[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] Validating IDREFS...
When validating IDREF and IDREFS values for an attribute the following constraint is stated: Validity Constraint - IDREF Values of type IDREF must match the Name production, and values of type IDREFS must match the Names) production; each Name must match the value of an ID attribute on some element in the XML document; i.e. IDREF values must match the value of some ID attribute. Does this mean that you need to have the entire document parsed before you can make the check that the value of the ID matches the ID of some element in the document? If this is true, then for validating parser implementations you will first need to build an in memory parse tree using a non-validating parser and then validate the document by recursively traversing the parse tree. For large documents that wish to be validated, this seems like a major performance and memory problem, especially in memory hungry languages like Java. Besides this production, I cannot see any other production in the spec which prevents a validating parser from just validating the document from a stream (at least for the implementation I am working on). Perhaps this particular constraint should be relaxed so that this sort of validating can be done at a higher level as many application developers may want the benefits of validation without the obvious memory expense. I am not an SGML expert, so maybe someone here can give me some historical reason for why the XML spec needs to have ID's or at least ID's that have not previously been declared in the document when an IDREF is encountered. Thanx in advance, Tyler xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev@i... Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ To (un)subscribe, mailto:majordomo@i... the following message; (un)subscribe xml-dev To subscribe to the digests, mailto:majordomo@i... the following message; subscribe xml-dev-digest List coordinator, Henry Rzepa (mailto:rzepa@i...)
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