PHP - 从xml获取值

Question

I have a some problem with get value from xml.

XML look like

<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="http://crd.gov.pl/xml/schematy/UPO/2008/05/09/UPO.xsl"?>
<pos:Document xmlns:pos="SOMEURL"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
   <pos:DescribeDoc/>
   <pos:UPD>
      <pos:IdDoc>procotol-UPD2198338</pos:IdDoc>
      <pos:IdCases>221872</pos:IdCases>
      <pos:additionalInfo TypeInfo="Source">Some string</pos:additionalInfo>
   </pos:UPD>
...

I general try to get to pos:IdCases. I try this code:

$domContent = new SimpleXMLElement(((string) $content), LIBXML_COMPACT);
$test = $domContent->xpath('/pos:Document/pos:UPD/*');
foreach($test as $node){
    print_r($node)
}

I get a some object such as

SimpleXMLElement Object
(
     [0] => procotol-UPD2198338
)

SimpleXMLElement Object
(
    [0] => 221872
)

SimpleXMLElement Object
(
    [@attributes] => Array
        (
            [TypeInfo] => Source
        )

    [0] => Some string
)

But I must get to pos:IdCases. I can't use index [1] because order can change.

My question is: How can I get to value in node: pos:IdCases I can't add id or another info to node because this xml was signed (XADES).

Can you give me some advice? Thanks for help

Answer 1

Simply change the XPath to match the <Pos:IdCases/> node:

$test = $domContent->xpath('/pos:Document/pos:UPD/pos:IdCases');