/**
 * Copyright 2013-2014, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 *
* @providesModule ReactComponentWithPureRenderMixin
*/

"use strict";

var shallowEqual = require('shallowEqual');

/**
 * If your React component's render function is "pure", e.g. it will render the
 * same result given the same props and state, provide this Mixin for a
 * considerable performance boost.
 *
 * Most React components have pure render functions.
 *
 * Example:
 *
 *   var ReactComponentWithPureRenderMixin =
 *     require('ReactComponentWithPureRenderMixin');
 *   React.createClass({
 *     mixins: [ReactComponentWithPureRenderMixin],
 *
 *     render: function() {
 *       return <div className={this.props.className}>foo</div>;
 *     }
 *   });
 *
 * Note: This only checks shallow equality for props and state. If these contain
 * complex data structures this mixin may have false-negatives for deeper
 * differences. Only mixin to components which have simple props and state, or
 * use `forceUpdate()` when you know deep data structures have changed.
 */
var ReactComponentWithPureRenderMixin = {
  shouldComponentUpdate: function(nextProps, nextState) {
    return !shallowEqual(this.props, nextProps) ||
           !shallowEqual(this.state, nextState);
  }
};

module.exports = ReactComponentWithPureRenderMixin;
