DOMNode::appendChild

(PHP 5, PHP 7, PHP 8)

DOMNode::appendChild — Adds new child at the end of the children

说明

public DOMNode::appendChild ( DOMNode $node ) : DOMNode|false

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.

参数

node: The appended child.

返回值

The node added.

错误／异常

DOM_NO_MODIFICATION_ALLOWED_ERR: Raised 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.

范例

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();
?>

参见

DOMNode::insertBefore() - Adds a new child before a reference node
DOMNode::removeChild() - Removes child from list of children
DOMNode::replaceChild() - Replaces a child

User Contributed Notes

cweiske at php dot net 05-Nov-2017 01:56


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);

}

?>

frame at dynamiccreated dot de 01-Dec-2010 04:14


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.

krisdover at hotmail dot com 31-May-2008 08:49


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

jrtayloriv at gmail dot com 30-Mar-2008 04:56


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>