about processes and engines

Archive for the ‘oss’ Category

Boris goes to Barcelona

After Barcelona’s victory of yesterday (over the Gunners), Boris (Magnolia‘s strategist) decided he had to visit Barcelona, and he’ll do so to give a talk at TechTarget’s Java Symposium.

His blog post about the talk. (There’ll be a few words about OpenWFE, as it’s the workflow engine embedded within Magnolia 3.0).

Written by John Mettraux

May 18, 2006 at 9:35 pm

Posted in java, magnolia, openwfe, oss


Floyd Marinescu ‘unlaunched’ his new Uber-Community site : InfoQ.

Alexandru Popescu (aka “The Mindstorm“) is one of his fellow ‘unlaunchers’.

Alexandru being a Magnolia contributor/committer, no surprise, the site’s running on Magnolia CMS.
Scroll down their about page to learn more about Alexandru.

I’m looking forward seeing this site grow and publish quality content… Hey, there’s even a welcome goodie : a book named “Java Transaction Design Strategies” (available as a free PDF download), 188 pages on java transactions.

Congratulations to the InfoQ team !

Written by John Mettraux

May 18, 2006 at 3:40 pm

Posted in cms, dev, magnolia, oss

Lukas’ OpenWFE IDE

Lukas Eder, for his master thesis in Computer Science at the EPFL, is implementing an OpenWFE IDE, on the Eclipse RCP platform.

The requirements for the project weren’t specifying web or rich client, Lukas had to choose. He decided, having had previous experiences with Eclipse and its RCP system, to go the rich client way.
I must say I favoured a web based IDE for it’s so easy to deploy. But well, development should be fun, Lukas prefers it this way, let’s not restrain his creativity.

Basically, the IDE will allow to design/modify process definitions and edit the participant maps (and especially insert webservice participants within them).

I have to say that I’m pretty amazed at what he built so far.

OpenWFE IDE (1)These are two screenshots of the current status of his IDE.

There was already an Eclipse IDE implemented by Christelle and Helena (two other EPFL students), Lukas had to base his work upon it, but after a few days of reflection and analysis he decided to do in another way and to get information directly from OpenWFE process definition XSD (

OpenWFE IDE (2)We agreed that I should put the descriptions of the expressions directly within the XSD : structure and description placed outside of the IDE, what a nice trick ! The IDE will thus be always up to date , in synch with the latest development in the process definition language.

Of course, I’ve got to fill all the descriptions, but I’m quite happy to do that job (producing content for the IDE).

Another great thing about Lukas’ IDE is its bidirectional sync between the graphical representation of the flow and the process definition (XML) itself. You may say it’s not that hard, but Lukas managed to have a UI where you can select a piece of a process definition and the select occurs in both view (and in the outline as well).

We’re still discussing on how to map workitems (participants) to webservices, my intention for now, is to upgrade the current (simple and robust) WsInvoker to Xfire (1.1) (currently, it’s based on Axis). Lukas’ idea is to map directly within the webservice XML envelope. No firm decision has been taken yet.
Lukas already wrote a nice wizard for choosing webservices from UDDI servers.

Michael and I wanted this IDE to have simulation capabilities, well that’ll maybe be for the next iteration of that project. It’s not that hard to embed an engine within the IDE to simulate flows.

I asked Lukas to directly upload his source within OpenWFE’s subversion repository on In this way, it might be easier to find someone to maintain that code afterwards (if Lukas is not interested anymore).

Wrote enough for tonight.

Written by John Mettraux

May 16, 2006 at 9:11 pm

Posted in bpms, openwfe, oss, workflow

summer of code – fall of maintenance

It’s great to have students around, to boost your project. They’re fresh, they’ve got new ideas, they want to change the world. But that doesn’t imply they will stick after the project and maintain their code. Open source passion is not equally distributed and it comes in two flavours : passion for consuming open source and passion for consuming, building upon it and producing it.

What’s great about the ‘summer of code’ is that it links, under the auspices of a prestigious flag, young developers and open source communities.

In the end, most of the students will get back to their normal cursus and leave open source development to the real passionates among them (who probably are already working within some open source community).
Some [summer] code will remain and someone will have to maintain it.

Written by John Mettraux

May 16, 2006 at 5:12 am

Posted in blahblah, coding, oss


OpenWFE is number 2 on Sourceforge in activity.

When I logged in, I was surprised to see 100.00% of activity on the top right of the screen, number 6 ? Well, number 2. I like this digit, very Gemini.

number two

It’s hard to believe. What a nice surprise in the morning.

