Re: [dita] Proposed Issue: Recognizing DITA Documents

[Eliot Kimber <ekimber@innodata-isogen.com>]

Paul Prescod wrote:
> That might be enough but I think that we could design something better.

The only other mechanism that seems likely would be some sort of 
PI-based declaration, but the W3C has a firm statement against the use 
of PIs in XML documents and I think we should respect that.

Thus, relying on namespaces is about all there is to work with. You 
cannot rely on a DOCTYPE declaration (because there probably won't be 
one) and you can't rely on a schemaLocation= attribute because there 
doesn't need to be one.

In XML, only namespaces provide an unambiguous, reliable way to 
distinguish the true type of a given element.

I specifically requested that all DITA-defined constructs require at 
least one namespaced attribute in a DITA-defined namespace so that 
general processors could reliably identify documents as containing 
DITA-based content. The ditaarch:DITAArchVersion attribute is the result 
of that request.

I could not think of any other way to do it, given the W3C prohibition 
against PIs.

> 1.	It's a little bit hard to find for computers because it isn't
> reliably on the root element (sometimes it is on a sub-element of the
> root element).

I don't think this is a compelling objection--it's easy enough to 
examine an entire document for the namespace declarations within it. It 
may be tedious but it's not hard. If anybody needs Java code to do this, 
I can provide it :-)

> 2.	It's hard to find for humans because it is not in the document
> instance but rather in the DTD or Schema.

It may or may not be in the document instance. One point of using 
namespaces for identification is that it allows DTD-less and schema-less 
documents to be reliably processed.

But I agree that this solution doesn't really help humans, but I'm not 
sure that's that big of an issue, for the simple reason that in most 
cases either you'll be using a software system which can tell you that 
it is or is not a DITA document or you simply know that you're in a DITA 
context. I think it will be the rare person who stumbles upon a bare XML 
document and needs to know whether or not it is in fact DITA-based and 
has no tools available to do it.

Of course we could easily implement and provide a "DITA recognizer" tool 
that would serve. Hmmm.

> 3.	The value seems to reflect the Open Toolkit version rather than
> the DITA Specification version.

If true, that needs to be fixed.

Cheers,

Eliot

-- 
W. Eliot Kimber
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