XSLT

Introduction

Extensible Stylesheet Language for Transformations (XSLT) is a programming language optimized for transformation. XSLT stylesheets are used by XSLT engines to transform one XML document into another document (html, pdf, doc, text, …). In the transformation process, according to instructions in XSLT, the XSLT engine selects content from the XML source, and places it in the output document.

Concepts

An XSLT engine takes two things as input:

o An XSLT stylesheet to govern the transformation process o An input document called the source tree. The output is called the result tree.

XSLT Engine

It reads in the XSLT stylesheet and caches it as a lookup table. For each node the engine processes, it will look in the table for the best matching rule to apply. The rule specifies what to output to build its part of the result tree and also how to continue processing. Starting from the root node, the engine finds rules, executes them, and continues until there are no more nodes in its context node set to work with. At that point, processing is complete and the XSLT engine outputs the result document.

How XSLT works:

xslt/html stylesheet—–>xslt engine—->html output ^ | | xml documents | | v xslt/xsl-fo stylesheet—–>xslt engine—->xsl-fo—->fo engine—–>pdf output