(PHP 5)
DOMDocument::createElement — Create new element node
This function creates a new instance of class DOMElement. Dieser Knoten wird in Ihrem Dokument nicht sichtbar sein, bis dieser zum Beispiel mit der Funktion DOMNode->appendChild() eingefügt wird.
The tag name of the element.
The value of the element. By default, an empty element will be created. The value can also be set later with DOMElement->nodeValue.
Returns a new instance of class DOMElement or FALSE if an error occured.
Raised if name contains an invalid character.
Beispiel #1 Creating a new element and inserting it as root
<?php
$dom = new DOMDocument('1.0', 'utf-8');
$element = $dom->createElement('test', 'This is the root element!');
// We insert the new element as root (child of the document)
$dom->appendChild($element);
echo $dom->saveXML();
?>
Das oben gezeigte Beispiel erzeugt folgende Ausgabe:
<?xml version="1.0" encoding="utf-8"?> <test>This is the root element!</test>
Hinweis:
The value will not be escaped. Use DOMDocument::createTextNode() to create a text node with escaping support.
You may think insertBefore and insertAfter is a direct alternative for appendChild, this is not the case.
<?php
$dom = new DOMDocument();
$dom->load($file);
$dom->appendChild($newNode); //Works fine
$dom->insertBefore($newNode, $refNode); //Will fail
$refNode->parentNode->insertBefore($newNode, $refNode); // thanx to yasindagli (first post)
?>
To create elements with attributes,
<?php
function createElement($domObj, $tag_name, $value = NULL, $attributes = NULL)
{
$element = ($value != NULL ) ? $domObj->createElement($tag_name, $value) : $domObj->createElement($tag_name);
if( $attributes != NULL )
{
foreach ($attributes as $attr=>$val)
{
$element->setAttribute($attr, $val);
}
}
return $element;
}
$dom = new DOMDocument('1.0', 'utf-8');
$elm = createElement($dom, 'foo', 'bar', array('attr_name'=>'attr_value'));
$dom->appendChild($elm);
echo $dom->saveXML();
?>
outputs :
<?xml version="1.0" encoding="utf-8"?>
<foo attr_name="attr_value">bar</foo>
Note that the NUL character "\0" is not in the list of invalid characters for $name, so no error is triggered, but the tag name will be truncated at the null byte:
<?php
$dom = new DOMDocument('1.0', 'utf-8');
$el = $dom->createElement('foo' . "\0" . 'bar', 'Hello World');
echo $el->tagName; // outputs "foo"
?>
In response to 'mikek dot nospam at nospam dot muonics dot com', here is a more correct version, as values have to be UTF-8 encoded, and there's absolutely no reason to create an extra DOMElement class.
<?php
class ADOMDocument extends DOMDocument {
function __construct($version = null, $encoding = null) {
parent::__construct($version, $encoding);
}
public function createElement($tagName, $value=null) {
$node=parent::createElement($tagName);
if (!is_null($value)) {
$node->appendChild(
$this->createTextNode(utf8_encode($value))
);
}
return $node;
}
public function createElementNS($namespaceURI, $qualifiedName, $value=null) {
$node=parent::createElementNS($namespaceURI, $qualifiedName);
if (!is_null($value)) {
$node->appendChild(
$this->createTextNode(utf8_encode($value))
);
}
return $node;
}
}
?>
Note that the second parameter (value), although convenient, is non-standard. You should create elements like this instead:
<?php
$doc = new DOMDocument('1.0', 'iso-8859-1');
$root = $doc->createElement('test');
$doc->appendChild($root);
$root_text = $doc->createTextNode('This is the root element!');
$root->appendChild($root_text);
print $doc->saveXML();
?>
Or, alternatively, extend the DOMDocument class and add your own custom, convenience method to avoid intruding on the standard:
<?php
class CustomDOMDocument extends DOMDocument {
function createElementWithText($name, $child_text) {
// Creates an element with a child text node
// @param string $name element tag name
// @param string $child_text child node text
// @return object new element
$element = $this->createElement($name);
$element_text = $this->createTextNode($child_text);
$element->appendChild($element_text);
return $element;
}
}
$doc = new CustomDOMDocument('1.0', 'iso-8859-1');
$root = $doc->createElementWithText('test', 'This is the root element!');
$doc->appendChild($root);
print $doc->saveXML();
?>
Also use caution with (or avoid) the 'DOMElement->nodeValue' property. It can return some unexpected values and changing its value will replace (remove) all descendants of the element with a single text node. It's also non-standard; according to the DOM spec it should return NULL.
With regard to the note below about needing htmlentities to avoid warnings about unterminated entity references, I thought it worthwhile to mention that that you don't need to with createTextNode and DOMText::__construct. If you mix both methods of setting text nodes and do (or don't) apply htmlentities consistently to all data to be displayed, you'll get &s (or warnings and badly-formed xml).
It's probably in one's best interest to extend DOMElement and DOMDocument so that it creates a DOMText node and appends it, rather than passing it up to the DOMElement constructor. Otherwise, good luck using (or not using) htmlentities in all the right places in your code, especially as code changes get made.
<?php
class XDOMElement extends DOMElement {
function __construct($name, $value = null, $namespaceURI = null) {
parent::__construct($name, null, $namespaceURI);
}
}
class XDOMDocument extends DOMDocument {
function __construct($version = null, $encoding = null) {
parent::__construct($version, $encoding);
$this->registerNodeClass('DOMElement', 'XDOMElement');
}
function createElement($name, $value = null, $namespaceURI = null) {
$element = new XDOMElement($name, $value, $namespaceURI);
$element = $this->importNode($element);
if (!empty($value)) {
$element->appendChild(new DOMText($value));
}
return $element;
}
}
$doc1 = new XDOMDocument();
$doc1_e1 = $doc1->createElement('foo', 'bar & baz');
$doc1->appendChild($doc1_e1);
echo $doc1->saveXML();
$doc2 = new XDOMDocument();
$doc2_e1 = $doc2->createElement('foo');
$doc2->appendChild($doc2_e1);
$doc2_e1->appendChild($doc2->createTextNode('bar & baz'));
echo $doc2->saveXML();
?>
Text specified in createElement:
<?xml version=""?>
<foo>bar & baz</foo>
Text added via createTextNode:
<?xml version=""?>
<foo>bar & baz</foo>
To avoid warning message "unterminated entity reference" you may use htmlentities() for escaping supplied value:
<?php
//...
$dom->createElement('name', htmlentities($text))
//...
?>