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dataInputAssociation expressions

created by M Arnold in jBPM - View the full discussion

Hi,

 

I'm struggling to map input parameters to my task from process variables.  I can't find much documentation besides 5.8.1. Data, and the BPMN2 spec from OMG is cryptic.

 

I have a task something like this:

 

        <task id="_4" tns:taskName="Custom" name="sendCustom">

            <incoming>_2-_4</incoming>

            <outgoing>_4-_5</outgoing>

            <ioSpecification id="InputOutputSpecification_1">

                <dataInput id="_4_messageInInput" name="messageIn" />

                <dataOutput id="_4_messageOutOutput" name="messageOut" />

                <inputSet id="InputSet_1">

                    <dataInputRefs>_4_messageInInput</dataInputRefs>

                </inputSet>

                <outputSet id="OutputSet_1">

                    <dataOutputRefs>_4_messageOutOutput</dataOutputRefs>

                </outputSet>

            </ioSpecification>

            <dataInputAssociation id="DataInputAssociation_2">

                <sourceRef>event</sourceRef>

                <targetRef>_4_messageInInput</targetRef>

                <assignment id="Assignment_2">

                    <from xsi:type="tFormalExpression" id="FormalExpression_3">.</from>

                    <to xsi:type="tFormalExpression" id="FormalExpression_4">.</to>

                </assignment>

            </dataInputAssociation>

            <dataOutputAssociation id="DataOutputAssociation_1">

                <sourceRef>_4_messageOutOutput</sourceRef>

                <targetRef>resultMessage_4</targetRef>

            </dataOutputAssociation>

 

        </task>

 

Where 'event' is a process variable.  So what can I put in the <assignment><to> and <from>?  An XPath expression?  What if it's not XML?  When I can I use #{event}?  What are the valid values for from@xsi:type besides "tFormalExpression"?

 

When I execute this task as it is above, I get:

 

Caused by: java.lang.NullPointerException

        at org.jbpm.bpmn2.xpath.XPATHAssignmentAction.execute(XPATHAssignmentAction.java:91)

        at org.jbpm.workflow.instance.node.WorkItemNodeInstance.handleAssignment(WorkItemNodeInstance.java:193)

        ... 81 more

 

I'm sorry if this is a very basic or broad question.  I've scoured the web and really can't find many examples.

 

Thanks in advance for help.

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