How to generate doctype declarations dynamically in XProc? - xproc

Question

Requirement:
Is to add correct Doctype declaration on the output xml [The root element of the input xml can be chapter or section element]. For Instance, consider the chapter element public identifier is PUBLIC "-//OASIS//DTD DocBook Chap XML V4.5//EN" and system identifier is "chap.dtd". Simillary for section element public identifier is PUBLIC "-//OASIS//DTD DocBook Sec XML V4.5//EN" and system identifier is "sec.dtd".
Input XML1: chapter.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook Chap XML V4.5//EN" "chap.dtd">
<chapter>
<title>Chapter Template Title</title>
<para>Text</para>
<section>
<title>Section Title</title>
<para>Section text</para>
</section>
</chapter>
Input XML2: section.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE section PUBLIC "-//OASIS//DTD DocBook Chap XML V4.5//EN" "chap.dtd">
<section>
<title>Section Title</title>
<para>Section text</para>
</section>
XSLT file: test.xsl:
Stylesheet just copies input xml to output and adds #sec on all section elements
Stylesheet adds correct doctype declaration to output xml, because
the input xml root element can be or element
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
<xsl:template name="add-doctype-declaration">
<xsl:choose>
<xsl:when test="/chapter">
<xsl:text disable-output-escaping="yes">
<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook Chap XML V4.5//EN" "chap.dtd">
</xsl:text>
</xsl:when>
<xsl:when test="/section">
<xsl:text disable-output-escaping="yes">
<!DOCTYPE section PUBLIC "-//OASIS//DTD DocBook Sec XML V4.5//EN" "sec.dtd">
</xsl:text>
</xsl:when>
</xsl:choose>
</xsl:template>
<xsl:template match="/">
<xsl:call-template name="add-doctype-declaration"/>
<xsl:apply-templates/>
</xsl:template>
<!-- Identity Template -->
<xsl:template match="#*|*|processing-instruction()">
<xsl:copy>
<xsl:apply-templates select="#*|node()"/>
</xsl:copy>
</xsl:template>
<xsl:template match="section">
<xsl:copy>
<xsl:apply-templates select="#*"/>
<xsl:attribute name="sec">
<xsl:number/>
</xsl:attribute>
<xsl:apply-templates/>
</xsl:copy>
</xsl:template>
</xsl:stylesheet>
Expected output.xml for Input XML1
<?xml version="1.0" encoding="utf-8"?> Input XML1:
<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook Chap XML V4.5//EN" "chap.dtd">
<chapter>
<title>Chapter Template Title</title>
<para>Text</para>
<section sec="1">
<title>Section Title</title>
<para>Section text</para>
</section>
</chapter>
Expected output.xml for Input XML2
<?xml version="1.0" encoding="utf-8"?> Input XML1:
<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook Sec XML V4.5//EN" "sec.dtd">
<section sec="1">
<title>Section Title</title>
<para>Section text</para>
</section>
Using any XSLT engine, the transformation works absolutely fine, and able to get the expected output
But, if the transformation is done through XProc I end up with the following error. Can someone help in resolving this error
err:XD0001 : XD0001 It is a dynamic error if a non-XML resource is produced on a step output or arrives on a step input.
XProc file: test.xpl
<?xml version="1.0" encoding="UTF-8"?>
<p:declare-step xmlns:p="http://www.w3.org/ns/xproc"
xmlns:c="http://www.w3.org/ns/xproc-step" version="1.0" name="testing">
<p:input port="source">
<p:document href="chapter.xml"/>
</p:input>
<p:output port="result">
<p:empty/>
</p:output>
<p:xslt version="1.0" name="transform">
<p:input port="stylesheet">
<p:document href="test.xsl"/>
</p:input>
<p:input port="parameters">
<p:empty/>
</p:input>
</p:xslt>
<!-- Assume that there is another transform happening for chapter/section xml -->
<p:xslt version="1.0" name="transform2">
<p:input port="stylesheet">
<p:document href="test2.xsl"/>
</p:input>
<p:input port="parameters">
<p:empty/>
</p:input>
</p:xslt>
<p:store omit-xml-declaration="false" encoding="utf-8" name="serialize">
<p:with-option name="href" select="output.xml"/>
</p:store>
</p:declare-step>

Answer 1

Again look at
Here is two simple examples that shows that you don't need to contextualize the Doctype generation
Section http://www.sharexml.com/x/get?k=uWn0KA7RThnt
Chapter http://www.sharexml.com/x/get?k=wAJlbUJfzIYQ
[UPDATED AFTER ANSWER]
And if you want that doctype change dynamically
Section http://www.sharexml.com/x/get?k=pBAwCds86RnQ
Chapter http://www.sharexml.com/x/get?k=JHEWghzgWIq1
Hope this helps