It currently doesn’t mean much, business as usual, the ‘Top Projects‘ page on is stuck with the same rankings since at least 3 weeks, where OpenWFE is a happy #12.

This ranking reflects the hard work behind OpenWFE.
It’s not over : this summer will be very productive, summer of code.

Written by John Mettraux

May 12, 2006 at 5:23 am

Posted in dev, openwfe, oss, workflow

one seven zero… b

I just had to release 1.7.0b.

Unfortunately I had tested 1.7.0pre6 instead of 1.7.0[pre10] on my windows platform (VMWare). Denis Delangle was kind enough to fill a bug report.

Java couldn’t canonalize a path ending with “*” on Windows, a few lines of code and it was OK.

Lots of people downloaded this buggy 1.7.0… That’s bad luck.

Many thanks to Denis.

Written by John Mettraux

May 10, 2006 at 6:27 pm

Posted in dev, openwfe, oss [anonymous] forums

It’s over. It’s been six years since I’ve set up my first project on This week, I had my first two spam posts on OpenWFE help forum.

I had kept it open for ‘anonymous’ posters (nobody), but now after only two spam posts (in only one week), I decided to close it, allowing only users to post on it.

I can’t lose time at deleting/excluding such messages every day. Sorry, John Doe, you’ll have to set up an account.
The second version of the OpenWFE website (first move to Confluence) fell regularly victim to wiki spam and other trolls. I don’t want to clean out such cruft day after day (especially in the unfriendly admin interfaces).

Breaking news : Magnolia 3.0, the content management suite, will be released on Thursday. It embeds OpenWFE as its workflow engine. It’s not only a [web] content management suite, but also a complete document management system.

Written by John Mettraux

May 9, 2006 at 9:18 pm

Posted in blahblah, magnolia, oss, workflow


I finally implemented it. The <cancel-process> that everybody wanted. Explicit termination of a process instance.

        <participant ref="role-alpha" />
        <cancel-process />
        <participant ref="role-bravo" />
        <participant ref="role-charly" />

Bravo and Charly won’t never see a workitem coming from that version of this process definition.

The next step will perphaps be a mechanism for cancelling expressions explicitely from the definition. I currently think it’s a bit too low level and that there are already mechanisms in OpenWFE for handling that, especially as shown in the Workflow Patterns (BTW, the real site for workflow patterns is here).
I’ll explain this <cancel-expression> idea in a later post (and with more details).

I’ve also uploaded a new version of the OpenWFE process definition schema, it’s at

Maybe OpenWFE 1.7.0 will be released tomorrow.

Written by John Mettraux

May 8, 2006 at 9:07 pm

Posted in bpms, openwfe, oss, workflow

help from the forums

I have been a newbie, I will be a newbie. I behaved like a complete newbie, I hope I will never behave like a complete newbie again, just like a regular newbie.
Silence and/or acid replies shaped me out of the ‘complete newbie’ status.

On my project web site, there is this page named “Important Reads“. I redirect people on the forums there from time to time.
On which occasion do I do that ? When I feel that it’s a waste of time trying to explain anything to the person requesting help on the forum.

I love to play go, when a group of stone is dead, don’t waste energy (moves / stones) on it.

Gmane also put up a nice page : “Contacting Gmane“, I’ll take inspiration from it to enhance my “Forums and List” page.

There are people wasting other’s people time on these forums. Sometimes I think, hey, he took the time to evaluate my software, he deserves some help… some help, not unlimited help.
It’s free and open source software, it’s somehow easier to evaluate than closed source software (or anything that you might dub as ‘community edition’ and fill forms to download / join the ‘community’).

This is just blahblah, I’d better get back blogging about workflow and other bpm niceties.

Ah, just a link before vanishing : “Everyone wants to ‘own’ your PC” by Bruce Schneier. I really like the conclusion of this (short) article.

Written by John Mettraux

May 5, 2006 at 3:32 pm

Posted in blahblah, oss

maven2 upload

As OpenWFE got integrated within Magnolia, availability through Maven became a must.

I found this little neat site mashing up the maven repository so that you can browse it (of course they add some google ads on top of that). The page about OpenWFE uploads will show you the 1.7.0pre4 and 1.7.0pre9 I uploaded.

I have to say I haven’t converted OpenWFE to be Maven buildable. I’m happy with Ant, I just need a make-like tool. Of course I know that you can do pretty neat things with Maven, but I currently want my build tool to stay a tool and I don’t want to invest time in forcing my codebase into a set of constraints.
But of course, I’m closely watching people around me using Maven and pondering how they benefit from it.

Written by John Mettraux

May 4, 2006 at 10:47 am

Posted in cms, dev, openwfe, oss