parameterized doctype in xsl:stylesheet

Question

How could I inject a --stringparam (xsltproc) into the DOCTYPE of a XSL stylesheet? The --stringparam is specified from the command line.

I have several books in docbook5 format I want to process with the same customization layer, each book having an unique identifier, here "demo", so I'm running something like

xsltproc --stringparam course.name demo ...

for each book.

Obviously the parameter is not recognized as such, but as verbatim text, giving the error:

warning: failed to load external entity "http://edu.yet-another-project.com/course/$(course.name)/entities.ent"

Here it is how I've tried, which won't work:

<?xml version='1.0'?>
<!DOCTYPE stylesheet [
<!ENTITY % myent SYSTEM "http://edu.yet-another-project.com/course/$(course.name)/entities.ent">
%myent;
]>
<xsl:stylesheet  
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
        version="1.0">

<!-- the docbook template used -->
<xsl:import href="http://docbook.org/ns/docbook/xhtml/chunk.xsl"/>

<!-- processor parameters -->
<xsl:param name="html.stylesheet">default.css</xsl:param>
<xsl:param name="use.id.as.filename">1</xsl:param>
<xsl:param name="chunker.output.encoding">UTF-8</xsl:param>
<xsl:param name="chunker.output.indent">yes</xsl:param>
<xsl:param name="navig.graphics">1</xsl:param>
<xsl:param name="generate.revhistory.link">1</xsl:param>
<xsl:param name="admon.graphics">1</xsl:param>

<!-- here more stuff -->
</xsl:stylesheet>

Ideas?

Answer 1

From http://www.w3.org/TR/xslt#output

<xsl:output
  method = "xml" | "html" | "text" | qname-but-not-ncname 
  version = nmtoken 
  encoding = string 
  omit-xml-declaration = "yes" | "no"
  standalone = "yes" | "no"
  doctype-public = string 
  doctype-system = string 
  cdata-section-elements = qnames 
  indent = "yes" | "no"
  media-type = string />

So, when using XSLT 1.0 you can't parameterize public nor system DOCTYPE strings.

From http://www.w3.org/TR/xslt20/#element-result-document

<xsl:result-document
  format? = { qname }
  href? = { uri-reference }
  validation? = "strict" | "lax" | "preserve" | "strip"
  type? = qname
  method? = { "xml" | "html" | "xhtml" | "text" |
  qname-but-not-ncname }
  byte-order-mark? = { "yes" | "no" }
  cdata-section-elements? = { qnames }
  doctype-public? = { string }
  doctype-system? = { string }
  encoding? = { string }
  escape-uri-attributes? = { "yes" | "no" }
  include-content-type? = { "yes" | "no" }
  indent? = { "yes" | "no" }
  media-type? = { string }
  normalization-form? = { "NFC" | "NFD" | "NFKC" | "NFKD" |
  "fully-normalized" | "none" | nmtoken }
  omit-xml-declaration? = { "yes" | "no" }
  standalone? = { "yes" | "no" | "omit" }
  undeclare-prefixes? = { "yes" | "no" }
  use-character-maps? = qnames
  output-version? = { nmtoken }>
  <!-- Content: sequence-constructor -->
</xsl:result-document>

In XSLT 2.0 you can use xsl:result-document instruction for that task.

Answer 2

The course.name parameter is given to the XSLT processor. But it is the XML parser that sees the entity declaration containing $(course.name), and the parser won't know what to do with that. The entity cannot be expanded.

You need to declare course.name as a parameter in the stylesheet and then reference it somewhere in a custom template.