July 2004
Intermediate to advanced
479 pages
12h 30m
English
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Use RELAX NG and Schematron Together to Validate Business Rules
There are few issues regarding XML validation that cause as many headaches as validation of business rules (constraints on relations between element and attribute content in an XML document). This hack helps relieve that headache.
Even after the release of the new, grammar-based schema languages XML Schema and RELAX NG, it remains difficult to express restrictions on relations between the contents of various elements and attributes. This hack introduces a method that makes it possible to validate these kinds of rules by combining two XML Schema languages, RELAX NG (http://www.relaxng.org/) and Schematron (http://www.ascc.net/xml/resource/schematron/).
W3C XML Schema (http://www.w3.org/XML/Schema) lacks much support for co-occurrence constraints, and RELAX NG supports them only to the extent that the presence or absence of a particular element or attribute value changes the validation rules. On the other hand, Schematron provides good support for these types of constraints. Schematron is a rule-based language that uses path expressions instead of grammars to define what is allowed in an XML document. This means that instead of creating a grammar for an XML document, a Schematron schema makes assertions applied to a specific context within the document. If the assertion fails, a diagnostic message that is supplied by the author of the schema is displayed.
One drawback of Schematron is that, although the definition of ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.