xpath search for a php variable - php

Question

I am trying to search for a php variable in an xml file using xpath, but failing miserably. It works with a hard coded value, so I am nearly there..
<visitors>
<detail>
<id>876867</id>
<name>Bob McHaggis</name>
<email>bob#gmail.com</email>
</detail>
<detail>
<id>897987</id>
<name>Mark McBob</name>
<email>mark#gmail.com</email>
</detail>
</visitors>
<?php $sxe = simplexml_load_file("/CaptivePortal/visitors.xml");
foreach($sxe->xpath('//visitors/detail') as $item){
$row = simplexml_load_string($item->asXML());
$v = $row->xpath('//id[. ="'.$_COOKIE["judsons"].'"]');
} echo $v[0]; ?>
This works great checks for an id against the id stored in the cookie. But based on that value being found how do I access the name and email for the key matched?
Found & matched: 897987
I want to echo the name and email to, so based on that is Mark McBob & mark#gmail.com

Answer 1

My initial advice would be to take a good few minutes to (re-)read through the SimpleXML Basic Usage page in the PHP manual.
For selecting a single item within the XML file, there is no need at all to loop over anything. The example code below, and why it is different from yours, should become clear after familiarising yourself with the page mentioned above.
<?php
$search_id = (int) $_COOKIE["judsons"];
$visitors = simplexml_load_file("/CaptivePortal/visitors.xml");
$details = $visitors->xpath("detail[id='$search_id']");
if (empty($details)) {
echo "No details found for '$search_id'.";
} else {
$detail = $details[0];
$name = (string) $detail->name;
$email = (string) $detail->email;
echo "$name's email is $email";
}
The idea above is that $details will be an array containing hopefully just one <detail> element. It could be an empty array if no <detail> was found with the specified <id>, which is what the if(empty(…)) checks for. If the $details array is not empty, we're really only interested in the first one ($details[0]).
To access the information available within the <detail>, as explained on the "basic usage" page, the elements can be accessed with normal object property syntax ($detail->name). Doing so returns an object for that item (e.g. the <name>), so to get at the value as a string the object is type cast using (string).

Answer 2

You're actually doing quite a bit you don't need to there. For one thing, you don't need the loop. For another, inside your loop, you convert the context XML into a string (::asXML()), then convert it back into XML (simplexml_load_string()).
All you need is:
$xml = "<visitors><detail><id>876867</id><name>Bob McHaggis</name><email>bob#gmail.com</email></detail><detail><id>897987</id><name>Mark McBob</name><email>mark#gmail.com</email></detail></visitors>";
$sxe = simplexml_load_string($xml);
$row = $sxe->xpath('detail[id = '.$_COOKIE["judsons"].']');
That gets you the row. To extract part of it:
$name = $row[0]->xpath('name');
echo $name[0]; //Mark McBob