Cameron Laird's personal notes on XML Schema

XML Schema is a leading XML schema language. It generally stands between DTD and RNC in history, desirability, succinctness, and popular recognition. I prefer RNC ... Schematron goes off in a different direction.

XML Schema instances often bear an .xsd suffix.

I've learned plenty from Eric van der Vlist's book.

On-line introductions to XSD include:

• the W3C's Primer;
• Thanks to Gerald Lester for pointing out the Tutorial of the W3Schools, which hosts several other valuables ones [enumerate]. W3Schools organizes materials for handy reference, among other virtues;
• ZVON roughly matches W3Schools in style, with an even more strict focus on XML. Its XSD tutorial, written by Jiri Jirat, is ambitiously comprehensive, and includes considerable material on RNG;
• CodeGuru hosts a visually-appealing slighly Java-influenced tutorial by Simon Sprott that includes counsel on schema design (this same tutorial appears in nearly identical form at CodeProject and the Liquid site);
• XFront's tutorial involves a license agreement;
• I'm fond of XMLZoo;
• webucator sponsors this tutorial;
• RustemSoft's tutorial is particularly terse;
• ...
• Note also that several proprietary products for XML management include introductory material on XSD:
  • Doxygen
  • Liquid XML Studio

Validation: the W3C's online version of XSV went offline on the last day of June 2009. Now I use XML Me's online validator for schemata of moderate size. I also have a Windows executable that identifies itself variously as (installable) XSV31.EXE and "XSV 3.1-1". I haven't succeeded in getting useful results from it; like so many of the validators I've tried, it reports far too much is valid. How can that be, particularly when on-line XSV gave me such different results? I don't know, nor have I made time to find out. Apparently I'm using them the wrong way .. Henry Thompson wrote about XSV at the end of 2007.

I have an interest in Tcl-based validation. Richard Suchenwirth did nice partial work with tDom in 2004. TclDOM provides full validation ... [document]. I don't understand yet what tom does with tWSDL/TWiST; I need to give it more of a chance.

[Xerces2-J, JAXP, xjparse, Jing!, lxml, RS mini] [XSV: "c.xml catalog.xsd"] [XSV is only one that works for me.]

"The Importance of Being Valid" is a breezy introduction to RNC and XSD.