Append DOMDocument root element to another DOMDocument - php

Question

I have 2 "DOMDocument" objects - $original and $additional. What I want is to take all children from $additional DOMDocument and append it to the end of $original document.
My plan was to take root element of the $additional document. I tried to use:
$root = $additional->documentElement;
$original->appendChild($root)
But I receive error that appendChild expect DOMNode object as an argument.
I tried to access each children of the document through:
$additional->childNodes->item(0);
But it returns object of DOMElement. Can you advice how to get object of DOMNode class? What is the most convenient way to provide this import operation?
$original XML looks like:
<?xml version="1.0" encoding="utf-8"?>
<Product>
<RecordReference>345345</RecordReference>
<NotificationType>03</NotificationType>
<NumberOfPages>100</NumberOfPages
</Product>
$additional XML looks like:
<?xml version="1.0" encoding="utf-8"?>
<MainSubject>
<SubjectScheme>10</SubjectScheme>
</MainSubject>
What I want to have:
<?xml version="1.0" encoding="utf-8"?>
<Product>
<RecordReference>345345</RecordReference>
<NotificationType>03</NotificationType>
<NumberOfPages>100</NumberOfPages>
<MainSubject>
<SubjectScheme>10</SubjectScheme>
</MainSubject>
</Product>

Answer 1

A DOMElement is a DOMNode, DOMNode is the superclass. Here are several child classes for element, text and other nodes. Just iterate, import and append them.
$targetDom = new DOMDocument();
$targetDom->loadXML('<root/>');
$sourceDom = new DOMDocument();
$sourceDom->loadXml('<items><child/>TEXT</items>');
foreach ($sourceDom->documentElement->childNodes as $child) {
$targetDom->documentElement->appendChild(
$targetDom->importNode($child, TRUE)
);
}
This works with the document element, too.
$targetDom = new DOMDocument();
$targetDom->loadXML('<root/>');
$sourceDom = new DOMDocument();
$sourceDom->loadXml('<items><child/>TEXT</items>');
$targetDom->documentElement->appendChild(
$targetDom->importNode($sourceDom->documentElement, TRUE)
);
echo $targetDom->saveXml();
DOMDocument::importNode() creates a copy of the provided node in the context of the document. Only nodes belonging to a document can be appended to it.