Question

I have several identical elements with different attributes that I’m accessing with SimpleXML:

<data>     <seg id='A1'/>     <seg id='A5'/>     <seg id='A12'/>     <seg id='A29'/>     <seg id='A30'/> </data> 

I need to remove a specific seg element, with an id of ‘A12’, how can I do this? I’ve tried looping through the seg elements and unsetting the specific one, but this doesn’t work, the elements remain.

foreach($doc->seg as $seg) {     if($seg['id'] == 'A12')     {         unset($seg);     } } 

Answer 1

While SimpleXML provides a way to remove XML nodes, its modification capabilities are somewhat limited. One other solution is to resort to using the DOM extension. dom_import_simplexml() will help you with converting your SimpleXMLElement into a DOMElement.

Just some example code (tested with PHP 5.2.5):

$data='<data>     <seg id='A1'/>     <seg id='A5'/>     <seg id='A12'/>     <seg id='A29'/>     <seg id='A30'/> </data>'; $doc=new SimpleXMLElement($data); foreach($doc->seg as $seg) {     if($seg['id'] == 'A12') {         $dom=dom_import_simplexml($seg);         $dom->parentNode->removeChild($dom);     } } echo $doc->asXml(); 

outputs

<?xml version='1.0'?> <data><seg id='A1'/><seg id='A5'/><seg id='A29'/><seg id='A30'/></data> 

By the way: selecting specific nodes is much more simple when you use XPath (SimpleXMLElement->xpath):

$segs=$doc->xpath('//seq[@id='A12']'); if (count($segs)>=1) {     $seg=$segs[0]; } // same deletion procedure as above