[This is preliminary documentation and subject to change.]
An Enhancement control is an ActiveX control that can be embedded in enhancement pages to receive and respond to triggers.
When WebTV for Windows displays an interactive show, it tunes the Enhancement control to the Internet Protocol (IP) address and port specified in the enhancement data stored in the Guide database. (This enhancement data is stored as a result of a prior enhancement announcement.) The Enhancement control monitors this IP stream for triggers. When the control receives a trigger, it checks whether that trigger is defined by Broadcast Architecture or by a user.
The control handles Broadcast Architecture–defined triggers itself. For example, if a content provider transmits a Nav trigger, the Enhancement control causes WebTV for Windows to display new enhancement content. For each user-defined trigger, the control sends an event to its container Web page. Script embedded in that Web page can then handle the user-defined trigger event.
To locate more information about using the Enhancement control, see Further Information on Data Services for the Client.