DOMElement cloning and appending: 'Wrong Document Error'

Question

There\'s something I don\'t fully understand about node cloning with the PHP\'s DOM api. Here\'s a sample file that quickly duplicates the issue I\'m coming across.

Answer 1

Use DOMDocument->importNode to import the node into the other document before adding it to the DOM.

Answer 2

You'll have to append the result of the importNode method to the DOM. Keep in mind that the method could return false when it cannot be imported

if ($importedNode = $doc2->importNode($root->cloneNode())) {
    $root2->appendChild($importedNode);
}

If you need to import the node, all of it's child nodes (resursively) and/or the node's attributes use the optional second parameter deep:

if ($importedNode = $doc2->importNode($root->cloneNode(), true)) {
    $root2->appendChild($importedNode);
}