XML Hacks

Process HTML with XSLT Using TagSoup

Use TSaxon, a variant of Saxon, and TagSoup to help transform HTML.

Stylesheets written in XSLT are the standard method of taking XML documents in one format and transforming them into HTML, XML documents in a different format, XHTML, or plain-text documents.

There are many XSLT processors. Michael Kay’s Saxon Version 6.5.3 (http://saxon.sourceforge.net/#F6.5.3) is a particularly mature and successful implementation for XSLT 1.0 and XPath 1.0. It is packaged as a Java JAR file called saxon.jar. You can download this JAR with the 6.5.3 distribution from the Saxon site on Sourceforge.

Now suppose, for example, that we want to extract just the header elements (h1, h2, h3, etc.) from an XHTML document and display them as progressively indented plain text (i.e., each h1 element is unindented, each h2 element is indented by a single space, h2 by two spaces, etc.).

The XSLT stylesheet outline.xsl does exactly what we want. It specifies an output method of text, and matches the h1 through h6 elements in the XHTML input, taking the content of each one and prepending the correct number of spaces. The textual content of other elements is suppressed.

The following command, executed in your working directory, will process outline.xsl and the XHTML document outline.xhtml using Saxon and will display the resulting indented plain text:

java -jar saxon.jar outline.xhtml outline.xsl

It so happens that outline.html contains only h1, h2, and h3 elements (borrowed ...