XML: Save several child node's values into php array

Question

How can I retrieve all <ASIN>..</ASIN> values of this xml and save them to a php variable/array?

I tried $result=$xml->xpath('//ASIN'); but this gives me array(0) { } as a browser output. Thank you for your help! I appreciate it very much!

This is my xml file:

    <?xml version="1.0" ?>
      <ItemLookupResponse xmlns="http://webservices.amazon.com/AWSECommerceService/2011-08-01">
      <OperationRequest>
        <RequestId>...</RequestId>
      <Arguments>
       <Argument Name="region" Value="de"></Argument>
       <Argument Name="ItemId" Value="B007ZXLRVQ"></Argument>
       <Argument Name="Operation" Value="ItemLookup"></Argument>
       <Argument Name="Service" Value="AWSECommerceService"></Argument>
       <Argument Name="AWSAccessKeyId" Value="...."></Argument>
       <Argument Name="Timestamp" Value="2012-11-27T12:52:41Z"></Argument>
       <Argument Name="Signature" Value="...."></Argument>
       <Argument Name="ResponseGroup" Value="Similarities"></Argument>
       <Argument Name="AssociateTag" Value="..."></Argument>
       <Argument Name="Version" Value="2009-10-01"></Argument>
     </Arguments>
    <RequestProcessingTime>0.0216670000000000</RequestProcessingTime>
    </OperationRequest>
    <Items>
       <Request>
         <IsValid>True</IsValid>
         <ItemLookupRequest>
           <IdType>ASIN</IdType>
           <ItemId>B007ZXLRVQ</ItemId>
           <ResponseGroup>Similarities</ResponseGroup>
           <VariationPage>All</VariationPage>
         </ItemLookupRequest>
      </Request>
     <Item>
      <ASIN>B007ZXLRVQ</ASIN>
      <SimilarProducts><SimilarProduct><ASIN>B007Y6DS84</ASIN>
       <Title>Brita 040 147 Starterpaket Marella Cool, weiß</Title>
      </SimilarProduct>
      <SimilarProduct>
       <ASIN>B0018K7EMI</ASIN>
       <Title>Trinkflasche 1,0 Liter für gefiltertes Wasser</Title>
      </SimilarProduct>
      <SimilarProduct>
       <ASIN>B000QG7AJM</ASIN>
       <Title>Brita Filterkartuschen Maxtra Pack 4 (lim. Edition)</Title>
      </SimilarProduct>
      <SimilarProduct>
       <ASIN>B001T9N51M</ASIN>
       <Title>Brita Filterkartuschen Maxtra Pack 12 (lim. Edition)</Title>
      </SimilarProduct>
      <SimilarProduct>
       <ASIN>B001ET6CNU</ASIN>
       <Title>wuta kamille 82158 Herbacin Handcreme + Glyzerin Dose 75 ml, Fünferpack</Title>
     </SimilarProduct>
    </SimilarProducts>
   </Item>
  </Items>
 </ItemLookupResponse>

Answer 1

Because of Namespace you're not able to execute XPath query directly. Read the full details solution here

Still I am providing here little bit code which can help you.

$asins = simplexml_load_file('asin.xml');
if(count($asins)):
    //alternate way other than registring NameSpace
    //$asin = $asins->xpath("//*[local-name() = 'ASIN']");

    $asins->registerXPathNamespace('prefix', 'http://webservices.amazon.com/AWSECommerceService/2011-08-01');
    $asin = $asins->xpath("//prefix:ASIN");
    echo "<pre>";print_r($asin);
endif;

Now you will see array off ASIN element like below

Array
(
    [0] => SimpleXMLElement Object
        (
            [0] => B007ZXLRVQ
        )

    [1] => SimpleXMLElement Object
        (
            [0] => B007Y6DS84
        )

    [2] => SimpleXMLElement Object
        (
            [0] => B0018K7EMI
        )

    [3] => SimpleXMLElement Object
        (
            [0] => B000QG7AJM
        )

    [4] => SimpleXMLElement Object
        (
            [0] => B001T9N51M
        )

    [5] => SimpleXMLElement Object
        (
            [0] => B001ET6CNU
        )

)