12:09 p.m.
M Arnold [https://community.jboss.org/people/marnold] created the discussion
"dataInputAssociation <assignment> expressions"
To view the discussion, visit: https://community.jboss.org/message/647913#647913
--------------------------------------------------------------
Hi,
I'm struggling to map input parameters to my task from process variables. I can't
find much documentation besides
http://docs.jboss.org/jbpm/v5.2/userguide/ch05.html#sec.data 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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10:03 p.m.
New subject: [jBPM] - Re: dataInputAssociation <assignment> expressions
Tihomir Surdilovic [https://community.jboss.org/people/tsurdilovic] created the
discussion
"Re: dataInputAssociation <assignment> expressions"
To view the discussion, visit: https://community.jboss.org/message/647993#647993
--------------------------------------------------------------
Your task specifies a data input "messageIn" and a data output
"messageOut". Let's say you have a process variable "event" as you
say specified, here are some scenarios to look at:
1) Simple data input mapping (lets say mapping process variable event to data input
messageIn):
<bpmn2:dataInputAssociation id="_fIGIxELFEeGV7InrpvHmpg">
<bpmn2:sourceRef>event</bpmn2:sourceRef>
<bpmn2:targetRef>_815293A1-6C79-403F-A469-55DD5991F788_messageInInput</bpmn2:targetRef>
</bpmn2:dataInputAssociation>
2) Doing an input assignment (lets say we want to assign data input messageIn a value
"hello"):
<bpmn2:dataInputAssociation id="_fIGIxULFEeGV7InrpvHmpg">
<bpmn2:targetRef>_815293A1-6C79-403F-A469-55DD5991F788_messageInInput</bpmn2:targetRef>
<bpmn2:assignment id="_fIGIxkLFEeGV7InrpvHmpg">
<bpmn2:from xsi:type="bpmn2:tFormalExpression"
id="_fIGIx0LFEeGV7InrpvHmpg">hello</bpmn2:from>
<bpmn2:to xsi:type="bpmn2:tFormalExpression"
id="_fIGIyELFEeGV7InrpvHmpg">_815293A1-6C79-403F-A469-55DD5991F788_messageInInput</bpmn2:to>
</bpmn2:assignment>
</bpmn2:dataInputAssociation>
3) Doing a data output association (lets say we want to map data output messageOut to the
process variable event):
<bpmn2:dataOutputAssociation id="_fVO9c0PkEeGI-ernV8JyGw">
<bpmn2:sourceRef>_3D204743-FBA0-497D-86C3-D1525E592376_messageOutOutput</bpmn2:sourceRef>
<bpmn2:targetRef>event</bpmn2:targetRef>
</bpmn2:dataOutputAssociation>
When you want to map process variables to data inputs of your task or map data outputs of
your task back to process variables you would use scenarios 1) and 3). If you want to set
a value to your data inputs (in jBPM for example that is used for the GroupId and TaskName
data inputs) you would use scenario 2).
Hope this helps.
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5:12 a.m.
New subject: [jBPM] - Re: dataInputAssociation <assignment> expressions
M Arnold [https://community.jboss.org/people/marnold] created the discussion
"Re: dataInputAssociation <assignment> expressions"
To view the discussion, visit: https://community.jboss.org/message/648153#648153
--------------------------------------------------------------
Thanks Tihomir, that helps a lot.
A couple of further questions would help me to get beyond the basics if you have the
time.
1. Supposing my process variable, event, is an XML document. Is it possible to create an
<assignment> that will use a XPath expression to select only a certain part of the
XML document (a single element's text value, say) and assign to a data input of my
task?
2. Supposing my process variable, event, is a Java object. Is it possible to create an
<assignment> that will use the result of a Java method of the object (e.g
event.getId()) and assign to a data input of my task?
Thanks
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5:19 a.m.
New subject: [jBPM] - Re: dataInputAssociation <assignment> expressions
Tihomir Surdilovic [https://community.jboss.org/people/tsurdilovic] created the
discussion
"Re: dataInputAssociation <assignment> expressions"
To view the discussion, visit: https://community.jboss.org/message/648155#648155
--------------------------------------------------------------
For both 1. and 2. the spec defines association transformation. For example you want to
associate process variable x.someParameter to your task data input xIn:
<bpmn2:dataInputAssociation id="_ta2cskLFEeGV7InrpvHmpg">
<bpmn2:sourceRef>x</bpmn2:sourceRef>
<bpmn2:targetRef>_815293A1-6C79-403F-A469-55DD5991F788_xInInput</bpmn2:targetRef>
<bpmn2:transformation xsi:type="bpmn2:tFormalExpression"
id="_ta2cs0LFEeGV7InrpvHmpg">x.someParameter</bpmn2:transformation>
</bpmn2:dataInputAssociation>
Even tho you can specify these type of transformations in the jBPM Web Designer easily (in
the assignment portion for example you would do "x.someParameter->xIn", you
would have to test this in the runtime. Alternatives would be for example to use
on-Entry/Exit scripts, script tasks, or if you are using domain-specific nodes you can do
any transformation in your executeWorkitem method with plain Java.
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Tihomir Surdilovic