Amazon’s API is a good one. It is well documented API that is unbeatable when building an ecommerce site. Here’s a simple PHP class to handle your Amazon requests.

The code

config.php

This doesn’t have to go in config.php – it can go anywhere. Preferably, put it with other configuration values for your script.

<?php

	// This would go in your configuration file

	define( 'AMAZON_ASSOC_TAG', '' );
	define( 'AMAZON_ACCESS_KEY', '' );
	define( 'AMAZON_SECRET_KEY', '' ); // This isn't required for this simple API
	define( 'AMAZON_REQUEST_URL', 'http://ecs.amazonaws.com/onca/xml?Service=AWSECommerceService&Version=2007-07-16' ); 

?>

If you are using a different format for configuration (not constants), it should be pretty easy to modify things to use that format.

amazon.php

Here’s the handler class. It’s a simple one. I’ll explain how to use it after.

<?php

	class AmazonHandler {

		var $pubKey, $secKey, $requestURL;

		function __construct() {

			$this->assocTag = AMAZON_ASSOC_TAG;
			$this->pubKey = AMAZON_ACCESS_KEY;
			$this->secKey = AMAZON_SECRET_ACCCESS_KEY;

			$this->requestURL = AMAZON_REQUEST_URL;

		}

		function request( $operation, $data ) {

			$url = "{$this->requestURL}&Operation={$operation}&AWSAccessKeyId={$this->pubKey}&AssociateTag={$this->assocTag}" . $this->buildData( $data );

			$response = @file_get_contents( $url );

			$xml = simplexml_load_string( $response );

			return $xml;

		}

		function buildData( $data ) {

			$return = NULL;
			$i = 0;
			$t = count( $data );

			foreach( $data as $k => $v ) {

				$k = urlencode( $k );
				$v = urlencode( $v );

				$return .= "&{$k}={$v}";

			}

			return $return;

		}

	}

?>

An explanation

This handler is quite simple. It only offers the request() method to request data from Amazon. Here’s a few examples:

<?php

	$am = new AmazonHandler;

	$nodes = $am->request( 'BrowseNodeLookup', array(
		'BrowseNodeId' => 1
	) );

	$items = $am->request( 'ItemSearch', array(
		'BrowseNode' => 1,
		'SearchIndex' => 'Books',
		'Keywords' => 'Harry Potter',
		'ItemPage' => 1
	) );

?>

The request() method returns a SimpleXML object.

You can learn about all of the API methods here. (Look under API Reference > Operations.) You will need to know the different API operations and parameters to use this handler.

Tags: Amazon AWS, Amazon PHP API, Learm PHP, PHP Classes