[Zope3-dev] Re: WORKFLOW: Notes on WFMC and XPDL

[Peter Mayne]

Lennart Regebro wrote:
> 
> The YAWL language, being completely symbolic, lacks a standard digital 
> format for it (maybe I missed it), and the only editor there is the 
> reference one, ment to be used with the reference engine, which I don't 
> know if it is even possible to use in Zope3. That means that in worst 
> case, we have to reimplement the engine, and the editor, and in best 
> case, we have tied ourself to one editor.

There is an XML schema for the YAWL language. I wrote an Eclipse GEF 
plugin which does basic editing of XML workflow documents, but it would 
need more work, so the reference editor is probably the one to use.

The engine is written in Java. The previous version didn't have 
persistence, which is a bit of a problem for a workflow engine. I added 
it (using Hibernate) and gave the code to them, but I don't know if 
they've incorporated it into the latest version of the engine.

I used ZSI to write a Python SOAP client to my persistence-enabled 
version of the YAWL engine, but we probably wouldn't want a separate 
Java process.

Another possibility to ride on the coattails of might be jBPM. JBoss has 
picked it up, so it will probably get more popular.

Yet another: OpenWFE (written in Java again) provides Python and .NET 
access. From the web page: "An XPDL filter is under work: it will allow 
OpenWFE to interpret and use XPDL defined business processes." (I 
vaguely recall jBPM could read XPDL as well.)

When I looked at XPDL, JAWE, etc, my eyeballs collapsed from looking at 
the complexity.

It would be nice to be able to work with an existing workflow engine, 
and let other people do most of the work. :-) However, this conflicts 
with including the batteries in Zope.

PJDM
-- 
Peter Mayne
Spherion Technology Solutions
Canberra, ACT, Australia
"I'm after rebellion, I'll settle for lies" - Blue Oyster Cult