Weird behaviour when applying XLST in PL/SQL

Question

I came across this strange behaviour when applying XSLT to an XML document. Below is a simplified version, based on some code that I found in OTN
declare
indoc VARCHAR2(2000);
xsldoc VARCHAR2(2000);
myParser dbms_xmlparser.Parser;
indomdoc dbms_xmldom.domdocument;
xsltdomdoc dbms_xmldom.domdocument;
xsl dbms_xslprocessor.stylesheet;
outdomdocf dbms_xmldom.domdocumentfragment;
outnode dbms_xmldom.domnode;
proc dbms_xslprocessor.processor;
buf varchar2(2000);
begin
indoc := '<emp><empno> 1</empno> <fname> robert </fname> <lname>
smith</lname> <sal>1000</sal> <job> engineer </job> </emp>';
xsldoc :=
'<?xml version="1.0"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output encoding="utf-8"/>
<xsl:variable name="CR">
<xsl:text>
</xsl:text>
</xsl:variable>
<xsl:template match="/">
<xsl:value-of select="$CR" />
<xsl:value-of select="$CR" />
</xsl:template>
</xsl:stylesheet>';
myParser := dbms_xmlparser.newParser;
dbms_xmlparser.parseBuffer(myParser, indoc);
indomdoc := dbms_xmlparser.getDocument(myParser);
dbms_xmlparser.parseBuffer(myParser, xsldoc);
xsltdomdoc := dbms_xmlparser.getDocument(myParser);
xsl := dbms_xslprocessor.newstylesheet(xsltdomdoc, '');
proc := dbms_xslprocessor.newProcessor;
--apply stylesheet to DOM document  
outdomdocf := dbms_xslprocessor.processxsl(proc, xsl, indomdoc);
outnode := dbms_xmldom.makenode(outdomdocf);
-- PL/SQL DOM API for XMLType can be used here
dbms_xmldom.writetobuffer(outnode, buf);
dbms_output.put_line(buf);
end;
I would expect this to output two carriage returns and this is what I get with xsltproc on the Linux server. Instead, it outputs the entire source XML document without the tags, as shown below.
1 robert
smith1000 engineer 1 robert
smith1000 engineer
Now, if you change the definition of the CR variable to add some text, for example to
<xsl:variable name="CR">
<xsl:text>XX
</xsl:text>
It outputs:
XX
XX
which is what I would expect.
Does anyone have any idea what is going on here? Changing the variable definition to <xsl:variable name="CR" select="'&#xD;&#xA;'" /> fixes the problem by the way.

Answer 1

I came across this strange behaviour when applying XSLT to an XML document. Below is a simplified version, based on some code that I found in OTN
declare
indoc VARCHAR2(2000);
xsldoc VARCHAR2(2000);
myParser dbms_xmlparser.Parser;
indomdoc dbms_xmldom.domdocument;
xsltdomdoc dbms_xmldom.domdocument;
xsl dbms_xslprocessor.stylesheet;
outdomdocf dbms_xmldom.domdocumentfragment;
outnode dbms_xmldom.domnode;
proc dbms_xslprocessor.processor;
buf varchar2(2000);
begin
indoc := '<emp><empno> 1</empno> <fname> robert </fname> <lname>
smith</lname> <sal>1000</sal> <job> engineer </job> </emp>';
xsldoc :=
'<?xml version="1.0"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output encoding="utf-8"/>
<xsl:variable name="CR">
<xsl:text>
</xsl:text>
</xsl:variable>
<xsl:template match="/">
<xsl:value-of select="$CR" />
<xsl:value-of select="$CR" />
</xsl:template>
</xsl:stylesheet>';
myParser := dbms_xmlparser.newParser;
dbms_xmlparser.parseBuffer(myParser, indoc);
indomdoc := dbms_xmlparser.getDocument(myParser);
dbms_xmlparser.parseBuffer(myParser, xsldoc);
xsltdomdoc := dbms_xmlparser.getDocument(myParser);
xsl := dbms_xslprocessor.newstylesheet(xsltdomdoc, '');
proc := dbms_xslprocessor.newProcessor;
--apply stylesheet to DOM document  
outdomdocf := dbms_xslprocessor.processxsl(proc, xsl, indomdoc);
outnode := dbms_xmldom.makenode(outdomdocf);
-- PL/SQL DOM API for XMLType can be used here
dbms_xmldom.writetobuffer(outnode, buf);
dbms_output.put_line(buf);
end;
I would expect this to output two carriage returns and this is what I get with xsltproc on the Linux server. Instead, it outputs the entire source XML document without the tags, as shown below.
1 robert
smith1000 engineer 1 robert
smith1000 engineer
Now, if you change the definition of the CR variable to add some text, for example to
<xsl:variable name="CR">
<xsl:text>XX
</xsl:text>
It outputs:
XX
XX
which is what I would expect.
Does anyone have any idea what is going on here? Changing the variable definition to <xsl:variable name="CR" select="'&#xD;&#xA;'" /> fixes the problem by the way.