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This document uses PHP Chinese website manual Release
(PHP 5, PHP 7)
dom_import_simplexml — Gets a DOMElement object from a SimpleXMLElement object
$node
)
This function takes the node node
of class
SimpleXML and makes it into a
DOMElement node. This new object can then be used
as a native DOMElement node.
node
The SimpleXMLElement node.
The DOMElement node added or FALSE
if any errors occur.
Example #1 Import SimpleXML into DOM with dom_import_simplexml()
<?php
$sxe = simplexml_load_string ( '<books><book><title>blah</title></book></books>' );
if ( $sxe === false ) {
echo 'Error while parsing the document' ;
exit;
}
$dom_sxe = dom_import_simplexml ( $sxe );
if (! $dom_sxe ) {
echo 'Error while converting XML' ;
exit;
}
$dom = new DOMDocument ( '1.0' );
$dom_sxe = $dom -> importNode ( $dom_sxe , true );
$dom_sxe = $dom -> appendChild ( $dom_sxe );
echo $dom -> saveXML ();
?>
[#1] Jeff M [2009-03-06 01:09:54]
SimpleXML is an 'Object Mapping XML API'. It is not DOM, per se. SimpleXML converts the XML elements into PHP's native data types.
The dom_import_simplexml and simplexml_import_dom functions do *not* create separate copies of the original object. You are free to use the methods of either or both interchangeably, since the underlying instance is the same.
<?php
// initialize a simplexml object
$sxe = simplexml_load_string('<root/>');
// get a dom interface on the simplexml object
$dom = dom_import_simplexml($sxe);
// dom adds a new element under the root
$element = $dom->appendChild(new DOMElement('dom_element'));
// dom adds an attribute on the new element
$element->setAttribute('creator', 'dom');
// simplexml adds an attribute on the dom element
$sxe->dom_element['sxe_attribute'] = 'added by simplexml';
// simplexml adds a new element under the root
$element = $sxe->addChild('sxe_element');
// simplexml adds an attribute on the new element
$element['creator'] = 'simplexml';
// dom finds the simplexml element (via DOMNodeList->index)
$element = $dom->getElementsByTagName('sxe_element')->item(0);
// dom adds an attribute on the simplexml element
$element->setAttribute('dom_attribute', 'added by dom');
echo ('<pre>');
print_r($sxe);
echo ('</pre>');
?>
Outputs:
SimpleXMLElement Object
(
[dom_element] => SimpleXMLElement Object
(
[@attributes] => Array
(
[creator] => dom
[sxe_attribute] => added by simplexml
)
)
[sxe_element] => SimpleXMLElement Object
(
[@attributes] => Array
(
[creator] => simplexml
[dom_attribute] => added by dom
)
)
)
What this illustrates is that both interfaces are operating on the same underlying object instance. Also, when you dom_import_simplexml, you can create and add new elements without reference to an ownerDocument (or documentElement).
So passing a SimpleXMLElement to another method does not mean the recipient is limited to using SimpleXML methods.
Hey Presto! Your telescope has become a pair of binoculars!
[#2] crescentfreshpot at yahoo dot com [2007-12-12 12:22:45]
justinpatrin at php dot net:
> To get a proper DOM document (which you need to do most things) you need...
No you don't. Just do:
<?php
$dom = dom_import_simplexml($xml)->ownerDocument;
?>
[#3] justinpatrin at php dot net [2006-06-01 21:44:19]
I've found that newer versions of PHP5 require some special syntax in order to properly convert between SimpleXML and DOM. It's not as easy as calling dom_import_simplexml() with a SimpleXML node. To get a proper DOM document (which you need to do most things) you need:
<?php
//$xml is a SimpleXML instance
$domnode = dom_import_simplexml($xml);
$dom = new DOMDocument();
$domnode = $dom->importNode($domnode, true);
$dom->appendChild($domnode);
?>
Switching back, though, is, well...simple.
<?php
//$dom is a DOMDocument instance
$xml = simplexml_import_dom($dom);
?>