(PHP 5, PHP 7)
DOMDocument::createElement — Create new element node
This function creates a new instance of class DOMElement. 此节点出现在文档中，除非是用诸如 DOMNode->appendChild() 等函数来将其插入。
nameThe tag name of the element.
valueThe value of the element. By default, an empty element will be created. The value can also be set later with DOMElement::$nodeValue.
The value is used verbatim except that the < and > entity references will escaped. Note that & has to be manually escaped; otherwise it is regarded as starting an entity reference. Also " won't be escaped.
Returns a new instance of class DOMElement or FALSE
if an error occurred.
DOM_INVALID_CHARACTER_ERR
Raised if name contains an invalid character.
Example #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();
?>
以上例程会输出：
<?xml version="1.0" encoding="utf-8"?> <test>This is the root element!</test>
Example #2 Passing text containing an unescaped & as value
<?php
$dom = new DOMDocument('1.0', 'utf-8');
$element = $dom->createElement('foo', 'me & you');
$dom->appendChild($element);
echo $dom->saveXML();
?>
以上例程的输出类似于：
Warning: DOMDocument::createElement(): unterminated entity reference you in /in/BjTCg on line 4 <?xml version="1.0" encoding="utf-8"?> <foo/>
Note:
The
valuewill not be escaped. Use DOMDocument::createTextNode() to create a text node with escaping support.
To create an element with DomDocument and to escape ampersand in the value.
Do this:
$element = new DOMDocument('1.0', 'UTF-8');
$test = $element->createElement('text');
$test ->appendChild($element->createElement('name'))
->appendChild($element->createtextNode('& I am ampersand');
Remember:
If you want to perform multiple actions with a new node, you may need to create a copy of it before
means:
## Create an address to an unique memory block !
$td = $dom->createElement('td');
## Change some things in this original unique pattern
$td->setAttribute('class', 'saldo');
## clone the unique pattern to two own one's
$td1 = clone $td;
$td2 = clone $td;
## alter properties in each one
$td1->nodeValue = 'Ich bin die erste neue Node';
$td2->nodeValue = 'Ich bin die zweite neue Node';
## find the parent element
$tr = $dom->getElementById('t001-tr001');
## find the first and the last child (here only for clearity)
$first = $tr->firstChild;
$last = $tr->lastChild;
## produce the new nodes
$newtd1 = $tr->insertBefore($td1, $first);
$newtd2 = $tr->appendChild($td2);
conclusion:
YOU NEED AN ORIGINAL NEW NODE FOR EACH ACTION!
Although the built-in DOM functions are great, since they're designed to support generic XML, generating HTML DOMs becomes particularly verbose. I ended up writing this function to drastically speed things up.
Instead of calling something like
<?php
$div = $dom->createElement("div");
$div->setAttribute("class","MyClass");
$div->setAttribute("id","MyID");
$someOtherDiv->appendChild($div);
?>
you can accomplish the same thing with:
<?php
$div = newElement("div", $someOtherDiv, "class=MyClass;id=MyID");
?>
The "key1=value;key2=value" syntax is really fast to use, but obviously doesn't hold up if your content has those characters in it. So, you can also pass it an array:
<?php
$div = newElement("div", $someOtherDiv, array("class","MyClass"));
?>
Or an array of arrays, representing different attributes:
<?php
$div = newElement("form", $someOtherDiv, array(array("method","get"), array("action","/refer/?id=5");
?>
Here's the function:
<?php
function newElement($type, $insertInto = NULL, $params=NULL, $content="")
{
$tempEl = $this->dom->createElement($type, $content);
if(gettype($params) == "string" && strlen($params) > 0)
{
$attributesCollection =split(";", $params);
foreach($attributesCollection as $attribute)
{
$keyvalue = split("=", $attribute);
$tempEl->setAttribute($keyvalue[0], $keyvalue[1]);
}
}
if(gettype($params) == "array")
{
if(gettype($params[0]) == "array")
{
foreach($params as $attribute)
{
$tempEl->setAttribute($attribute[0], $attribute[1]);
}
} else {
$tempEl->setAttribute($params[0], $params[1]);
}
}
?>
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"
?>
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))
//...
?>