[This is preliminary documentation and subject to change.]
IBroadcastFilter::Delete is the method by which a filter is notified of an announcement deletion. Filters that schedule their data reception through Announcement Listener need not respond.
However, filters that schedule their own data reception should authenticate the deletion packet and, assuming it is valid, remove any self-scheduled data receipts that were initiated by the announcement being deleted. Such filters must maintain a list of the origin lines (for example, o=) and source addresses from any announcements received. When a deletion is presented to the filter, the filter must ascertain that the deletion pertains to some announcement to which it matched, and remove the scheduled receipt of the data from any queue the filter maintains.
Certain security verifications are required to ensure that an announcement deletion is legitimate. To locate more information on the relationship between an announcement and a deletion notice for that announcement, see Further Information on Data Services for the Client.
If a filter schedules tasks with Announcement Listener, then Announcement Listener provides all authentication.
HRESULT Delete(
IBroadcastAnnouncement *Announcement // pointer to the object
// containing the deletion
// announcement, as specified
// by SAP
);
Returns an HRESULT indicating success or failure.