Chapter 12: Case Study: Knight s Tour

Overview

This chapter contains the third (and last) of the XSLT case studies. It shows how XSLT can be used to calculate a knight's tour of the chessboard, in which the knight visits every square without ever landing on the same square twice.

New features in XSLT 2.0 make this kind of application much easier to write, which means that the stylesheet is almost a total rewrite of the XSLT 1.0 version.

Readers of previous editions of this book have reacted differently to this case study. Some have suggested that I should be less frivolous, and stick to examples that involve the processing of invoices and purchase orders, and the formatting of product catalogs. Others have welcomed the example as light relief from the comparatively boring programming tasks they are asked to do in their day job. A third group have told me that this example is absolutely typical of the challenges they face in building real web sites. The web, after all, does not exist only (or even primarily) to oil the wheels of big business. It is also there to provide entertainment.

Whatever your feelings about the choice of problem, I hope that by showing that it can be done I will convince you that XSLT has the computational power and flexibility to tackle any XML formatting and transformation challenge, and that as you study it, you will discover ideas that you can use a wide range of tasks that are more typical of your own programming assignments.