DOMDocument
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DOMDocument::createElement

(PHP 5)

DOMDocument::createElement — Create new element node

说明

DOMElement DOMDocument::createElement ( string $name [, string $value ] )

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。

参数

name

The tag name of the element.

value

The value of the element. By default, an empty element will be created. The value can also be set later with DOMElement::$nodeValue.

返回值

Returns a new instance of class DOMElement or FALSE if an error occured.

错误/异常

DOM_INVALID_CHARACTER_ERR

Raised if name contains an invalid character.

范例

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>

注释

Note:

The value will not be escaped. Use DOMDocument::createTextNode() to create a text node with escaping support.

参见

DOMDocument
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PHP手册
PHP手册 - N: Create new element node

用户评论:

funkathustra (04-Mar-2012 04:44)

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]);
            }
        }
?>

lars dot c dot magnusson at gmail dot com (26-Nov-2010 09:56)

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)
?>

yasindagli at gmail dot com (17-Jun-2009 10:01)

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>

chris AT cmbuckley DOT co DOT uk (26-May-2009 03:45)

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"

?>

poison (05-Jul-2007 06:11)

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;
    }
}
?>

estill at gvtc dot com (12-Jun-2007 10:38)

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.

mikek dot nospam at nospam dot muonics dot com (04-Mar-2007 01:24)

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 &amp;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 &amp; baz</foo>

Text added via createTextNode:
<?xml version=""?>
<foo>bar &amp; baz</foo>

sergsokolenko at gmail dot com (30-Jan-2007 12:11)

To avoid warning message "unterminated entity reference" you may use htmlentities() for escaping supplied value:
<?php
//...
$dom->createElement('name', htmlentities($text))
//...
?>