MATLAB: How to append a node to an ‘.xml’ structure within a function

Question

I am trying to send an xml structure to a function, append a new node, and return the modified structure. This is because the child structure being appended will be very common to many '.xml' files and I don't want to re-write the same code every time.

If I am not in a function the following works:

           docNode = com.mathworks.xml.XMLUtils.createDocument('ugcs-Transfer');
           parent_node = docNode.createElement('parent')
           docNode.appendChild(parent_node)
           child_node = docNode.createElement('child');
           parent_node.appendChild(child_node);

If I try to pass it to a function like this:

   docNode = com.mathworks.xml.XMLUtils.createDocument('ugcs-Transfer');
   parent_node = docNode.createElement('parent')
   docNode.appendChild(parent_node)
   docNode = myFunction(docNode)

This function will not append the child to the parent node:

Z = my_function(docNode)
           child_node = docNode.createElement('child');
           parent_node.appendChild(child_node);  % This line produces an error: Undefined variable "parent_node" or ...
%                                                  class "parent_node.appendChild".
           Z = docNode
end

The desired end state would be:

%<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
%        <parent>
%            <child>

Any help would be appreciated,

Paul

Answer 1

I got the answer for this from a colleague.

The line of code I needed was:

parent_node=docNode1.getElementsByTagName('Parent').item(0)