The DOMImplementation class

(PHP 5, PHP 7, PHP 8)

Introduction

The DOMImplementation class provides a number of methods for performing operations that are independent of any particular instance of the document object model.

Class synopsis

class DOMImplementation {

/* Methods */

public createDocument(?string $namespace = null, string $qualifiedName = "", ?DOMDocumentType $doctype = null): DOMDocument|false

public createDocumentType(string $qualifiedName, string $publicId = "", string $systemId = ""): DOMDocumentType|false

public hasFeature(string $feature, string $version): bool

}

DOMImplementation::__construct — Creates a new DOMImplementation object
DOMImplementation::createDocument — Creates a DOMDocument object of the specified type with its document element
DOMImplementation::createDocumentType — Creates an empty DOMDocumentType object
DOMImplementation::hasFeature — Test if the DOM implementation implements a specific feature

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User Contributed Notes 4 notes

down

LANGE.LUDO ¶

9 years ago

Ok got it working like a charm using "proxy pattern" with traits. The idea being declaring the common methods inside a "trait" in order for extended and registered Node Classes to have access even if not derived / child of the extended DOMNode…

Here a small snippet :
<?php
    namespace my;

    trait tNode
    {    // We need the magic method __get in order to add properties such as DOMNode->parentElement
        public function __get($name)
        {    if(property_exists($this, $name)){return $this->$name;}
            if(method_exists($this, $name)){return $this->$name();}
            throw new \ErrorException('my\\Node property \''.(string) $name.'\' not found…', 42, E_USER_WARNING);
        }

        // parentElement property definition
        private function parentElement()
        {    if($this->parentNode === null){return null;}
            if($this->parentNode->nodeType === XML_ELEMENT_NODE){return $this->parentNode;}
            return $this->parentNode->parentElement();
        }

        // JavaScript equivalent
        public function isEqualNode(\DOMNode $node){return $this->isSameNode($node);}
        public function compareDocumentPosition(\DOMNode $otherNode)
        {    if($this->ownerDocument !== $otherNode->ownerDocument){return DOCUMENT_POSITION_DISCONNECTED;}
            $c = strcmp($this->getNodePath(), $otherNode->getNodePath());
            if($c === 0){return 0;}
            else if($c < 0){return DOCUMENT_POSITION_FOLLOWING | ($c < -1 ? DOCUMENT_POSITION_CONTAINED_BY : 0);}
            return DOCUMENT_POSITION_PRECEDING | ($c > 1 ? DOCUMENT_POSITION_CONTAINS : 0);
        }
        public function contains(\DOMNode $otherNode){return ($this->compareDocumentPosition($otherNode) >= DOCUMENT_POSITION_CONTAINED_BY);}
    }

    class Document extends \DomDocument
    {    public function __construct($version=null, $encoding=null)
        {    parent::__construct($version, $encoding);
            $this->registerNodeClass('DOMNode', 'my\Node');
            $this->registerNodeClass('DOMElement', 'my\Element');
            $this->registerNodeClass('DOMDocument', 'my\Document');
            /* [...] */
        }
    }

    class Element extends \DOMElement
    {    use tNode;
        /* [...] */
    }

    class Node extends \DOMNode
    {    use tNode;
        /* [...] */
    }

?>

down

LANGE.LUDO ¶

9 years ago

From what I've seen you must "recode" the "createDocument" method in order to call your own object extension…

<?php
[...]
    public function createDocument($namespaceURI=null, $qualifiedName=null, DOMDocumentType $docType=null)
    {    $doc=new Document();
        $doc->appendChild(parent::createDocumentType('html'));
        $this->doc->appendChild($namespaceURI ? $this->doc->createElementNS($namespaceURI,$qualifiedName) : $this->doc->createElement($qualifiedName));
    return $doc;
    }
[...]
?>

Where I am struggling is extending the whole tree so that calling the customized Implementation method returns a whole extended tree…
Expected result : Implementation > Document > DOMDocument > Node > DOMNode
Actual result : Implementation > Document > DOMDocument > DOMNode :(

down

LANGE.LUDO ¶

9 years ago

Why not use the DOMImplementation to directly register your DOM Class extensions ?

<?php
namespace My;
class Implementation extends \DOMImplementation
{    private $doc;
    public function __construct(){return $this->createDocument();}
    public function __get($name){return $this->doc->{$name};}
    public function __set($name,$value){$this->doc->{$name}=$value;}
    public function __isset($name){return isset($this->doc->{$name});}
    public function __unset($name){return $this->doc->__unset($name);}
    public function __call($name,$args){return call_user_func_array(array($this->doc,$name),$args);}
    
    public function createDocument($namespaceURI=null,$qualifiedName=null,DOMDocumentType $docType=null)
    {    $this->doc=parent::createDocument($namespaceURI,$qualifiedName,$docType);
        $this->doc->xmlVersion='1.0';
        $this->doc->xmlEncoding='UTF-8';
        $this->doc->registerNodeClass('DOMDocument','My\Document');
        $this->doc->registerNodeClass('DOMDocumentFragment','My\DocumentFragment');
        $this->doc->registerNodeClass('DOMElement','My\Element');
        $this->doc->registerNodeClass('DOMComment','My\Comment');
        $this->doc->registerNodeClass('DOMNode','My\Node');
        /* …, …, … */
        return $this->doc;
    }
}
?>

down

-2

giorgio dot liscio at email dot it ¶

13 years ago

officially, the w3 specifies that the way to access dom interfaces is through this class

so if you use

$doc = new DOMDocument("1.0", "UTF-8");

use instead:

$x = new DOMImplementation();
$doc = $x->createDocument(NULL,"rootElementName");
$doc->xmlVersion="1.0";
$doc->xmlEncoding="UTF-8";

it is not required by php's implementation, but, probably, it is a good practice 

see:

http://w3.org/TR/DOM-Level-3-Core/core.html#DOMImplementation

http://w3.org/TR/DOM-Level-3-Core/core.html#DOMImplementationList

http://w3.org/TR/DOM-Level-3-Core/core.html#DOMImplementationSource

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The DOMImplementation class

Introduction

Class synopsis

Table of Contents

User Contributed Notes 4 notes