Hi,
> This sounds realy great... Are these ebXML transactions specified in
> BPSS? I guess not it they are afterwards modeled in XPDL
No, they're specified in UML activity diagrams, and then transformed
into XPDL. We wanted to use UML because more people understand it, and
for the execution we wanted to use something near the implementation, so
XPDL seemed best.
> hmmm..... WFMOpen... I saw that a while ago. Don't know why I missed it
> now gave it a look again and since it is more standards based I'll
> definately go for this.
Yes, once I understood how it worked (I needed a little time here...),
it worked perfectly.
by the way, they also have a small XForms implementation, the "webform
tool". here's an interesting mail about it:
https://sourceforge.net/forum/message.php?msg_id=2394019
I had made a small comparative study of open source workflow engines a
few months ago. The workflow engines that seemed the most interesting
for our constraints were bonita (http://bonita.objectweb.org/), shark
(http://shark.enhydra.org) and WFMOpen.
> I'd like to have them tighter integrated and communicate via a
> messagebus (jms). It's indeed a good idea to not focus on integrating
> xforms as the internal webinterface of the wf tool but instead using an
> api to connect to is probably the better way to go.
Yes, but it also brings new constraints...in our case we already needed
decentralized installations of tomcat, so it wasn't a too big constraint.
> Jawe (from enhydra) as a modelling tool is probably also a good
> startingpoint. Or are you looking for higher level tools?
Yes, it's a very useful tool. But yes, we'll be looking gor higher level
tools for this other project, abandonning XPDL. I don't know much more
yet...
> All kinds of constraints that are possible in a scheme. Length, regexp,
> etc.... We have e.g. a schema where we've defined a 'licenceplate'
> element which has a regexp for the exact allowed format e.g.
> "[A-Z0-9]-[A-Z0-9]-[A-Z0-9]" I'd like these to be automagically used in
> the generated html page. This requires schema2xforms to detect those and
> pass them over into the xform (if that is possible) and then by adapting
> the xslt, and using some javascript library (already available here and
> resuable) have these checked on the client-side. I do not a a complete
> list yet. Maybe we should set up a wiki to have a more structured
> approach to this.
For the validation, shouldn't that be easy using Xerces? since most of
it is already supported.
> And these regular expression things (Chiba can currently not validate
> against a schema if i'm right). right... You do that separately after
> 'submission' by chiba?
Yes, I do it from the workflow engine, after the submission by chiba: I
simply do an XMLSchema validation with Xerces, so it includes all that
works in xerces...
Sophie
*Ronald van Kuijk <sf-Q7A9xK6HO3pWda1u4vU+3/P6llvjuJOh@xxxxxxxxxxxxxxxx>*
24/01/2004 00:57
To
sophie.ramel-bqDqoxiz9wg@xxxxxxxxxxxxxxxx
cc
Chiba-Developer
<chiba-developer-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@xxxxxxxxxxxxxxxx>
Subject
Re: [Chiba-developer] integation with BPM/WF engines
sophie.ramel-bqDqoxiz9wg@xxxxxxxxxxxxxxxx wrote:
>
> Hi,
>
> >> Did anyone try something like this before?
>
> Well, I'm working on a tool that can not directly be used for ebXML
> but that can be used to help validate models of ebXML transactions and
> messages: it's an "animator", that can animate a transaction modelled
> in UML, so that business experts can "play it" and see if the UML
> model corresponds to what they had in mind before it is really
> implemented.
> The first step is to transform UML models into XML files (UML class
> diagrams for messages -> XMLSchema and UML Activity diagrams -> XPDL
> file), and with these files to configure the animator (import the
> XMLSchema + other XML files in an XML database, import the process
> into our workflow engine).
This sounds realy great... Are these ebXML transactions specified in
BPSS? I guess not it they are afterwards modeled in XPDL
>
> The second step is the animation: the workflow engine (WFMOpen,
> http://wfmopen.sourceforge.net) executes the XPDL process, by sending
> web services to different "clients" (participants of the transaction),
> containing messages and XMLSchemas. Then the clients generate the
> XForms interface with chiba so that the user can fill it and send it
> back. The animator also validates all the messages it receives using
> other activities.
hmmm..... WFMOpen... I saw that a while ago. Don't know why I missed it
now gave it a look again and since it is more standards based I'll
definately go for this.
>
>
> It's not exactly the same since our XForms is only present on the
> "clients" (which are servers, btw) and the workflow engine
> communicates via web services, but it's not so different either...
I'd like to have them tighter integrated and communicate via a
messagebus (jms). It's indeed a good idea to not focus on integrating
xforms as the internal webinterface of the wf tool but instead using an
api to connect to is probably the better way to go.
> The animator is not packaged at the moment but it certainly should be
> shortly. The web page is http://efficient.citi.tudor.lu (oh wait, I've
> just seen that it doesn't work right now, and I'm not sure the guy
> maintaining it will have time to correct it until next week...try
> later perhaps!).
>
> > we haven't actually found time (and money ;) to do this but are highly
> > interested in any efforts in that direction. we have quite a bit of
> > the plan that would be needed in our heads and our distant vision is
> > to build such a platform:
> > you use graphical high-level tools (maybe SVG) to model your flows and
> > datastructures, build some xforms for manipulation of data and
> > implementation of use cases and get complete business apps without a
> > single line of coding and no knowledge of programming. - of course
> > it's still a vision but if you stumble about some adventurous
> > investors ... ;)
>
> That seems very interesting!
