Re: ocl conformance test



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From: Laurence Tratt (laurie@tratt.net)
Date: Fri 13 Feb 2004 - 16:24:30 GMT


On Thu, Feb 12, 2004 at 10:45:01AM +0100, Steffen Zschaler wrote:

[Jörn]
>> I agree, but your approach tacitly assumes that tools will be able to read
>> XMI-Files and (moreover) extract the statements from them. IMO this is
>> rather the exception than the rule.
> This seems to be putting the barrier pretty low. Any OCL tool will need to
> be able to access UML models in some manner. The two standard approaches
> would be either by accessing some kind of model repository or by reading in
> XMI files.In the latter case the ability to read in XMI files is implicitly
> given, while in the former case most UML repositories support filling the
> repository from an XMI file. So, I think its a pretty low barrier already
> to be able to read in XMI files.

That's certainly what would happen in an ideal world. About 18 months ago I
investigated a number of commercial and open source UML tools, as I was
writing an XMI exporter for a research tool we had at King's College. What I
found shocked me somewhat: I tried something like 7 or 8 tools. None of them
did what I would consider to be a good job. 2 or 3 generated XMI which
wouldn't even validate against the DTD, the most basic check there is. One
tool even managed to generate XMI which its own crummy importer couldn't
read back in.

Even for those tools which generated XMI valid against the DTD, pretty much
all of them violated other requirements not captured in the DTD. In the end,
the only standard there was that they could generate XMI which Rose could
read in [actually, there were a couple of situations when even this wasn't
true]. The XMI importers were mostly very poor, and for anything other than
a ridiculously simple model, the chances of exporting XMI from one tool and
importing into another were close to nil.

Part of the problem for this is that the XMI standard isn't a great one in
the first place and that worse there has been no checking that tools
actually conform to the standard in any way - people in the OMG are well
aware of these problems and the claim is that they will be fixed, presumably
at some point when UML 2 is finalized.

From Jörn's comment, I would assume that the position of 18 months ago still
holds roughly true today - that is that tools mostly operate in their own
little bubble with very, very limited practical interoperability with the
outside world.

Yours,


Laurie
-- 
http://tratt.net/laurie/

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