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    DOMDocument::registerNodeClass

    (PHP 5 >= 5.2.0, PHP 7, PHP 8)

    DOMDocument::registerNodeClass — Register extended class used to create base node type

    Description

    public DOMDocument::registerNodeClass(string $baseClass, ?string $extendedClass): bool

    This method allows you to register your own extended DOM class to be used afterward by the PHP DOM extension.

    This method is not part of the DOM standard.

    Caution

    The constructor of the objects of the registered node classes is not called.

    Parameters

    baseClass

    The DOM class that you want to extend. You can find a list of these classes in the chapter introduction.

    extendedClass

    Your extended class name. If null is provided, any previously registered class extending baseClass will be removed.

    Return Values

    Returns true on success or false on failure.

    Examples

    Example #1 Adding a new method to DOMElement to ease our code

    <?php

    class myElement extends DOMElement {
    function     appendElement($name) {
    return     $this->appendChild(new myElement($name));
    }
    }

    class     myDocument extends DOMDocument {
    function     setRoot($name) {
    return     $this->appendChild(new myElement($name));
    }
    }

    $doc = new myDocument();
    $doc->registerNodeClass('DOMElement', 'myElement');

    // From now on, adding an element to another costs only one method call !
    $root = $doc->setRoot('root');
    $child = $root->appendElement('child');
    $child->setAttribute('foo', 'bar');

    echo     $doc->saveXML();

    ?>

    The above example will output:

    <?xml version="1.0"?>
<root><child foo="bar"/></root>

    Example #2 Retrieving elements as custom class

    <?php
    class myElement extends DOMElement {
    public function     __toString() {
    return     $this->nodeValue;
    }
    }

    $doc = new DOMDocument;
    $doc->loadXML("<root><element><child>text in child</child></element></root>");
    $doc->registerNodeClass("DOMElement", "myElement");

    $element = $doc->getElementsByTagName("child")->item(0);
    var_dump(get_class($element));

    // And take advantage of the __toString method..
    echo $element;
    ?>

    The above example will output:

    string(9) "myElement"
text in child

    Example #3 Retrieving owner document

    When instantiating a custom DOMDocument the ownerDocument property will refer to the instantiated class. However, if all references to that class are removed, it will be destroyed and new DOMDocument will be created instead. For that reason you might use DOMDocument::registerNodeClass() with DOMDocument

    <?php
    class MyDOMDocument extends DOMDocument {
    }

    class     MyOtherDOMDocument extends DOMDocument {
    }

    // Create MyDOMDocument with some XML
    $doc = new MyDOMDocument;
    $doc->loadXML("<root><element><child>text in child</child></element></root>");

    $child = $doc->getElementsByTagName("child")->item(0);

    // The current owner of the node is MyDOMDocument
    var_dump(get_class($child->ownerDocument));
    // MyDOMDocument is destroyed
    unset($doc);
    // And new DOMDocument instance is created
    var_dump(get_class($child->ownerDocument));

    // Import a node from MyDOMDocument
    $newdoc = new MyOtherDOMDocument;
    $child = $newdoc->importNode($child);

    // Register custom DOMDocument
    $newdoc->registerNodeClass("DOMDocument", "MyOtherDOMDocument");

    var_dump(get_class($child->ownerDocument));
    unset(    $doc);
    // New MyOtherDOMDocument is created
    var_dump(get_class($child->ownerDocument));
    ?>

    The above example will output:

    string(13) "MyDOMDocument"
string(11) "DOMDocument"
string(18) "MyOtherDOMDocument"
string(18) "MyOtherDOMDocument"

    Example #4 Custom objects are transient

    Caution

    Objects of the registered node classes are transient, i.e. they are destroyed when they are no longer referenced from PHP code, and recreated when being retrieved again. That implies that custom property values will be lost after recreation.

    <?php
    class MyDOMElement extends DOMElement
    {
    public     $myProp = 'default value';
    }

    $doc = new DOMDocument();
    $doc->registerNodeClass('DOMElement', 'MyDOMElement');

    $node = $doc->createElement('a');
    $node->myProp = 'modified value';
    $doc->appendChild($node);

    echo     $doc->childNodes[0]->myProp, PHP_EOL;
    unset(    $node);
    echo     $doc->childNodes[0]->myProp, PHP_EOL;
    ?>

    The above example will output:

    modified value
default value

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    User Contributed Notes 2 notes

    up
    4
    crh3675 at gmail dot com
    15 years ago
    Creating innerHTML and outerHTML

    <?php

    class DOMHTMLElement extends DOMElement
    {
        function     __construct() { parent::__construct();}
       
        public function     innerHTML()
        {
                $doc = new DOMDocument();
          foreach (    $this->childNodes as $child){
                  $doc->appendChild($doc->importNode($child, true));
            }
                $content = $doc->saveHTML();
            return     $content;
        }
       
        public function     outerHTML()
        {
                $doc = new DOMDocument();
                $doc->appendChild($doc->importNode($this, true));
                $content = $doc->saveHTML();
            return     $content;
        }
    }

    $dom = DOMDocument::loadHTMLFile($file);
    $dom->registerNodeClass('DOMElement','DOMHTMLElement');
               
    if(    $dom)
    {
            $xpath = new DOMXpath($dom);   
            $regions = $xpath->query("//*[contains(@class, 'editable')]");   
            $content = '';
       
        foreach(    $regions as $region){
                $content .= $region->outerHTML();
        }   
       
        return     $content;
       
    }else{               
        throw new     Exception('Cannot parse HTML.  Please verify the syntax is correct.');
    }
    ?>
    up
    1
    arnold at adaniels dot nl
    15 years ago
    Note than save and saveXML are not affected by __toString().
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