Deserializing an xml element in WCF with XML Declaration

Question

I have a little WCF service that has the following signature:

string ProcessMessage(XmlElement xmlSource);

When I get a request without the xml declaration, the webservice works fine, but as soon as the xml declaration is added, I get a crash.

The request that works

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:tem="http://tempuri.org/">
    <soapenv:Header/>
    <soapenv:Body>
        <tem:ProcessMessage>
            <tem:xmlSource>            
                <clipped>elements here</clipped>
            </tem:xmlSource>
        </tem:ProcessMessage>
    </soapenv:Body>
</soapenv:Envelope>

The request that doesn't work

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:tem="http://tempuri.org/">
    <soapenv:Header/>
    <soapenv:Body>
        <tem:ProcessMessage>
            <tem:xmlSource>
            <?xml version="1.0" encoding="UTF-8"?>                
                <clipped>elements here</clipped>
            </tem:xmlSource>
        </tem:ProcessMessage>
    </soapenv:Body>
</soapenv:Envelope>

And the crash:

<Message>No characters can appear before the XML declaration. Line 7, position 14.</Message>
                     <StackTrace>at System.Xml.XmlExceptionHelper.ThrowXmlException(XmlDictionaryReader reader, String res, String arg1, String arg2, String arg3)
   at System.Xml.XmlUTF8TextReader.ReadDeclaration()
   at System.Xml.XmlUTF8TextReader.Read()
   at System.Xml.XmlBaseReader.MoveToContent()
   at System.Xml.Serialization.XmlSerializationReader.ReadXmlNode(Boolean wrapped)
   at Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderINBUWProcessingService.Read1_ProcessMessage()
   at Microsoft.Xml.Serialization.GeneratedAssembly.ArrayOfObjectSerializer.Deserialize(XmlSerializationReader reader)
   at System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader xmlReader, String encodingStyle, XmlDeserializationEvents events)</StackTrace>
                     <Type>System.Xml.XmlException</Type>
                  </InnerException>
                  <Message>There is an error in XML document (7, 14).</Message>
                  <StackTrace>at System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader xmlReader, String encodingStyle, XmlDeserializationEvents events)
   at System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader xmlReader, String encodingStyle)
   at System.ServiceModel.Dispatcher.XmlSerializerOperationFormatter.DeserializeBody(XmlDictionaryReader reader, MessageVersion version, XmlSerializer serializer, MessagePartDescription returnPart, MessagePartDescriptionCollection bodyParts, Object[] parameters, Boolean isRequest)</StackTrace>
                  <Type>System.InvalidOperationException</Type>

What I assume is happening is that the WCF service is reading the whole soap envelop as one xml document, then when it encounters the xml declaration (for the parameter xmlSource) and interprets it as the xml document for the whole soap envelope. This is where it crashes and says that the xml declaration must be the first part of the document.

Is there a way to fix this or strip out xml declarations from the request before it hits the webservice?

What are you using as the client for the WCF service? Are you building your own requests from scratch or using a Web Reference or a WCF ChannelFactory> — Polly Shaw
– Polly Shaw, Commented Aug 19, 2013 at 22:06
The requests are coming in from a JAVA app that I unfortunately have no control over. — Matt R
– Matt R, Commented Aug 20, 2013 at 14:21
If you really can't get the client to send valid XML then I think you might have to create a non-WCF handler which accepts the content, cleans it and then forwards it to the WCF service. I had a look at the various interception points as described in this document but they all seem to be after the request has been parsed as SOAP, which will fail if it isn't valid XML. — Polly Shaw
– Polly Shaw, Commented Aug 20, 2013 at 22:19

carlosfigueira · Accepted Answer · 2013-08-19 22:54:17Z

1

The XML which you're sending to the service is invalid. According to the XML Spec, the XML Declaration can only appear in the prolog of the document. A well-formed XML document is composed of prolog + a root element. And XML declarations are not allowed in the element node.

You may want to consider passing the document with the XML declaration as a string (e.g., inside a <!\[CDATA\[ section, or escaping the XML characters), so you'll be able to receive a XML "document" within the XML request.

answered Aug 19, 2013 at 22:54

carlosfigueira

87.7k14 gold badges137 silver badges176 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Deserializing an xml element in WCF with XML Declaration

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related