[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] Re: XML spec and XSD
Mukul Gandhi wrote: > I don't think, there is anything wrong with the basic core/philosophy > of XSD. I guess, some of users who don't like XSD generally, it's > probably because of it's huge size, and steep learning curve. > > I do. First, it does not encourage a schema-writer to make a user model, to know how to explain invalidity or versions/variants to humans. That information being missing from the chain, it entrenches the position of developers as gurus to whom the supplicant users must go to. In other words, XSD actively *discourages* validation and human inspection. The PSVI certainly may have enough information for automated data exchange in fully debugged, in blind accept/reject gateways, or data-mapped systems; but I don't know that was actually a use case which was not already served adequately (by ODBC, CVS, CORBA, IDL, now JSON.) In a decade where we supposedly appreciate Test-Driven Development more than ever before, we have a schema language that fights against this kind of use, in syntax, features, complexity and inexpressive autism. Second, it does not have enough hooks in it to allow traceability between the schema and business requirements. Look at the question of why one element is supposed to be followed by another. There are several possible reasons: 1) it might be the instrinsic or typical order for renderings, 2) by fixing an order, a schema-aware compressed form might save a bit (or is it half a bit?) - an entirely marginal reason to my way of thinking but I have heard it used, 3) because derivation by extension is being used in XSD 1.0 and so suffixation was the only possibility, 4) to mirror the order of some data which is transformed into this, 5) err no reason, it just seems neater XSD is not neutral about traceability: it is antagonistic to it. Now I agree that XSD 1.1 has lots of additional things which help mechanical power (at the expense of a multiplication of concepts): the open schemas idea and so on are things I (and, in particular, Roger Costello) have long raised, so I am sure many people will benefit from the XSD 1.1 changes (just as people benefit from lipstick on a pig?) But still some of them are hacks, bits tacked on (like the cart in the Imaginarium of Dr Parnassus) without addressing what I think are the more fundamental issues such as disconnection from humans and disconnection from requirements. You would expect that kind of disconnect in a technology invented in the 1970s or 1980s, but not one for leading us into the 2010s. So it is exactly in XSD's imagined core philosophy, detectable by how XSD has been used or implemented and where it thrived or failed, that I think the problem lies. XSD is not a technology that encourages technocrats to empower the just-folks or non-technical management, in the way that HTML, XML and, I really hope, Schematron do. That puts it in the class of being things that are part of the problem rather than part of the solution. Cheers Rick Jelliffe P.S. I don't know that this analogy will add to the clarity, so I have put it down here. Years ago there was a cartoon strip in the newspapers called Li'l Abner. It is rarely spoken of now, because of its depictions of US minorities, I gather. But there was a little animal called the Schmoo: in 1949 it was more popular than Mickey Mouse (see http://en.wikipedia.org/wiki/Shmoo For a pic see http://deniskitchen.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=BP_shmoopin ). It loves to be eaten (unlike the Magic Pudding, it gets used up.) The XSD standard is not a standard made by Schmoos. It centralizes the power of developers, rather than allowing developers to localize their role.
[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] |
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
|