(PHP 5, PHP 7, PHP 8)
DOMNode::appendChild — Adds new child at the end of the children
This function appends a child to an existing list of children or creates a new list of children. The child can be created with e.g. DOMDocument::createElement(), DOMDocument::createTextNode() etc. or simply by using any other node.
When using an existing node it will be moved.
nodeThe appended child.
The node added.
DOM_NO_MODIFICATION_ALLOWED_ERRRaised if this node is readonly or if the previous parent of the node being inserted is readonly.
DOM_HIERARCHY_REQUEST_ERR
Raised if this node is of a type that does not allow children of the
type of the node node, or if the node to
append is one of this node's ancestors or this node itself.
DOM_WRONG_DOCUMENT_ERR
Raised if node was created from a different
document than the one that created this node.
The following example will add a new element node to a fresh document.
Example #1 Adding a child
<?php
$doc = new DOMDocument;
$node = $doc->createElement("para");
$newnode = $doc->appendChild($node);
echo $doc->saveXML();
?>
Example #2 Nested children
<?php
$doc = new DOMDocument;
$headNode = $doc->createElement("head");
$doc->appendChild($headNode);
$titleNode = $doc->createElement("title");
$headNode->appendChild($titleNode);
echo $doc->saveXML();
?>
If you want to move the children of one node to another, you cannot simply iterate on $element->childNodes - you have to make an array first:
<?php
$children = [];
foreach ($elemWithChildren->childNodes as $child) {
$children[] = $child;
}
foreach ($children as $child) {
$targetElement->appendChild($child);
}
?>
Aware dealing with DOMNodeList and appendChild() on the same Node.
If you want to replace only the children not the DOMElement itself you probably foreach childNodes-property or get the DOMElements with a for-loop and item()-method of the DOMNodeList.
You will fail if you not clone the received single DOMElement. Actually the count of the DOMNodelist will be decreased on appendChild count but appendChild seems to refer to the old Nodelist and nothing visible will happen. Cloning will help.
What's not mentioned here is that DOMNode::appendChild() can also be used to move an existing node to another part of the DOMDocument, e.g.
<?php
$doc = new DOMDocument();
$doc->loadXML("<foobar><bar/><foo/></foobar>");
$bar = $doc->documentElement->firstChild;
$foo = $doc->documentElement->lastChild;
$foo->appendChild($bar);
print $doc->saveXML();
?>
This produces:
<?xml version="1.0"?>
<foobar><foo><bar/></foo></foobar>
Note that the nodes "<foo/>" and "<bar/>" were siblings, i.e. the first and last child of "<foobar>" but using appendChild() we were able to move "<bar/>" so that it is a child of "<foo/>".
This saves you the trouble of doing a DOMNode::removeChild($bar) to remove "<bar/>" before appending it as a child of "<foo/>".
Kris Dover
If you want to create nested DOM elements:
<?php
$doc = new DOMDocument();
$foo = $doc->createElement("foo");
$doc->appendChild($foo);
$bar = $doc->createElement("bar");
$foo->appendChild($bar);
$bazz = $doc->createElement("bazz");
$foo->appendChild($bazz);
echo $doc->saveXML();
?>
Is equivalent to:
<foo>
<bar></bar>
<bazz></bazz>
</foo>