I have three xml files I'd like to merge.

base.xml
Qt Code: 
  1. <symbols>
  2.   <circle>
  3.     <n_points>0</n_points>
  4.   </circle>
  5. </symbols>
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rect.xml
Qt Code: 
  1. <rectangle>
  2.   <points>
  3.     <n_points>4</n_points>
  4.     <point>
  5.       <x>1.0</x>
  6.       <y>2.0</y>
  7.     </point>
  8.     <point>
  9.       <x>6.0</x>
  10.       <y>2.0</y>
  11.     </point>
  12.     <point>
  13.       <x>1.0</x>
  14.       <y>4.0</y>
  15.     </point>
  16.     <point>
  17.       <x>6.0</x>
  18.       <y>4.0</y>
  19.     </point>
  20.   </points>
  21. </rectangle>
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3d.xml
Qt Code: 
  1. <rectangle>
  2.   <points>
  3.     <point>
  4.       <z>7.0</z>
  5.     </point>
  6.     <point>
  7.       <z>8.0</z>
  8.     </point>
  9.     <point>
  10.       <z>9.0</z>
  11.     </point>
  12.     <point>
  13.       <z>10.0</z>
  14.     </point>
  15.   </points>
  16. </rectangle>
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I want the end result to be like this...
Qt Code: 
  1. <symbols>
  2.   <circle>
  3.     <n_points>0</n_points>
  4.   </circle>
  5.   <rectangle>
  6.     <points>
  7.       <n_points>4</n_points>
  8.       <point>
  9.         <x>1.0</x>
  10.         <y>2.0</y>
  11.         <z>7.0</z>
  12.       </point>
  13.       <point>
  14.         <x>6.0</x>
  15.         <y>2.0</y>
  16.         <z>8.0</z>
  17.       </point>
  18.       <point>
  19.         <x>1.0</x>
  20.         <y>4.0</y>
  21.         <z>9.0</z>
  22.       </point>
  23.       <point>
  24.         <x>6.0</x>
  25.         <y>4.0</y>
  26.         <z>10.0</z>
  27.       </point>
  28.     </points>
  29.   </rectangle>
  30. </symbols>
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I constructed the following method:
Qt Code: 
  1. void DomHelper::merge(QDomNode mergeInto, const QDomNode &mergeFrom) {
  2.   bool foundMatchingNode = false;
  3.   QDomNodeList children = mergeInto.childNodes();
  4.  
  5.   for (int i = 0; i < children.size(); ++i) {
  6.     if (children.at(i) == mergeFrom) {
  7.       foundMatchingNode = true;
  8.       break;
  9.     }
  10.   }
  11.  
  12.   if (foundMatchingNode) {
  13.     DomElementContainer elements(mergeInto, mergeFrom.toElement().tagName());
  14.     foreach(QDomElement element, elements) {
  15.       QDomNodeList elementChildren = mergeFrom.childNodes();
  16.       int count = elementChildren.size();
  17.       for (int i = 0; i < count; ++i) {
  18.         merge(element, elementChildren.at(i));
  19.       }
  20.     }
  21.   } else {
  22.     mergeInto.appendChild(mergeFrom);
  23.     m_doc = mergeInto.ownerDocument;
  24.   }
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DomElementContainer is just a class I made instead of using elementsByTagName() ... actually I borrowed it from someone else and modified it but still, it works.

m_doc is what I return to my QTreeView widget to view the result. The result is not what I want though and I've been staring at my code for too long so I can't figure out how to fix it either. I would greatly appreciate some help here.

One other issue is that the merge should be correctly done no matter the order although base.xml always exists before the others. So...

base << rect << 3d

shall produce the same output as....

base << 3d << rect