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Hi all, I'm pretty new to XML, but as I've poked around I've observed what seem to be some strange things. XML parsers all seem to provide interfaces which ignore the static structure information provided by DTDs and rely on "one fits all" interfaces to elements, in stark contrast to the conventions of statically typed languages. For instance, the first thing I played with in XML was SAX using Python. I was impressed by how easily it worked and how naturally it fit in with a dynamically typed language like python. Then I had a look at the Java interface and found that it was just the same, which I thought very odd! The natural mapping for SAX onto Java, to get the (significant) benefits of static typing, would be to generate a Visitor interface. The Visitor interface would have a method for "visiting" each type of element in the document, and the argument to this method would be an object which presents the element contents through typed accessor methods. At least, that's how it looks to me. In the case of DOM, again generating typed accessor code would provide these great benefits. People could use a DTD (or similar) as the definition language for their abstract data types, and generate DOM-compliant classes which they can both use "natively" in their language and also manipulate as part of a genuine DOM tree at the same time. It seem like these methods which ignore the wealth of static structure information available will begin to show serious problems if they try to scale to the features proposed in some specifications like SOX, where more fine grained relationships and constraints can be expressed. So, my question is: are there any efforts around working towards creating mappings from DTD or other other XML type definition languages to various programming languages (or to other IDLs like OMG's), or is there some reason why this is considered a bad idea? I'm excited by the possibility of using a visual modelling tool (perhaps using an extension of the UML) to model document structure, and from the model be able to generate a DTD, from which to generate classes which give me access to the XML data in a natural way for programming language. I'm amazed that more people don't seem to share this enthusiasm. What we're doing with vanilla DOM and SAX interfaces seems analogous to using CORBA IDL as documentation, and making all object calls using the dynamic invocation interface! P.S. I was told today that Oracle have recently done something similar to this, which sounds great. I look forward to taking a look, but I can't help but wonder if there's a reason that it took this long - and how much the Oracle product does. If someone could point me to some other products which do similar things, I'd be much obliged. Cheers, Luke 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/ and on CD-ROM/ISBN 981-02-3594-1 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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