Testing the DTDs and Schemas

[Don Day <dond@us.ibm.com>]

At last week's meeting, I raised the question of how to test the products of the DITA TC, both DTDs and Schemas. The main issue is to expose any indeterminate content models. I had a round with this particular bug in the "dita13" set of DTDs, and posted a correction to the documents area of this TC awhile back. But that bug is not revealed by all validators. One of the best methods for exposing such bugs seems to be to develop generated document instances with all possible permutations, and then to validate those instances with various tools. Still, this seems to be an incomplete method. For DTDs that others will be using and likewise deriving from, are there accepted public tools or methodologies that can give all DITA users a better level of assurance?

I believe the problem of indeterminate content models is less pronounced (or better behaved) for Schemas than it is for DTDs. In the case of DITA, the particular requirement is to confirm that both the DTDs and Schemas have fully closed declarations and that they are equivalent definitions. All this is compounded by the problem of representing the specialization design pattern in an equivalent way for both.

At IBM's alphaWorks, one can find XML Generator and XML TreeDiff as tools one might bring to bear on a test methodology. What else is freely available that we can bring to bear on testing? Perhaps the bigger question is whether certification is even necessary for a set of DTDs that have been in steady use for awhile?

Related to the question of testing DTDs, we also briefly discussed test suites of documents that might be devised to test compliance of tools/DTDs to particular behaviors. If this was indeed the gist of the brief discussion, now that I think about it, I'm not sure whether this would fit into the tasks for getting to the specification itself; perhaps this is a community activity that we engage in while the draft is in review for approval. Thoughts on document test suites and their role for DITA's marketing?

Testing activities like these are quite separate from things we might do (individually or as a TC) to encourage DITA's use by coaching and example, such as bona fide content examples from real uses of DITA, in which one might demonstrate anything from topic-oriented writing techniques to specialization methodology to creating override tools with specialized behaviors.

Regards,
--
Don Day <dond@us.ibm.com>
Chair, OASIS DITA Technical Committee
IBM Lead DITA Architect
11501 Burnet Rd., MS 9037D018, Austin TX 78758
Ph. 512-838-8550 (T/L 678-8550)

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