PHP array to get single valid XML - php

Question

I use the following api to get product info from amazon.
It uses a single value for variable $asin to get the data and print it as xml. It works fine, but this is only for one product at a time…
I would like instead of a single variable $asin, to use an array with multiple values and print to one single xml.
I tried to use foreach, but I get en xml declaration for every loop.
Where do I need to use foreach in my code? Thanks for the help.
<?php
// Region code and Product ASIN
$response = getAmazonPrice("com", "B00KQPGRRE");
function getAmazonPrice($region, $asin) {
$xml = aws_signed_request($region, array(
"Operation" => "ItemLookup",
"ItemId" => $asin,
"IncludeReviewsSummary" => False,
"ResponseGroup" => "Medium,OfferSummary",
));
$item = $xml->Items->Item;
$title = htmlentities((string) $item->ItemAttributes->Title);
$url = htmlentities((string) $item->DetailPageURL);
$image = htmlentities((string) $item->MediumImage->URL);
$price = htmlentities((string) $item->OfferSummary->LowestNewPrice->Amount);
$code = htmlentities((string) $item->OfferSummary->LowestNewPrice->CurrencyCode);
$qty = htmlentities((string) $item->OfferSummary->TotalNew);
if ($qty !== "0") {
$response = array(
"code" => $code,
"price" => number_format((float) ($price / 100), 2, '.', ''),
"image" => $image,
"url" => $url,
"title" => $title
);
}
return $response;
}
function getPage($url) {
$curl = curl_init($url);
curl_setopt($curl, CURLOPT_FAILONERROR, true);
curl_setopt($curl, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, false);
curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
$html = curl_exec($curl);
curl_close($curl);
return $html;
}
function aws_signed_request($region, $params) {
$public_key = "PUBLIC_KEY";
$private_key = "PRIVATE_KEY";
$method = "GET";
$host = "ecs.amazonaws." . $region;
$host = "webservices.amazon." . $region;
$uri = "/onca/xml";
$params["Service"] = "AWSECommerceService";
$params["AssociateTag"] = "affiliate-20"; // Put your Affiliate Code here
$params["AWSAccessKeyId"] = $public_key;
$params["Timestamp"] = gmdate("Y-m-d\TH:i:s\Z");
$params["Version"] = "2011-08-01";
ksort($params);
$canonicalized_query = array();
foreach ($params as $param => $value) {
$param = str_replace("%7E", "~", rawurlencode($param));
$value = str_replace("%7E", "~", rawurlencode($value));
$canonicalized_query[] = $param . "=" . $value;
}
$canonicalized_query = implode("&", $canonicalized_query);
$string_to_sign = $method . "\n" . $host . "\n" . $uri . "\n" . $canonicalized_query;
$signature = base64_encode(hash_hmac("sha256", $string_to_sign, $private_key, True));
$signature = str_replace("%7E", "~", rawurlencode($signature));
$request = "http://" . $host . $uri . "?" . $canonicalized_query . "&Signature=" . $signature;
$response = getPage($request);
var_dump($response);
$pxml = #simplexml_load_string($response);
if ($pxml === False) {
return False;// no xml
} else {
return $pxml;
}
}
?>
I used the following code to have multiple values:
<?php
// Region code and Product ASIN
$array = array("B00PXRRB2U","B00F90P9R0","B005OJU3K4");
foreach ($array as $asin) {
$response = getAmazonPrice("com", $asin);
}
function getAmazonPrice($region, $asin) {
$xml = aws_signed_request($region, array(
"Operation" => "ItemLookup",
"ItemId" => $asin,
"IncludeReviewsSummary" => False,
"ResponseGroup" => "Medium,OfferSummary",
));
The result is:

Answer 1

Amazon allows the lookup of up to 10 items with a single request. Its service expects the ASINs to be passed as a string separated by commas.
So you could try the following code (please note I didn't actually try it because I don't have credentials but I used it like that before and it worked):
$array = array("B00PXRRB2U","B00F90P9R0","B005OJU3K4");
$xml = aws_signed_request('com', array(
"Operation" => "ItemLookup",
"ItemId" => join(', ', $array),
"IncludeReviewsSummary" => False,
"ResponseGroup" => "Medium,OfferSummary",
));
And then I think what you're looking for will be in $xml->Items but you'd better double check that.