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On 14 Jul 2009, at 10:38 , Chuck Bearden wrote: > Is a namespace-aware XML processor permitted to drop a namespace > declaration when no elements or attributes in that namespace are > used within the scope of the declaration? Permitted by whom or what? Without that detail, no answer to this question is going to hold any water. The XML spec does not specify what information an XML parser must provide to a downstream application (with the exception of some quixotically detailed information about white space, which was the one thing that seemed non-obvious enough to merit specification). So a parser that silently drops all attributes with names containing an 'e' or with values containing the substring '42' is hard to convict of non-conformance, although it is easy to decide that you don't particularly want to use it. (You are right that a namespace-oblivious XML processor will treat namespace attributes as attributes -- in the XML grammar they *are* in fact attributes -- but wrong to believe that the spec requires that all attributes be 'retained'.) The XML Infoset spec (which some people expected to provide the missing normative statements about what a parser should tell the downstream app) also does not specify what information an XML parser must provide. So it may be hard to prove that my Perec/Adams parser fails to conform to the infoset spec, either; what the Infoset spec says is that what that parser provides is not the 'attributes' property of the element but something else. The namespaces spec does not, as far as I can see, forbid the dropping of random information, either (within limits). The XSLT 1.0 spec explicitly provides for dropping certain namespace nodes (and I cannot at first glance find any exception for namespaces that are actually used by the element on which the namespace node is excluded). Fortunately, the marketplace is by and large less forgiving on this subject than the specs. For the reasons mentioned by Ken Holman, and possibly just because it's easier to do it that way, all the widely used processors I know anything about will retain namespace nodes in the cases you describe. -- **************************************************************** * C. M. Sperberg-McQueen, Black Mesa Technologies LLC * http://www.blackmesatech.com * http://cmsmcq.com/mib * http://balisage.net ****************************************************************
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