XslTransform throws exception when output is an XML fragment

[John Meyer]

I have an application where I create an xml fragment using
an XslTransform object. However, if I use the following
output method,

<xsl:output method="xml" version="1.0" encoding="UTF-8"
indent="no" omit-xml-declaration="yes" standalone="no" />

some of my transforms fail with the following exception:

System.Xml.Xsl.XsltException: There are multiple root
elements in the output XML.

This seems like non-conformant behavior because the XSLT
spec [0] specifies that an XML Process must output the
result tree as a "well-formed XML external general parsed
entity." A well-formed external general parsed entity
(EGPE) may contain multiple top-level elements and is not
subject to the single root-element restriction. The formal
definition of an EPGE is found in the XML Specification
[1].

Is there a workaround for this behavior as this means that
a transform cannot output an XML fragment. Creating a root
element involves adding unnessary complexity and
performance costs to my application.

John Meyer
Senior Software Engineer
Clinician Support Technology
1 Wells Avenue, Suite 201
Newton, MA 02459
www.cstlink.com
[0]
http://www.w3.org/TR/xslt#section-XML-Output-Method

[1]
http://www.w3.org/TR/REC-xml#NT-extParsedEnt

[Oleg Tkachenko]

John Meyer wrote:

I have an application where I create an xml fragment using
an XslTransform object. However, if I use the following
output method,

<xsl:output method="xml" version="1.0" encoding="UTF-8"
indent="no" omit-xml-declaration="yes" standalone="no" />

some of my transforms fail with the following exception:

System.Xml.Xsl.XsltException: There are multiple root
elements in the output XML.

How do you run the transformation? Chances are you are transforming to
XmlWriter, which supports writing of well-formed XML documents only.
Transformation to a Stream works just fine for me.
--
Oleg Tkachenko
http://www.tkachenko.com/blog
Multiconn Technologies, Israel

[Anthony Christianson]

John,
I was unable to duplicate this problem.
Here is the code I tried.

System.IO.StringWriter writer = new System.IO.StringWriter();
System.Xml.Xsl.XslTransform xfrm = new System.Xml.Xsl.XslTransform();
XmlDocument xml = new XmlDocument();
xml.LoadXml( "<?xml version=\"1.0\" encoding=\"utf-8\" ?>
<WorkOrder><ProductID/><OrderDate/><ProductGroup><SerialNo/><SerialNo/><Seri
alNo/></ProductGroup></WorkOrder>");
XmlDocument xsl = new XmlDocument();
xsl.LoadXml( @"<?xml version=""1.0"" encoding=""utf-8"" ?><xsl:stylesheet
xmlns:xsl=""http://www.w3.org/1999/XSL/Transform""
version=""1.0""><xsl:output method=""xml"" version=""1.0""
encoding=""UTF-8"" indent=""no"" omit-xml-declaration=""yes""
standalone=""no"" /> <xsl:template match=""/""> <xsl:copy-of
select=""//SerialNo"" /> </xsl:template></xsl:stylesheet>" );
xfrm.Load( xsl.CreateNavigator());
xfrm.Transform(xml.CreateNavigator(),null,writer);
XmlDocumentFragment frag = xml.CreateDocumentFragment();
frag.InnerXml = writer.ToString();

"John Meyer" <jm****@cstlink.com> wrote in message
news:03****************************@phx.gbl...

I have an application where I create an xml fragment using
an XslTransform object. However, if I use the following
output method,

<xsl:output method="xml" version="1.0" encoding="UTF-8"
indent="no" omit-xml-declaration="yes" standalone="no" />

some of my transforms fail with the following exception:

System.Xml.Xsl.XsltException: There are multiple root
elements in the output XML.

This seems like non-conformant behavior because the XSLT
spec [0] specifies that an XML Process must output the
result tree as a "well-formed XML external general parsed
entity." A well-formed external general parsed entity
(EGPE) may contain multiple top-level elements and is not
subject to the single root-element restriction. The formal
definition of an EPGE is found in the XML Specification
[1].

Is there a workaround for this behavior as this means that
a transform cannot output an XML fragment. Creating a root
element involves adding unnessary complexity and
performance costs to my application.

John Meyer
Senior Software Engineer
Clinician Support Technology
1 Wells Avenue, Suite 201
Newton, MA 02459
www.cstlink.com
[0]
http://www.w3.org/TR/xslt#section-XML-Output-Method

[1]
http://www.w3.org/TR/REC-xml#NT-extParsedEnt