Costin Manolache wrote:
That's consistent with most of the current uses of XML namespaces - you
don't see users picking their favorite XHTML or XSLT namespace URI.

To elaborate on this: the original intention of namespaces was to provide universal names for elements. This means <a:section xmlns:a="http://www.w3.org/1999/xhtml";> is a XHTML section, which is diffferent from the docbook simplified section <a:section xmlns:a="http://oasis.org/docbook";> which is in turn different from every element with the local name "section" in any other namespace. Think of the namespace name (the URI, not the prefix) as part of the universal, galactic wide unique element name. (actual URIs for the samples above may differ).

I can add more - but I'm curious about the reverse, why would you consider
letting the users pick the namespace URI ?

Indeed, especially considered that the namespace prefix may already be arbitrarily choosen. Picking the namespace URI (more correctly: the namespace name) makes only sense if semantics other than identification is associated with it. The crowd over there at XML-DEV consistently argues against this. It may seem natural to use the namespace name to point to something (i.e. use it for location rather than identification), but the namespace spec authors recommended to use URIs for namespace names because URIs are the closest things to universal names we currently have, and not because there's something interesting at the other end. The problem is that everyone expects something different at the other end of the namespace: some want to point it to a schema for the vocabulary, some like to find an XHTML description, others prefer some sort of RSS metadescription, and on this list, surprise, an implementation class or a Jar seems to be a favorite.

J.Pietschmann




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