[This is preliminary documentation and subject to change.]
The Broadcast Architecture supports a custom implementation of the ITaskTrigger interface of Internet Client that enables an application to create ambiguous task trigger objects. An ambiguous trigger is one where the date or time parameters, or both, are not known at the time of the trigger's creation. You can also use the Broadcast Architecture implementation of ITaskTrigger to create a trigger where the time and date are fully specified.
You can use ambiguous triggers to represent a range of shows. For example, if a show appears every weeknight at 7 p.m., you can create a date-ambiguous trigger that represents all episodes of the show. For information on how to do this, see Creating an Ambiguous Trigger.
Once an ambiguous trigger is created, it can be passed to either the ITelevisionServices::MakeLocalBroadcastSchedule or ITelevisionServices::MakeRemoteBroadcastSchedule method to create a show reference that represents multiple episodes. You can then schedule a show reminder for each episode by calling the IScheduledItems::Add method and passing this multiepisode show reference.
The Broadcast Architecture implementation of ITaskTrigger implements both the ITaskTrigger::SetTrigger and the ITaskTrigger::GetTrigger methods. These are functionally equivalent to the methods implemented by the Task Scheduler. They differ only in that they support ambiguous triggers.
However, the Broadcast Architecture implementation does not support the ITaskTrigger::GetTriggerString method. Calling this method produces an error.
To locate more information about ITaskTrigger, see Further Information on Television Services for the Client.