browser DOM element. This method is useful for reading values out of the DOM, such as form field values and performing DOM measurements. In most cases, you can attach a ref to the DOM node and avoid using findDOMNode at all. When render returns null or false, findDOMNode returns null. findDOMNode() is an escape hatch used to access the

You've already learned how to display data with React. Now let's look at how to make our UIs interactive. A Simple Example var LikeButton = React.createClass({ getInitialState: function() { return {liked: false}; }, handleClick: function(event) { this.setState({liked: !this.state.liked}); }, render: function() { var text = this.state.liked ? 'like' : 'haven\'t liked'; return ( <p onClick={this.handleClick}> You {text} this. Click to toggle.

JSX is a JavaScript syntax extension that looks similar to XML. You can use a simple JSX syntactic transform with React. Why JSX? You don't have to use JSX with React. You can just use plain JS. However, we recommend using JSX because it is a concise and familiar syntax for defining tree structures with attributes. It's more familiar for casual developers such as designers. XML has the benefit of balanced opening and closing tags. This helps make large trees easier to read than function calls

React provides powerful abstractions that free you from touching the DOM directly in most cases, but sometimes you simply need to access the underlying API, perhaps to work with a third-party library or existing code. The Virtual DOM React is very fast because it never talks to the DOM directly. React maintains a fast in-memory representation of the DOM. render() methods actually return a description of the DOM, and React can compare this description with the in-memory representation to compu

Note: cloneWithProps is deprecated. Use React.cloneElement instead. In rare situations, you may want to create a copy of a React element with different props from those of the original element. One example is cloning the elements passed into this.props.children and rendering them with different props: var cloneWithProps = require('react-addons-clone-with-props'); var _makeBlue = function(element) { return cloneWithProps(element, {style: {color: 'blue'}}); }; var Blue = React.createClass({