VAT Number Validation Function Not Working - php

Question

I'm trying to write a vat number validation function which checks a vat number to see if it's valid.
Currently i've got this
function tep_check_vatnum($countries_id, $vatnum) {
$country = tep_get_countries_with_iso_codes($countries_id);
$iso = $country['countries_iso_code_2'];
if($iso == "GB"){
return false;
} else {
$url = "http://isvat.appspot.com/$iso/$vatnum";
$session = curl_init();
curl_setopt($session, CURLOPT_URL, $url);
// curl_setopt($session, CURLOPT_HTTPGET, 1);
// curl_setopt($session, CURLOPT_HEADER, false);
// curl_setopt($session, CURLOPT_HTTPHEADER, array('Accept: application/xml', 'Content-Type: application/xml'));
curl_setopt($session, CURLOPT_RETURNTRANSFER, true);
$response = curl_exec($session);
//echo "<!-- NOTE:" . $response . "-->";
curl_close($session);
if($response == "true"){
return true;
} else {
return false;
}
}
}
The service i'm using http://isvat.appspot.com is working, But it's not working.
EDIT
Hmm no luck. By not working, it keeps giving me an error saying the vat number isn't valid. On the create account form i've got this code.
<?php echo tep_draw_input_field('vatnum', '', 'class="input"') . ' ' . (tep_not_null(ENTRY_COMPANY_TEXT) ? '<span class="inputRequirement">' . ENTRY_COMPANY_TEXT . '</span>': ''); ?>
if (is_numeric($country) == false) {
$error = true;
$messageStack->add('create_account', ENTRY_COUNTRY_ERROR);
} else {
if(strlen($vatnum) != 0){
if(is_numeric($vatnum) == false || tep_check_vatnum($country, $vatnum) == false){
$error = true;
$messageStack->add('create_account', "VAT Number is not a valid EU, non-UK VAT no.");
}
}

Answer 1

I guess there might be a problem invoking cURL. The good news is, you probably don't need to. ;) Give this a try:
function tep_check_vatnum($countries_id, $vatnum) {
$country = tep_get_countries_with_iso_codes($countries_id);
$iso = $country['countries_iso_code_2'];
if($iso == "GB"){
return false;
} else {
$url = "http://isvat.appspot.com/$iso/$vatnum";
$context = stream_context_create(array(
'http' => array(
'proxy' => 'http://PROXY_IP:PROXY_PORT'
),
));
$fp = fopen($url,'r',$context);
$response = fgets($fp);
fclose($fp);
//echo "<!-- NOTE:" . $response . "-->";
if($response == "true"){
return true;
} else {
return false;
}
}
}
It should work even if you don't have the cURL extension enabled.
Edit: As Michas said, it is difficult to find the problem with your original code without knowing what you mean by "not working". You could try to get some more information about the problem by stating error_reporting(E_ALL) or curl_error($session).
Possible causes: cURL is not installed or configured correctly or a proxy or firewall is blocking your request. While the code I suggested would eliminate the first one, the second one might also apply using it, depending on your settings.
Edit 2: Added simple proxy configuration