Re: [jwt-dev] add unique ID to meta model?

[Christian Saad <christian.saad@xxxxxxxxxxxxxxxxxxxxxxxxxx>]

Hi Marc,

if I understand the request correctly, the requirement is to use 
completely transient IDs for identification purposes only inside the 
context of a specific model even to the point where the IDs will change 
every time the model is loaded (e.g. by calling EcoreUtil.generateUUID() 
in the ModelElementImpl constructor).

Regards,
Chris

Am 26.11.2010 15:26, schrieb Marc Dutoo:
> Hi
>
> I understand the need very well.
>
> However, I've seen that done in places (e.g. STP BPMN) and while it is
> very easy to do and use, it can be a mess to work with if you use these
> ids outside of the workflow model where they are defined, because they
> introduce strong coupling. In this latter case, it is better to use a
> **decoupled** way to refer to elements, typically a slashed path like we
> use in the TaskEngineFramework (1).
>
> So it depends whether you want to refer to it within the workflow model
> (then it's OK, they'd even be valid XML ids), or refer to it from
> another file (then a decoupled method that uses the workflow structure
> rather than arbitrary generated ids would be better, and preserve
> usability across different versions or forks of the same workflow model).
>
> Regards,
> Marc
>
> (1) see comment of modelElementPath in
> /jwt-taskengine-api/src/main/java/org/eclipse/jwt/runtime/taskengine/interfaces/ProcessModelService.java
> :
>
> /**
> * Returns the value of any action - task impl (application,
> hook...)-specific property.
> * @param modelName name of process
> * @param modelElementPath path of action - task tree (including within
> suprocesses),
> * consisting in their slash-prefixed names
> * @param propertyName
> * @return value with the right Java type (some low-end impls might only
> return strings)
> * @throws NoSuchModelElementException if can't find target action - task
> * @throws NoSuchPropertyException if can't find property on it
> */
> public Object getPropertyValue(String modelName, String
> modelElementPath, String propertyName)
> throws NoSuchModelElementException, NoSuchPropertyException;
>
>
>
> Le 25/11/2010 17:24, Christian Saad a écrit :
> > Hi all,
> >
> > my collegue Benjamin files a bug for including some kind of
> > identification mechanism for model elements in the form of a transient
> > ID attribute (see bug 329262). The requirement behind this is to make
> > each element of the loaded model uniquely identifiable so it can be
> > easily tracked.
> > Since this is probably a fairly unintrusive and easy to implement
> > change, I'd like to ask if you would be ok with this. Basically it
> > would boil down to adding an ID attribute to ModelElement which would
> > not be visible (e.g. in the property view) nor be serialized into the
> > workflow file.
> >
> > Please let me know what you think.
> >
> > Regards,
> > Chris
> > _______________________________________________
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> > jwt-dev@xxxxxxxxxxx
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>
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