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Trigger Event

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Revision as of 16:17, 14 December 2005 by Lmckenzi (talk | contribs)
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An Event which, when recorded or recognized by an application, indicates the need for an information flow to one or more other applications, resulting in one or more Interactions.

A trigger event is an explicit set of conditions that initiate the transfer of information between system components (Application Roles). The trigger event represents the “real-world” event such as the placing of a laboratory order or drug order. The trigger event must be systematically recognizable by an automated system.

The Trigger Event may be caused by one of the following:

  • Environmental - For example, the trigger event that prompts a system to send all accumulated data to a tracking system every 12 hours is considered Environmental. Similarly a user pressing a button in a user-interface would be considered environmental
  • State Transition - resulting from a state transition as depicted in the State Transition Model for a particular message interaction. The trigger for canceling a document, for example, may be considered a State Transition Based trigger event
  • Interaction Based - based on the receipt of another interaction. For example, the response to a query (which is an interaction) is an Interaction Based trigger event.

Most trigger events are State-Transition based and will be encountered when reading the dynamic message model information defined to support a particular message interaction. Some trigger events may be based on more than one state transition, which are assumed to occur simultaneously.

Trigger events which are either invoked by a state transition or which are associated with a state transition (as a request, fulfillment request or refusal) should include a link to the D-MIM definition of the class to be transitioned as well as the transition to occur (or which has occurred or was refused) for each associated transition.

Notes

  1. A Trigger Event (within a sending application) represents an event which happened at the sender's side of the communication link. The behaviour of a Receiver is exclusively linked to the interaction (in the form of its Receiver Responsibilities) or to attribute values within the message itself. Example: the Trigger Event "creation of a new Prescription" may result in a "fulfillment request interaction" as well as a "notification of the creation of a request interaction". The trigger event doesn't distinguish between the notification or the fulfillment request; this is accomplished at the interaction level.
  2. When defining a Trigger Event, it can't be used to negate or otherwise significantly alter the semantics of the static model being communicated. Example: if the focal act of the Domain Payload is in EVN mood, the Trigger Event (when used as a Receiver Responsibility) can't redefine the message to be an Order.
  3. Environmental trigger events may still be associated with a state transition. For example, a request to 'suspend' an Act would be triggered by an environmental trigger (e.g. a user clicking a button saying 'suspend'.