Hi,
See the comments inline.
Florian Lautenbacher ha scritto:
Hi Adrian, hi Andrea,
thanks for your helpful clarification about the metamodel of STP
IM. I now
had a closer look at the metamodel in your SVN and it is (in my
opinion)
much better designed than the one that is shown on your web site.
In fact
the core concepts are very similar to the core metamodel of JWT
(which can
be found on [1]). In STP IM you got a Process which contains *
Steps and *
Transitions. Each step has a name, a description, a number of
sourceTransitions and targetTransitions as well as several
observableAttributes. You also got ControlServices with subclasses
like
SplitControl or JoinControl. There can be normal Transitions or
TransitionsUnderCondition. And (nearly?) everything is a configurable
element.
Now looking at the JWT metamodel it is very much alike: here
everything is a
ModelElement. There are ActivityNodes which are connected via
ActivityEdges
(using source, target, in and out with same cardinality as
sourceTransitions, targetTransitions etc. in STP IM). There can be
several
types of ActivityNodes: one would be an Action (probably a Step in
IM) or it
could be a ControlNode such as a ForkNode or a JoinNode. An
ActivityEdge
might have a Guard (making it a "TransitionUnderCondition") whereas
the
Guard is specified in a GuardSpecification (with only a proprietary
notation
allowed).
Regarding your description of Properties and ObservableAttributes I
guess
that data that is necessary for execution (which might have been
added to
BPMN and shall be transformed into BPEL e.g.) is added as a
property to the
relevant step, am I right?
Yes.
For example for a Step that is configured with Service
[StartService] ServiceBinding [HTTP-InputBindingComponent] the
properties will be driven by the HTTP-InputBindingComponet, So the
step will have properties like:
URL:
isSoap:
and so on.
Quite different is the concept of relevant data:
Relevant data are extracted when the process is executed, evluating
expression on messages ( exchanged by endpoint in the case of Jbi )
or variable in the case of ( BPEL).
An example of relevant data is customerID extracted by /RECORD/
@customerId
Thanks for clarification about the owner attribute. Yes, I was more
thinking
about a participant or role than about an owner. Is this data (e.g.
which is
available in a swimlane or pool in BPMN) then added as a property
right now
to each Step?
As i say in previous post we'e not yet provided in the stp
intermediate model the concept of participiant role.
BTW i think that we could support this in BPMN editor in two ways:
1) Using the lane ( ant this will add some additional property on
the step, or better it will configure a particular
RolebAssignedStep, HumanTaskStep )
2) Get a view with a participiant list that we could drag anbd drop
on the activities
We cannot use the BPMN pool concept beacuse a pool in the im is
mapped in to a process.
I agree with Adrian and Marc that a first step would be having a
transformation from JWT to STP IM (and the other way round).
However, since
the metamodels are quite similar, this should not be so hard. Here
at JWT we
need to discuss who will be responsible for this task. Maybe
somebody of STP
might be able to assist us here!?
You're welcome. Ask what you want???
I am still wondering how you are planning to include the
information from
one metamodel in a way that it is clear in a next transformation
step where
it should go. So, if I specify the owner of a step in a pool or
lane in
BPMN, how is this information kept in STP IM so I can work with
that when
generating e.g. BPEL or XPDL-code? I guess you need some predefined
values
as properties that both model transformations use!? Or will there
be a
query language (such as RQL or SPARQL) where you can find the
"semantics" of
the property?
Best regards and looking forward to some more fruitful discussions,
Florian
Intermediate Model is a very generic model so you could have
situations where some properties ( for example
of the step ) will be important by code generator A and others will
be need by code generator B.
The concept is that IM bring you the information in a very generic
way, than is
responsibility of specific code generator to transform that
information in something executable.
To bring you an example, now i'm working in generating servicemix
service assembly applications from intermediate
model, and it's my codegenerator plugins that knows ( for example
how to organize service units, how to make cfg files
and so on .... ).
I don't know if it's clear, if you've some doubt please write me.
Regards
Andrea
[1] http://wiki.eclipse.org/images/2/2f/AgilPro_MetamodelDescription.pdf
-----Ursprüngliche Nachricht-----
Von: Andrea Zoppello [mailto:andrea.zoppello@xxxxxx] Gesendet:
Montag, 17. Dezember 2007 10:15
An: Florian Lautenbacher
Cc: Adrian Skehill; Adrian Mos
Betreff: Re: Current state of STP IM?
Hi,
Sorry for the late response but i'm just come back from Javapolis.
See comments inline
Adrian Skehill ha scritto:
Florian Lautenbacher wrote:
Hi,
I am wondering what the current state of the STP Intermediate
model is? Is the version on the Wiki [1] up to date?
I think version on the wiki is not updated. The version that we're
going to
commit will be the really the first version.
If so, I am curious why a step is part of a process, but the
transition is not?
And, on the other hand, why there is only one edge between a step
and a transition with cardinality *. In many other standards
(like UML activity diagrams) there are always two edges between a
node (=ActivityNode in UML) and a transition (=ActivityEdge in
UML) specifying that a transition has exactly two ends
(cardinality of 1 at each edge)?
In the version that we're going to commit a process will have a set
of steps
and a set of transitions. A transition wil have a source step and a
target
step then in the A step there will be two inverse relations a
relation
called sourceTransitions 1.* ( all transition for which the step is
a source
step ) and a realtion called targetTransition ( all transition for
whcih the
step is target )
How are the conditions at TransitionUnderCondition specified? Are
these boolean conditions connected with AND, OR, XOR and NOT? Or
is this open to each implementation (BPMN, SCA, JBI, etc.)?
The transition under condition will have a "Condition" ( Condition
abstract
entity ) where a condition could be an "ExpressionCondition" ( a
condition
expressed in some language Xpath, groovy, or a condition on header
properties "PropertyCondition".
Do only Transitions have ObservableAttributes? How about
attributes that are specified at a step?
In the actual version of the Intermediate Model we've introduced the
relation between Observable Attribute and Step ( 1..* each step
could have
one or more observable attribute ).
By the way what's important is to clarify the difference between
"ObservableAttribute" and "Property" of a Step.
Properties are information needed to configure the step in a
particular
runtime,and the properties set depends by ServiceBinding.
Observable attribute are data that will be extracted when the
process will
be executed to be visualuzed and monitored, by monitoring tools.
Does a process or a step has no owner, but only a service?
A process is a subclass of service so process could have owner.
What's important is to make distinct the concept of "Owner" from the
concept of "Participiant/Actor/Role" as we mean when we talk about
workflow
and in general process that require "human task".
At the moment we've not in the model the concept of "Particpiant/
Actor/Role"
for the support of worflow concept, but in the future we're going to
introduce something about.
Basically ( it's just an idea that we need to discuss with other
members
) we'll introduce the concept of role, and a subclass of Step
entity ( let
me say RoleAssignedStep or HumanTaskStep ) where we model the
relation
beteween a step and a role.
For "Owner" instead we mean the provider of a service ( process )
as it is
in service registry ( UDDI ) world.
But this part is not complete yet.
Looking forward to your answers,
Feel free to contact me if you need other information.
Florian Lautenbacher
-JWT project lead-
[1] http://wiki.eclipse.org/STP_Internal_Model_Discussion
Hi Florian,
Hi
Andrea Zoppello
--
*Andrea Zoppello*
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<www.spagoworld.org>
Spagic Architect
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Architect
Research & Innovation Division
*Engineering Ingegneria Informatica S.p.A.
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