DOMImplementation::createDocumentType()

(PHP 5, PHP 7)

Creates an empty DOMDocumentType object

说明

publicDOMImplementation::createDocumentType([string $qualifiedName= NULL[,string $publicId= NULL[,string $systemId= NULL]]]): DOMDocumentType

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

参数

$qualifiedName: The qualified name of the document type to create.
$publicId: The external subset public identifier.
$systemId: The external subset system identifier.

返回值

A new DOMDocumentType node with itsownerDocumentset to NULL.

错误／异常

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

此方法可以被静态调用,但会抛出一个E_STRICT错误。

范例

Example #1 Creating a document with an attached DTD

<?php
// 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
$dom->appendChild($element);
// Retrieve and print the document
echo $dom->saveXML();
?>

以上例程会输出：

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

参见

DOMImplementation::createDocument() Creates a DOMDocument object of the specified type with its document element

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 ( http://php.net/manual/en/wrappers.data.php ) as a work-around:
<?php
// 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.