# com.bea.control
ExternalCallbackTarget Interface

public interface ExternalCallbackTarget

The ExternalCallbackTarget interface is a marker interface that should be placed on any control implementation (JCS) class that can be the target of an asynchronous external callback. An external callback is an event generated from outside the Workshop runtime. An example of this type of callback is an asynchronous callback on a web service proxy.
Declaring the interface indicates that the control expects to receive these events, and will also cause a top-level policy hook to be placed on any containing components so security for these callbacks can be configured.
Note: The ExternalCallbackTarget interface is part of the WebLogic Workshop Control Development Kit. The Control Development Kit is for users who are creating advanced controls. It is available in your BEA installation in the following directory: BEA_HOME\weblogic81\samples\workshop\ControlDevKit\