Built-in template rules and how to override them David J. Birnbaum Introduction to XSLT for Digital Humanities, DHSI, 04-08 June 2012 Women Writers Project (via website)
url:mailto:wwp@northeastern.edu

Copyright 2011 David J. Birnbaum and the Women Writers Project

This TEI-encoded XML file is available under the terms of the Creative Commons Attribution-ShareAlike 3.0 (Unported) license.

 Providence, RI USA

XSLT built-in template rules

 Per request DJB, put wrapper element around wombat example output -- untested Reformatted some of the CDATA sections to add indenting to tags.
What’s built in? Where do we start? at the document node (itself the parent of the root element) What happens when there is no applicable template rule? The built-in defaults are applied. Kay, 79 What happens where there is exactly one applicable template rule? Er ... it gets applied. What happens when more than one template rule would seem to apply? Built-in priority Kay, 686 User-specified priority Kay, 483
Launching a transformation

Processing starts at the document node, which sits above the root element (the top-level element that contains all other nodes)

In a TEI document, the root element is normally TEI

Built-in template rules will walk the tree and process the entire document (see below)

Override the built-in rules by specifying your own to: Perform non-built-in processing Cause items not to be processed

Built-in template rules Element: process children (elements and text nodes), applying applicable template rules (built-in or specified) Attribute: do nothing (no output) Text: output string value Kay 79
Priority

Built-in priority: the rule with the most specific match is applied
User-specified priority Built-in priorities range from 0 to 0.5 User-specified priorities may be any number (including negative)
Overriding a template rule The built-in rule for any element is to process its child elements and text nodes. The built-in rule for the document node would process its single root element. In the case of a TEI document, that’s usually the single TEI node. In the example above, instead you grab all head elements everywhere. No other nodes are processed unless they’re inside a head.
How to use built-in template rules

Should you write rules that duplicate the built-in?

Yes if you like to be reminded of what happens with every node. No if you find a briefer stylesheet more legible. The preceding stylesheet will apply built-in templates to everything except to head elements For head elements in the input it will create wombat elements in the output. The contents of the original head elements will be processed according to the built-in template rules, with the output inserted into the new wombat element. (The result, BTW, is typically not well-formed XML — why not?)
Built-in templates and the wombat

djb_wombat.xml

The koala is also known as the marsupial bear. The bilby has long ears, and is a symbol of Easter in Australia, where rabbits are held in ill repute. The wombat is a large burrowing animal. The echidna, also known as the spiny anteater, is a monotreme. The platypus is an improbable beast.

djb_wombat.xsl
Any questions?
Uh-oh. There should be a picture of a wombat here!