A gentle introduction to XSLT

XSLT is a standard created by World Wide Web Consortium, designed for creating formatting structures that allow for the interpretation and modification of XML elements.eXtensible Stylesheet Language, or XSL was created similarly to XML. After submission to W3C and several working drafts, it was released in 2000. It’s goals are mainly similar with XML, more specifically aiming for a quick designing process, being transparent to users and developers, easy to use, with as few as possible optional features and being suitable for use over the Internet.

In 2001, XSL was split into four different standards by W3C: XSL Transformations (XSLT), XSL Formatting Objects (XSLFO) and Xpath, which is defining the linking structures and parts of documents.

As the vast majority of documents are created in a tree-like way, that is created from parent and children elements, XSLT allows you to create structures that allow the modifying and interpretation of the existing XML elements and output the original tree of elements to HTML or any other media. Also it allows you to transform a tree of XML elements into another modified tree of XML elements.

As XSLT documents  are based on XML, they must begin with the XML declaration and the XSL:stylesheet element, which is the most important part of the document and must contain at least the namespace declaration. Afterwards come the transformation rules that are added into the document as the child elements of the root element. The XSLT stylesheets are being created by using template rules that afterward create instances of fragments of the output tree. The result tree is made from a hierarchy of nodes that would after that be applied to the output XML document.

The XSLT proved to be a very efficient and easy way of working with XML and other XML-shaped documents, being of a great use to developers.