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Re: [xml-dev] Compatibility for XML attribute types with schemas
- From: "Christopher R. Maden" <firstname.lastname@example.org>
- To: xml-dev <email@example.com>
- Date: Fri, 12 Oct 2001 22:39:54 -0700
At 11:48 12-10-2001, Elliotte Rusty Harold wrote:
>Most of the XML simple types in the W3C XML Schema Language -- e.g.
>NOTATION, NMTOKEN, iD, IDREF, etc. -- carry a compatibility rule; for example:
>For compatibility (see Terminology (§1.4)
><http://www.w3.org/TR/xmlschema-2/#terminology> ) *NMTOKEN* should be used
>only on attributes.
>How important is this? Would it really be a compatibility problem to say
>that an element must have type NMTOKEN? or be an ID? How would this be
>incomaptible with standard XML? The resulting document would still be
>well-formed and perhaps DTD valid. Nothing in the schema would change
>this. Of course, these constraints could not be used on elements in a DTD.
>However, netiher could a constraint that an element be required to contain
>an integer, whihc is acceptable in schemas.
I suspect (with no inside knowledge whatsoever) that it's more of a
deprecation. The only reason to use the XML 1.0-derived types is when
converting a DTD into XSDL (or creating XSDL from which a DTD will be
derived), in which case these types would only show up in attributes. I
suspect that when creating an XSDL from scratch, there will usually be a
more appropriate type than the XML 1.0 ones.
Christopher R. Maden, Principal Consultant, HMM Consulting Int'l, Inc.
DTDs/schemas - conversion - ebooks - publishing - Web - B2B - training
<URL: http://www.hmmci.com/ > <URL: http://crism.maden.org/consulting/ >
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