XML Request and Response with PHP for USPS Rate Calculator

I have been trying to build a USPS Rate Calculator for a site, but unfortunately the test url from USPS does not seem to work. In any case, my code does not return anything at the moment, not even the error message about the url...

Would you take a look to see if I am doing the right thing? I get a bit lost with XML on PHP...

CODE:

$zip = 90002;
$pounds = 0.1;

function USPSParcelRate($pounds,$zip) {
$url = "https://secure.shippingapis.com/ShippingAPITest.dll";
curl_setopt($ch, CURLOPT_URL,$url);
curl_setopt($ch, CURLOPT_HEADER, 1);
curl_setopt($ch,CURLOPT_RETURNTRANSFER,1);
// parameters to post
curl_setopt($ch, CURLOPT_POST, 1);
$xml = "API=RateV4&XML=<RateV4Request USERID='USERNAME' >
<Revision/>
     <Package ID='1ST'>
          <Service>PRIORITY</Service>
          <ZipOrigination>10025</ZipOrigination>
          <ZipDestination>$zip</ZipDestination>
          <Pounds>$pounds</Pounds>
          <Ounces>0</Ounces>
          <Container></Container>
          <Size>REGULAR</Size>
          <Width></Width>
          <Length></Length>
          <Height></Height>
          <Girth></Girth>
     </Package>
</RateV4Request>";
// send the POST values to USPS
curl_setopt($ch, CURLOPT_POSTFIELDS,$xml);
    $result = curl_exec($ch);
    $data = strstr($result, '<?');
    $xml_parser = xml_parser_create();
    xml_parse_into_struct($xml_parser, $data, $vals, $index);
    xml_parser_free($xml_parser);
    $params = array();
    $level = array();
    echo "TEST";
    foreach ($vals as $xml_elem) {
        if ($xml_elem['type'] == 'open') {
            if (array_key_exists('attributes',$xml_elem)) {
                list($level[$xml_elem['level']],$extra) = array_values($xml_elem['attributes']);
            } else {
            $level[$xml_elem['level']] = $xml_elem['tag'];
            }
        }
        if ($xml_elem['type'] == 'complete') {
        $start_level = 1;
        $php_stmt = '$params';
        while($start_level < $xml_elem['level']) {
            $php_stmt .= '[$level['.$start_level.']]';
            $start_level++;
        }
        $php_stmt .= '[$xml_elem[\'tag\']] = $xml_elem[\'value\'];';
        eval($php_stmt);
        }
    }
    curl_close($ch);
    echo '<pre>'; print_r($params); echo'</pre>'; // Uncomment to see xml tags
    return $params['RateV4Response']['1ST']['1']['RATE'];
}

USPSParcelRate($pounds,$zip)

Solution

You are missing the curl_init() function since $ch is not defined

$ch = curl_init();

Also you are not printing the response:

**echo** USPSParcelRate($pounds,$zip);

Lastly, you can print the response from curl, change:

echo "TEST";

to:

print "RESPONSE: $result";

I'm getting that RateV4 is not authorized, where is RateV4 coming from?

TEST HTTP/1.1 200 Connection established

HTTP/1.1 200 OK
Connection: close
Date: Mon, 10 Jun 2013 17:16:17 GMT
Server: Microsoft-IIS/6.0
X-Powered-By: ASP.NET

<Error>
    <Number>80040b1a</Number>
    <Description>API Authorization failure. RateV4 is not a valid API name for this protocol.</Description>
    <Source>UspsCom::DoAuth</Source>
</Error>

Hope this at least helps with debugging..