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The XML Recursion Language, XRL, is a declarative language that supports the modular composition of structured XML documents.

XRL is a very powerful "linked-data" language runtime that supports:

  • Reusable Widgets defined in separate XML documents,
  • XML templating, and
  • Structured XML document creation.

XRL may be used for regular XHTML web applications or for dynamic composition of arbitrary XML resources.

This tutorial provides a step-by-step guide which starts with address space mapping, introduces basic templating, examines push and pull widget design patterns, and ends with a demonstration of XRL as the foundation for an AJAX-style application.

Source Code

All of the examples developed in this tutorial are available as source code in the directory [ install ]/modules/urn.org.netkernel.tutorial.xrl-x.x.x/ - where "install" is the directory in which you installed NetKernel.

The best way to learn XRL is to play around so feel free to adapt and experiment with the code.

XRL Reference Guide

A fast-track to XRL and a reference guide for the syntax is provided here.