The Zend Developer Zone has a new post from Vikram Vaswani about accepting credit card payments through Authorize.net in the OXID eShop CE (e-commerce platform).

Now, if you're planning to start an online store, it should be pretty clear that accepting electronic payments isn't an option - it's a necessity for you to compete effectively. And that's where this article comes in. Over the next couple of pages, I'll show you how to begin accepting credit card payments for your products using the open source OXID shopping cart and the Authorize.Net payment gateway...with, of course, a little bit of PHP to make things interesting!

The glue between the OXID install and Authorize.net is created with the PEAR HTTP_Request2 package. This combined with a little extra PHP code can be installed and used as a component directly inside the application. He gives full code and screenshots to help you get it up and running on your install.

Shaun Oleson has posted his method (a chunk of code to do it) to connect to the Authorize.NET servers and make a request:

So I've had quite a bit of experience with authorize.NET and PHP and I've found it's difficult to find resources that provide textual examples for integrating the payment processor. I've put together a generic tutorial from documentation that is public. Of course, you will have to specify your Transaction ID and API Login ID. So here you are. If you need assistance or have any questions, feel free to leave a comment.

His example is a large get_auth() function that takes in the credit card information (including billing address) and makes a cURL connection to their servers for the request.

On the GoodPHPTutorials.com website there's a new tutorial showing how to get the Authorize.net API to talk back and forth between it and your application.

I have taken the time to abstract the AIM API into my own class that not only simplifies the code we will need to work with that API but also makes it modular and easy to port from application to application. To begin you will need to download the AuthnetAIM class. You can find it here.

He walks you through the setup and configuration of the library and includes a few examples of how to make both simple and more complex transactions through it.