[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] Canonicalized Schemas
Is it possible to transform an XML Schema into Canonical XML and still be able to use the Schema? It seems to me that it isn't, unless the application has some other kind of access to the namespace prefix-URI mappings that are discarded by Canonicalization (c14n). The prefixes will live on in the attribute values, but the prefix-URI mapping will disappear. This could suggest a few possibilities: 1) Canonical XML is not intended as a transfer format - the only reason it exists is to establish a common form that can be used in conjunction with digital signatures. While Canonical XML suggests a document syntax, that document syntax is only metaphorical, and not intended for actual transfer over the wire. 2) The Schema and c14n groups (and others, including XLink and perhaps XPath) need to have a discussion about what exactly 'namespace-aware' processing involves, and the role of prefixes within that processing. This could lead to some form of prefix preservation within c14n. 3) While XML document instances may be sent in canonical form, Schemas are a different type of information and should not be canonicalized. David Megginson made a convincing argument last week that schemas and style sheets deserve as much if not more security than documents - see http://www.megginson.com/ugly/ for the slides. To me, this suggests that signatures in particular and c14n as a part of that need to be addressed directly for schemas. I'd thought we'd seen the last of namespace implementation controversy, but I'm afraid it isn't quite over yet. Simon St.Laurent XML Elements of Style / XML: A Primer, 2nd Ed. Building XML Applications Inside XML DTDs: Scientific and Technical Cookies / Sharing Bandwidth http://www.simonstl.com *************************************************************************** This is xml-dev, the mailing list for XML developers. To unsubscribe, mailto:majordomo@x...&BODY=unsubscribe%20xml-dev List archives are available at http://xml.org/archives/xml-dev/ ***************************************************************************
|
PURCHASE STYLUS STUDIO ONLINE TODAY!Purchasing Stylus Studio from our online shop is Easy, Secure and Value Priced! Download The World's Best XML IDE!Accelerate XML development with our award-winning XML IDE - Download a free trial today! Subscribe in XML format
|