You are viewing the documentation for Blueriq 15. Documentation for other versions is available in our documentation directory.

This service call is part of the ongoing effort to support more DCM features natively in the Blueriq Runtime. Its signature and behavior may change over time. Please check release notes and upgrade instructions when using it.

This service call definition is part of the DCM library. It is only available when the case-engine-client profile is enabled.

With the DCM_ThrowMessageEvent service call, you can throw Message events towards the process engine. You can select a message event which you have previously defined in the process module. For every defined data field, you can define an expression to fill the field with information. The context of this expression is the module in which you place this service.

How the process engine behaves when receiving a message event is completely dependent on what was modeled in the process module. There is no default action executed when receiving a message event. Examples of behavior that you can model include: Starting a new case or making a task available to the worklist, canceling a case, or placing information in the domain of the case.


Parameters

NameDescriptionTypeRequired
Send to specific Case Ids

The id(s) of the receiving case(s). The specific caseId(s) do not have to be part of the message, but could be.

parameter valueresult
not specifiederror
invalid expressionerror
expression results in unknownerror
expression results in empty listnothing is sent
expression results in a list of case idsmessage is sent to the case ids in the list. Note that if one or more of the case ids does not exist, the service will take a fail exit called IdError. You have to map this on an event in your model.
Expressionfalse
Case Ids Target AttributeThe case ids of the case affected by the message event are placed in the selected attribute. This attribute must be multivalued and of the type integer.Multivalued integerfalse
Message eventThe name of the message event that will be triggered.Message eventtrue
ValuesThese elements represent the content of the message. You have to specify what the result attributes will be.Elementsfalse


DCM_ThrowMessageEvent vs DCM_ThrowAsyncMessageEvent

The DCM_ThrowAsyncMessageEvent is also available. As the name suggests, that service works asynchronously as opposed to this service which is synchronous. The benefit of using the asynchronous service is that a user does not have to wait for the message event to be processed, which could take some time if the message event is broadcast to a lot of cases. The downside of the asynchronous service is that you no longer receive the affected case ids, as you do not have to wait. So consider carefully which service you need for your use case. It's also possible to broadcast a message event to all listening cases using the DCM_ThrowAsyncMessageEvent, this is not possible using the synchronous service call.



When sending a message to a specific case it is not necessary to have a catching condition on the receiving message node.

A combination of a catching condition and specific case Id is possible. You can send a message to a select number of cases and still use the catching condition to decide to process the message or not.

If you have created a process and you want to extract its Id and save it in an aggregate then extract the value returned from the Case Ids Target Attribute. For example use the AQ_InstanceUpdate service to unpack the multivalued attribute by using an expression like this: UNPACK(Control.ProcessIds).

When sending a message that is used as an event to create a process, then only the new process is created. The event is not broadcasted to all other cases. So if you use an event as ProcessStartNode you should not reuse it as an Adhoc event or inline event inside processes.

Non-existing processess

When the message is sent to specific processes, and some of these do not exist any more, the service ends with a FAIL exit IdError. You have to map this exit to an event in your model in order to catch this. In this case, no processes will receive the message.

Inner workings

The service sends a request to the Case Engine which will in turn ask the Process Engine to which cases it should send the Message event. The case engine will then throw the Message Event to each case. It will add the affected cases to the Case Ids Target Attribute.

If an event fails to be processed, it will be added to the queue and handled asynchronously, the caseId will still be returned.