Multiple xml reposnses in one transform

anthonym · November 4th, 2011, 12:50 PM

I have been given a task to write an xml transformation for trades coming onto a system. However, sometimes there will be multiple trades in one xml document.

I have created a transform that will seperate them into multiple output xml trades but within the same document.. as xslt can only outrput into one document.
the content of the document is fine (i think ) but when i run the transform, within a c# exe, which is the final goal of the project, i get the following error

System.InvalidOperationException: Token StartElement in state EndRootElement would result in an invalid XML document

Basically the teransfom cannot handle multiple 'trades' withon one transform....

Is there any way round this to get all the output trades in one document as seperate xml nodes but returned from a single transfom

thanks for yuor help

Martin Honnen · November 4th, 2011, 01:00 PM

Show us the relevant code such as the XSLT processor class you use, the way you generate the transformation result with C# and of course the XML input and XSLT.
XSLT output can be an XML fragment (external parsed entity) so multiple top level elements are allowed. But I guess you somehow feed it to an XmlWriter with the wrong XmlWriterSettings. If the XSLT processor is XslCompiledTransform, then make sure if you transform to an XmlWriter you create explicitly that you use the OutputSettings property of the XslCompiledTransform instance.

anthonym · November 4th, 2011, 01:04 PM

public static void Transform(string sXmlPath, string sXslPath, string outputFile)
{

//load the Xml doc
XPathDocument myXPathDoc = new XPathDocument(sXmlPath);

XmlDocument xmlReader = new XmlDocument();
xmlReader.Load(sXmlPath);

string xml = xmlReader.InnerXml;

StringWriter sw = new StringWriter();
using (XmlReader xri = XmlReader.Create(new StringReader(xml)))
using (XmlWriter xwo = XmlWriter.Create(sw))
{

XslCompiledTransform xslt = new XslCompiledTransform();
xslt.Load(sXslPath);
xslt.Transform(xri, xwo);
}

string outputXML = sw.ToString();
.......
.......
}

The output xml from the transform i know is sound, as whwen i run it through viual studio XSLT debugger.. it outputs correct xml with multiple output trades.......

But when i run it through the above code I get an exception (the exception handler is on the lwevel of the calling function.

anthonym · November 4th, 2011, 01:05 PM

i uploaded a response but waiting for the moderator to ok it.. apparently..
thanks

anthonym · November 4th, 2011, 01:07 PM

public static void Transform(string sXmlPath, string sXslPath, string outputFile)
{

//load the Xml doc
XPathDocument myXPathDoc = new XPathDocument(sXmlPath);

XmlDocument xmlReader = new XmlDocument();
xmlReader.Load(sXmlPath);

string xml = xmlReader.InnerXml;

StringWriter sw = new StringWriter();
using (XmlReader xri = XmlReader.Create(new StringReader(xml)))
using (XmlWriter xwo = XmlWriter.Create(sw))
{

XslCompiledTransform xslt = new XslCompiledTransform();
xslt.Load(sXslPath);
xslt.Transform(xri, xwo);
}

string txt = sw.ToString();

Martin Honnen · November 4th, 2011, 01:17 PM

Use

Code:

XslCompiledTransform xslt = new XslCompiledTransform();
xslt.Load(sXslPath);
using (XmlWriter xwo= XmlWriter.Create(sw, xslt.OutputSettings)) {
  xslt.Transform(xri, xwo);
}

or don't create an XmlWriter at all, instead directly transform to your StringWriter

Code:

using (StringWriter sw = new StringWriter()) {
  xslt.Transform(xri, null, sw);
}

Martin Honnen · November 4th, 2011, 01:59 PM

Also the code you have is taking unnecessary steps, if you have a variable with the file path or URL of the XML input document then the Transform method has overloads which take that path or URL as its first argument, so there is no need to create an XPathDocument or XmlDocument and of course no need to then take the InnerXml to parse that again, you can simply use http://msdn.microsoft.com/en-us/library/ms163431.aspx with e.g.

Code:

public static void Transform(string sXmlPath, string sXslPath, string outputFile)
{
  XslCompiledTransform xslt = new XslCompiledTransform();
  xslt.Load(sXslPath);
  xslt.Transform(sXmlPath, outputFile);
}