Issue 9247: No ReadParameterAction or WriteParameterAction (uml2-rtf)
Source: International Business Machines (Mr. Jim Amsden, jamsden(at)us.ibm.com)
Nature: Uncategorized Issue
Severity: 
Summary: One difference between UML activity and BPEL process is that all
data flows in UML must be explicit through connections between
activity parameter nodes, pins, central buffer nodes, and/or data
store nodes. UML activities can also have structural features and
variables which allow data to be passed between actions without
object flows, corresponding more like BPEL variable references.

However, input and output parameters have no such indirect access.
All actions that need information from parameters have to be
connected through object flows. This is inconsistent and can lead to
complex activity models because of the need for a large number of 
ForkNodes and ObjectFlows in order to access Activity parameters. 

UML2 should support actions to read and write parameters similar to 
reading and writing variables. The ActinInputPins can be used to 
simplify parameters in activities. 

Resolution: 
Revised Text: 
Actions taken:
January 18, 2006: received issue
Discussion: 

End of Annotations:=====
ubject: No ReadParameterAction or WriteParameterAction
X-Mailer: Lotus Notes Release 7.0 HF85 November 04, 2005
From: Jim Amsden <jamsden@us.ibm.com>
Date: Wed, 18 Jan 2006 15:53:26 -0500
X-MIMETrack: Serialize by Router on D03NM118/03/M/IBM(Release 7.0HF90 | November 16, 2005) at
 01/18/2006 13:53:38,
        Serialize complete at 01/18/2006 13:53:38




One difference between UML activity and BPEL process is that all
data flows in UML must be explicit through connections between
activity parameter nodes, pins, central buffer nodes, and/or data
store nodes. UML activities can also have structural features and
variables which allow data to be passed between actions without
object flows, corresponding more like BPEL variable references.

However, input and output parameters have no such indirect access.
All actions that need information from parameters have to be
connected through object flows. This is inconsistent and can lead to
complex activity models because of the need for a large number of 
ForkNodes and ObjectFlows in order to access Activity parameters. 

UML2 should support actions to read and write parameters similar to 
reading and writing variables. The ActinInputPins can be used to 
simplify parameters in activities. 


To: issues@omg.org
Cc: conrad.bock@nist.gov, Branislav Selic <bselic@ca.ibm.com>
Subject: No ReadParameterAction or WriteParameterAction
X-Mailer: Lotus Notes Release 7.0 HF85 November 04, 2005
From: Jim Amsden <jamsden@us.ibm.com>
Date: Tue, 28 Feb 2006 10:00:19 -0500
X-MIMETrack: Serialize by Router on D03NM118/03/M/IBM(Release 7.0.1HF1 | February 8, 2006) at
 02/28/2006 08:00:20,
        Serialize complete at 02/28/2006 08:00:20



(Note: this is an update to an already submitted issue, not a new issue) 

One difference between UML activity and BPEL process is that all
data flows in UML must be explicit through connections between
activity parameter nodes, pins, central buffer nodes, and/or data
store nodes. UML activities can also have structural features and
variables which allow data to be passed between actions without
object flows, corresponding more like BPEL variable references.

However, input and output parameters have no such indirect access.
All actions that need information from parameters have to be
connected through object flows to ActivityParameterNodes. This is inconsistent and can lead to
complex activity models because of the need for a large number of 
ForkNodes and ObjectFlows in order to access Activity parameters. 

UML2 should support ReadParameterAction and WriteParameterAction 
actions to read and write activity parameters similar to 
reading and writing variables and structural features. UML2 should also support OutputActionPin so output pins can directly reference parameters, variables and structural features without having to use explicit object flows. 

With these changes, reading and writing structural features, parameters, and/or variables for action inputs and outputs are all handled uniformely, and can be modeled using either push semantics using explicit object flows, or pull semantics using ActionInputPin and ActionOuputPin pins.