How to change root of a node with DomDocument methods?

Question

How to only change root\'s tag name of a DOM node?

In the DOM-Document model we can not change the property documentElement of a DOMElement

Answer 1

First, you need to understand that the DOMDocument is only the hierarchical root of the document-tree. It's name is always #document. You want to rename the root-element, which is the $document->documentElement.

If you want to copy nodes form a document to another document, you'll need to use the importNode() function: $document->importNode($nodeInAnotherDocument)

Edit:

renameNode() is not implemented yet, so you should make another root, and simply replace it with the old one. If you use DOMDocument->createElement() you don't need to use importNode() on it later.

$oldRoot = $doc->documentElement;
$newRoot = $doc->createElement('new-root');

foreach ($oldRoot->attributes as $attr) {
  $newRoot->setAttribute($attr->nodeName, $attr->nodeValue);
}

while ($oldRoot->firstChild) {
  $newRoot->appendChild($oldRoot->firstChild);
}

$doc->replaceChild($newRoot, $oldRoot);