CascadiaPHP 2024


(PHP 5, PHP 7, PHP 8)

DOMImplementation::createDocumentType Creates an empty DOMDocumentType object


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

Creates an empty DOMDocumentType object. Entity declarations and notations are not made available. Entity reference expansions and default attribute additions do not occur.



The qualified name of the document type to create.


The external subset public identifier.


The external subset system identifier.

Return Values

A new DOMDocumentType node with its ownerDocument set to null or false on error.



Raised if there is an error with the namespace, as determined by qualifiedName.


Version Description
8.0.0 Calling this function statically will now throw an Error. Previously, an E_DEPRECATED was raised.


Example #1 Creating a document with an attached DTD


// Creates an instance of the DOMImplementation class
$imp = new DOMImplementation;

// Creates a DOMDocumentType instance
$dtd = $imp->createDocumentType('graph', '', 'graph.dtd');

// Creates a DOMDocument instance
$dom = $imp->createDocument("", "", $dtd);

// Set other properties
$dom->encoding = 'UTF-8';
$dom->standalone = false;

// Create an empty element
$element = $dom->createElement('graph');

// Append the element

// Retrieve and print the document
echo $dom->saveXML();


The above example will output:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE graph SYSTEM "graph.dtd">

See Also

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User Contributed Notes 1 note

until-all-bytes-are-free at example dot org
13 years ago
I had problems to use a DTD from a file. It needed to be resolved relatively and it contained characters that made DomDocument failed to resolve the file.

Encoding and an absolute filename did not help much. So I used the data:// streamwrapper ( ) as a work-around:


// relative or absolute filename
$path = '...';

// convert file contents into a filename
$data = file_get_contents($path);
$systemId = 'data://text/plain;base64,'.base64_encode($data);

// ...

// Creates a DOMDocumentType instance
$dtd = $aImp->createDocumentType('qualified name', '', $systemId);


Works like a charm.
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