Re: [xml-dev] Re: determining ID-ness in XML

[Elliotte Rusty Harold <elharo@metalab.unc.edu>]

At 2:54 PM +0000 10/31/01, Rob Lugt wrote:

>So, adding a new xmlid attribute has downsides either way:- you either need
>to update your DTDs or you need to update your xml processors.  This is true
>even for those people and applications that have no interest in being able
>to address ID-less elements.
>

Any time you add a new attribute, you have to update your DTDs. This is true of xml:id, xml:base, xml:space, and xml:lang. Nothing in this discussion changes that. Nothing is special about xml:id. 

However, we are not saying that every application has to use xml:id. Certainly not every application uses xml:space or xml:lang today, much less xml:base. If the XHTML folks don't want xml:id in their XHTML documents, they don't have to use it. They don't change their DTDs. In fact, they really don't need to change them because conformant XHTML documents already have a DTD, and do have ID type attributes.

Remember, the reason we're having this discussion is because not all XML documents have DTDs. It is precisely those without DTDs where xml:id is needed, and these applications can start using xml:id  immediately because they don't have a DTD to change! or even if they do, they don't require validity. 

-- 

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