TouchXML Objective-C Create Document

Question

I'm trying to create a document with TouchXML. I followed up this tutorial https://github.com/TouchCode/TouchXML/blob/develop/Documentation/TouchXMLParsing.markdown to parse the XML, that's working fine. Now I try to generate the same XML for. I tried with

CXMLElement *piglet = [CXMLElement elementWithName:@"piglet" stringValue:@"1"];
CXMLElement *pigletList = [CXMLElement elementWithName:@"pigletlist"];
[pigletList addChild:piglet];
CXMLElement *name = [CXMLElement elementWithName:@"name" stringValue:@"Nifnif"];
[piglet addChild:name];
CXMLDocument *theDocument = [CXMLDocument documentWithRootElement:pigletList];
NSLog(@"document: %@", theDocument);

And the result is

<pigletlist>
  <piglet>1<name>Nifnif</name></piglet>
</pigletlist>

So my question: How can I create a piglet like

<piglet id="1">

I tried with

CXMLElement *piglet = [CXMLElement elementWithName:[NSString stringWithFormat:@"piglet id=\"1\""]];

That worked fine, but not for a root element at the top, in my specific case I have an ID in my first XML-Element too and with [NSString stringWithFormat] it's placed in the closing tag too.

Thanks a lot, matz