title: `this.props` inside `getDefaultProps()` of React?
body: <p>I'm trying to add a prop that depends on other props that will be basically passed by the component's owner component.</p>
  
  <p>So I did:</p>
  
  <pre><code>propTypes: {
    user: React.PropTypes.object,
    comment: React.PropTypes.object
  },
  
  getDefaultProps: function() {
    return {
      admire: new Admire({
                user: this.props.user, 
                comment:this.props.comment
              })
    };
  }
  </code></pre>
  
  <p>But it seems like props <code>user</code> and <code>comment</code> are not accessible at <code>getDefaultProps</code> call time.</p>
  
  <p>Is there any way to define a default prop that depends on other props that will be passed from owner components?</p>