Converting amazon MWS scratchpad queries to API calls - php

Question

I want to know if there is a way to convert my Amazon MWS scratchpad queries to an API call
e.g. when using the MWS scratchpad I'm given a String to sign
"mws.amazonservices.co.uk"
."/Products/2011-10-01"
."AWSAccessKeyId=xxx&Action=ListMatchingProducts"
."&MarketplaceId=xxx&Query=star%20wars&SellerId=xxx"
."&SignatureMethod=HmacSHA256&SignatureVersion=2
."&Timestamp=2012-07-27T18%3A59%3A30Z&Version=2011-10-01
After spending days trying to get Amazons order API to work I have given up and have been hoping that the following function would return an xml string...but with no luck
function callAmazon(){
$apicall = "mws.amazonservices.co.uk"
."/Products/2011-10-01"
."AWSAccessKeyId=xxx&Action=ListMatchingProducts"
."&MarketplaceId=xxx&Query=star%20wars&SellerId=xxx"
."&SignatureMethod=HmacSHA256&SignatureVersion=2
."&Timestamp=2012-07-27T18%3A59%3A30Z&Version=2011-10-01
$resp = simplexml_load_file($apicall); //make the call
}
Does anyone have any possible suggestions?

Answer 1

I struggled with this for a long time as well, here is how I solved it for the Products API:
<?php
require_once('.config.inc.php');
$base_url = "https://mws.amazonservices.com/Products/2011-10-01";
$method = "POST";
$host = "mws.amazonservices.com";
$uri = "/Products/2011-10-01";
function amazon_xml($searchTerm) {
$params = array(
'AWSAccessKeyId' => AWS_ACCESS_KEY_ID,
'Action' => "ListMatchingProducts",
'SellerId' => MERCHANT_ID,
'SignatureMethod' => "HmacSHA256",
'SignatureVersion' => "2",
'Timestamp'=> gmdate("Y-m-d\TH:i:s.\\0\\0\\0\\Z", time()),
'Version'=> "2011-10-01",
'MarketplaceId' => MARKETPLACE_ID,
'Query' => $searchTerm,
'QueryContextId' => "Books");
// Sort the URL parameters
$url_parts = array();
foreach(array_keys($params) as $key)
$url_parts[] = $key . "=" . str_replace('%7E', '~', rawurlencode($params[$key]));
sort($url_parts);
// Construct the string to sign
$url_string = implode("&", $url_parts);
$string_to_sign = "GET\nmws.amazonservices.com\n/Products/2011-10-01\n" . $url_string;
// Sign the request
$signature = hash_hmac("sha256", $string_to_sign, AWS_SECRET_ACCESS_KEY, TRUE);
// Base64 encode the signature and make it URL safe
$signature = urlencode(base64_encode($signature));
$url = "https://mws.amazonservices.com/Products/2011-10-01" . '?' . $url_string . "&Signature=" . $signature;
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,$url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_TIMEOUT, 15);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
$response = curl_exec($ch);
$parsed_xml = simplexml_load_string($response);
return ($parsed_xml);
}
?>
The .inc.config.php file contains my access key, secret key etc.
EDIT:
$searchterm is the isbn I am passing from my form.

Answer 2

You need to actually CALL the API. The string you are using doesn't specify the http:// portion of the URL.

Answer 3

I had a little trouble with this code, I had it working when uploaded to a hosted web server but not when running local using windows and xampp.
If you are having problems, try adding this to the end of the curl-setopt block.
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
btw you also need to modify your php.ini file in the xampp folder to enable curl.