Question

I have a large number of HTML files that I need to process with XSLT, using an XML file to choose which HTML files, and what we’re doing with them.

I tried:

1. Use HTML Tidy to convert HTML -> XHTML / XML
2. Use document(filename) in XSLT to read in particular XHTML/XML files
3. …use standard nodeset commands to access e.g. “html/body/*”

This doesn’t work, because:

1. It seems that XSLT (tried: libXSLT/xsltproc … and Saxon) cannot process XHTML documents as external files (it sees the xhtml DOCTYPE, and refuses to parse it as nodes).

Fine (I thought) … XHTML is just XML, I just need to put it through HTML Tidy and say:

“output-xml yes … output-html no … output-xhtml no”

…but HTML Tidy ignores you if you attempt that, and forces html instead :(. It seems to be hardcoded to only output XML files if the input was XML to begin with.

Any ideas for how to:

1. Force HTML Tidy to obey the command-line parameters, and set the doctype I asked for
2. Force XSLTproc to parse xhtml DOCTYPEs as xml
3. …some other cunning way that will work?

NB: this has to work on OS X – it’s part of a build process for iOS apps. That shouldn’t be a big problem, but e.g. any windows-only tools aren’t available. I’d like to achieve this with standard open-source cross-platform tools (like tidy, libxslt, etc)

Answer 1

I finally discovered why XSLTproc / Saxon were refusing to parse the files if they were passed-in with a DOCTYPE html:

The DOCTYPE of the external document alters how they interpret the
xmlns (namespace) directive. Tidy was declaring (correctly)
“xmlns=…the xhtml: namespace” – so all my node-names were … I don’t know: non-existent? … inside my XSLT. XSLT was just ignoring them, as if they didn’t exist – it needed me to provide a compatible mapping to the same namespace

…strangely, if the DOCTYPE was xml, then they happily ignored the xmlns command – or they allowed me to reference nodes by unqualified name. This fooled me into thinking that they were point-blank ignoring the nodesets inside the xhtml DOCTYPE’d version.

So, the “solution” is something like this:

1. modify your XSLT stylesheet to ALSO import the “xhtml” namespace – NB: this is required so that you can reference the nodes in the external files
2. write all your XSL match / select / template rules with the “xhtml” prefix on every node (and every attribute, I think?)
3. let Tidy output whatever it wants: it doesn’t matter, it’ll Just Work, once you have the namespace support in there

Example code:

1. Your stylesheet goes from this:

   <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
   

   …to this:

   <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:xhtml="http://www.w3.org/1999/xhtml">
   

2. Your select / match / document-import goes from this:

   <xsl:copy-of select="document('html-files/file1.htm')/html/body"/>
   

   …to this:

   <xsl:copy-of select="document('html-files/file1.htm')/xhtml:html/xhtml:body"/>
   

NB: just to be clear: if you ignore namespaces, then it seems XSLT will work on files that are unDOCTYPED, even if they have a namespace in them. Don’t make the mistake I made of thinking your XSLT is correct just because it appears to be 🙂