Amazon API Access with PHP and XML: A PHP XML class to access Amazon API they released

Hello,

Now everybody heard of Amazon.com. What not everybody knows that Amazon released an API to access its huge catalogs. What this basically means is that each developer can access the information from Amazon following some simple protocols and every site owner can enhance his own website with content and features from Amazon.

The Amazon API comes as a simple Webservice. Here are the first Web services that they have exposed:
- Product Display : The ability to search for and retrieve product information from the Amazon.com catalog.
- Shopping Cart : The ability to add Amazon.com products to shopping carts, wish lists, and registries from third party locations.

No matter of your intentions, you will first need to register and obtain a valid developer token. You can get your token here at this address: http://www.amazon.com/webservices

The current listed implementation of Amazon webservices uses Keyword searches. It has basically the same results as searching the books catalog online. As any developer/webmaster can see in the "Amazon.com Web Services Developers Kit v 1.0" document, a lot of other Amazon features are exposed. This would imply extending the base structure I present here.

There are multiple approaches from a developer's point of view. The simplest one deals with SOAP and web services classes already implemented in PHP. You could also extend the PEAR's XMLParser object to parse Amazon results. The reason I did not choose these directions is because they require additional extensions installed with PHP. What I currently use is the XML parsing package that comes embedded in PHP, so it is slightly more general.

What basically happens in this implementation is that the search word entered by the used is embedded into a XML url that is then retrieved from Amazon.com. Then PHP builds a nice display for the information received.

I should let the code talk for itself. Here is the main controller, with a small search form for Amazon:

http://www.php9.com/php/source/amazon.phps

As you see, the actual code is very small. Then here is the class used in the controller to parse the XML returned by Amazon.

http://www.php9.com/php/source/amazon_class.phps

Then the configuration file. I need to remember you that you need to change the DEVELOPER_TOKEN constant with the one you will obtain from Amazon. The current license key belongs to me. You also need to change the ASSOCIATE_ID constant with a one from Amazon. You also need to do the same change in the file php9-data-to-html.xsl, the engine for the XSLT transformation.The current constant set belongs to me also.

http://www.php9.com/php/source/amazon_config.phps

And here is the layout template used to build the output from the XML document retrieved from Amazon. It is parsed every time a book record is retrieved, so the output rendering is the fastest possible.

http://www.php9.com/php/source/amazon_layout.phps

And here is the XSLT document used to build the HTML product page document from the XML document retrieved from Amazon.

http://www.php9.com/php9-data-to-html.xsl

Here you have the full package zipped.

http://www.php9.com/php/source/amazon.zip

And of course a demo: http://www.php9.com/amazon.php

As the project improved a lot during the latest months, I created a freshmeat project here:
http://freshmeat.net/projects/amazon_webservice_api/

and a class collection in the extensive package provided by Manuel Lemos:
http://www.phpclasses.org/browse.html/package/642.html

Feel free to use it and improve. I am open to suggestions.

The class has been updated to use Amazon Webservices Version 2 (search order, number of results).