Add clone or copy constructor to XML Node

Can you elaborate on what you mean by "further processing"? Do you plan to append the node back into a node tree?

Yes I want to append it back to a node tree after changing one or two attributes. I have used this for example to dynamically create message driven beans in an ejb.xml,sun-ejb-jar.xml file.
I will use one of the existing nodes as template and change the name and the class and add it back to the config tree. So my newly created node has the same pool size, timeouts like the template node.

Attached a short example script which should show what I want to archive with the cloning:

import groovy.xml.XmlUtil

def xml = '''
<projects>
    <project>
        <id>First Project</id>
        <workers>
            <worker>Me</worker>
            <worker>Myself</worker>
            <worker>I</worker>
        </workers>
    </project>
    <project>
        <id>Second Project</id>
        <workers>
            <worker>Me</worker>
            <worker>Myself</worker>
            <worker>I</worker>
        </workers>
    </project>
</projects>
'''
def root = new XmlParser().parseText(xml)
def firstProjectNode = root.'project'[0]
def clonedProjectNode = new XmlParser().parseText(XmlUtil.serialize(firstProjectNode))
clonedProjectNode.'id'[0].value = 'Third Project'
root.append(clonedProjectNode)
println XmlUtil.serialize(root)

Conceptually, this appears to be a useful extension. Some implementation issues do arise however, so it might take a little bit of time to work out a final solution - but perhaps a partial step forward might become clear in the meantime.

Short-term questions: Do we implement a cloneNode() method (or just override clone() and implement Cloneable) or provide a copy constructor? Also, I suspect it needs to be a deep clone method. Is there ever a case where a shallow clone might also be desirable?

Longer-term questions: Should we also provide a similar facility for XmlSlurper? DOMCategory?

Since a suitable workaround exists its OK for me if the solution take some time. I agree that it should be a deep clone method, else it has strange effects when the child nodes are not copied. With Gpath its to easy to get a reference or change something on a child node, which would change the original XML node.

For developing I guess a cloneNode() method is the cleanest solution, since you will find it when you search for clone in your IDE and its behaves like the dom.Node api (http://docs.oracle.com/javase/6/docs/api/org/w3c/dom/Node.html).

Actually, NodeList supports clone (by virtue of extending ArrayList) but only with shallow copying. It seems worth fixing that regardless of any other changes.

I ended up just fixing this by augmenting clone for Node and NodeList. The same approach can't be used for XmlSlurper or DOMCategory, so let's close this issue off and we can consider other scenarios in separate issues if the need arises. Thanks for your suggestion.

Thanks for implementing. I am totally happy with an easy solution to clone a node (and now even a complete NodeList).