React.addons is where we park some useful utilities for building React apps. These should be considered experimental but will eventually be rolled into core or a blessed utilities library:
TransitionGroup and CSSTransitionGroup, for dealing with animations and transitions that are usually not simple to implement, such as before a component's removal.LinkedStateMixin, to simplify the coordination between user's form input data and the component's state.classSet, for manipulating the DOM class string a bit more cleanly.TestUtils, simple helpers for writing test cases (unminified build only).cloneWithProps, to make shallow copies of React components and change their props.update, a helper function that makes dealing with immutable data in JavaScript easier.The add-ons below are in the development (unminified) version of React only:
PureRenderMixin, a performance booster under certain situations.Perf, for measuring performance and giving you hint where to optimize.To get the add-ons, use react-with-addons.js (and its minified counterpart) rather than the common react.js.
When using the react package from npm, just simply require('react/addons') instead of require('react') to get React with all of the addons.