> We have a new project here that will start soon and that will be about
> building a BPM tool with only open source technologies (it's a project
> on open source methodology and software reuse methodology, the tool is
> only a case study). I had already though of something like this...and
> I have a colleague who programmed a SVG interface for a proprietary
> workflow engine that we had...perhaps he'll be able to adapt it to an
> open source engine like WFMOpen. Chiba would certainly be perfect to
> have a dynamically generated form UI.
Jawe (from enhydra) as a modelling tool is probably also a good
startingpoint. Or are you looking for higher level tools?
>
> > After that, maybe together with Sophie
> > Ramel, to refactor Schema2xforms so it uses xerces 2.6 and after that
> > extend it to take constraints from the schema into the xforms and have
> > an xsl that can do client-side validation...
>
> Good idea! I don't have a lot of time at the moment but it should be
> better in a few days/weeks.
> What kind of constraints did you have in mind?
All kinds of constraints that are possible in a scheme. Length, regexp,
etc.... We have e.g. a schema where we've defined a 'licenceplate'
element which has a regexp for the exact allowed format e.g.
"[A-Z0-9]-[A-Z0-9]-[A-Z0-9]" I'd like these to be automagically used in
the generated html page. This requires schema2xforms to detect those and
pass them over into the xform (if that is possible) and then by adapting
the xslt, and using some javascript library (already available here and
resuable) have these checked on the client-side. I do not a a complete
list yet. Maybe we should set up a wiki to have a more structured
approach to this.
> In the project that I presented at the beginning of this mail, we do
> constraint validation in the animator by adding verification
> activities in the workflow engine. We have 2 kinds of verification
> activities:
> - the first is simply to check that the XML message validates against
> its XMLSchema, but that is hardly a problem when chiba is used to
> write it (except for optional elements which can cause terrible
> problems, but this is another thread...)
And these regular expression things (Chiba can currently not validate
against a schema if i'm right). right... You do that separately after
'submission' by chiba?
> - the second is a "business rule" validation: the rules are written in
> a "nearly natural-language" as documentation on the UML model, using a
> tool called "Grammatical Framework": a colleague worked on this to
> translate such rules into an XML rules format called "Xlinkit"
> (http://www.xlinkit.com), which is sadly not open source anymore.
> At the beginning, we had our rules expressed in XPath (they were very
> limited: "message had a value X at a XPath Y", "previous message with
> value X at Xpath Y existed", "2 messages have the same values at XPath
> X", etc), and we also considered XSLT for a moment, but we decided it
> would be too complicated to translate natural language into XSLT and
> we chose xlinkit instead (it's a first order predicate language, so
> it's easier to use for rules).
>
These businessrule validations sound interesting, but I do not see me or
our company using something like this real soon. The businessrules we
have are are quite simple
> Sophie
>
>
> joern turner wrote:
>
> > Hello Ronald,
> >
> > Ronald van Kuijk wrote:
> >
> >> Hola,
> >>
> >> I was thinking of using chiba to create xml documents that can be
> >> send through an ebXML server. That is going to be fairly simple,
> >> since I've adapted the ebxml server to accept documents/messages
> >> through a jms queue and adapting chiba to have a JMSSubmissionHandler
> >> should not be to difficult.
> >>
> >> So I was thinking a little further. Separate xform documents will in
> >> many cases (at leas in mine) be part of a larger process. Some will
> >> be handled externally, hence the ebXML server and some internally. In
> >> all case, there is a kind of flow and tasklists involved. To me this
> >> sounds like BPM/WF. I'm looking into jBPM at the moment to see if it
> >> can fit my needs or be adapted.
> >
> > your not alone with this feeling ;)
> >
> Pheew, lucky me... again not alone
>
> > we discuss this idea for quite some time in different scenarios. it
> > does care how you name it: workflow, process-, bpm-engine... it should
> > be significantly easy to establish a thin layer above Chiba/XForms to
> > build complete applications with complex flow logic.
> >
> >>
> >> Did anyone try something like this before?
> >
> > we haven't actually found time (and money ;) to do this but are highly
> > interested in any efforts in that direction. we have quite a bit of
> > the plan that would be needed in our heads and our distant vision is
> > to build such a platform:
> > you use graphical high-level tools (maybe SVG) to model your flows and
> > datastructures, build some xforms for manipulation of data and
> > implementation of use cases and get complete business apps without a
> > single line of coding and no knowledge of programming. - of course
> > it's still a vision but if you stumble about some adventurous
> > investors ... ;)
> >
> The only thing I can donate at the moment is (my private) time (and I
> should spend some part of it writing a table-sort since I haven't had
> any response from brainjar.com) After that, maybe together with Sophie
> Ramel, to refactor Schema2xforms so it uses xerces 2.6 and after that
> extend it to take constraints from the schema into the xforms and have
> an xsl that can do client-side validation... only after that (wel maybe
> in parallel if my girlfriend doesn't start complaining) I'm looking to
> integration with jBPM. Which seems to be not to difficult. I've already
> advised those guys to have a look at chiba (see this thread:
> https://sourceforge.net/forum/message.php?msg_id=2387044) It looks like
> both projects can profit from one another.
>
> Well, now I think of it... maybe a (small?) financial donation would in
> place. Once I have convinced others in the company that we should use
> xforms I can also convince them to make a donation.
>
> >
> > Joern
> >
> >>
>
