# Package org.zkoss.zk.ui.ext.render

- Interface Summary
  Interface | Description
  --- | ---
  Cropper | Implemented by the object returned by `ComponentCtrl.getExtraCtrl()` if not all of the children of a component are available at the client.
  DirectContent | Implemented by the object returned by `ComponentCtrl.getExtraCtrl()` if the component is able to generate the content directly.
  DynamicMedia | Implemented by the object returned by `ComponentCtrl.getExtraCtrl()`, if a component might have viewable parts other than HTML (WML, XAML or any client language).
  PrologAllowed | Implemented by the object returned by `ComponentCtrl.getExtraCtrl()` if it is able to generate the specified prolog before its real content.