Chapter 1

Introduction

After several years experience with two Joomla components that include online payment processing, we realised that building the payment processing directly into a Joomla application was a mistake. The payment processing code is complex, and is time-consuming to develop, test, and maintain. When users asked, "how easy is it to add support for a new payment gateway?", our response was: "Nearly impossible, and prohibitively expensive". We needed a separate component to handle payments and payment gateways.

The solution is Payage, a Joomla Component that manages online payments with multiple payment gateways and multiple Joomla components. Payage only deals with payments. It is not a shopping cart or a booking system. On its own, Payage does nothing useful. But when used as an isolation layer between an application and its payment processing, it makes the application code simpler and cleaner, and makes it much easier to add new payment gateways.

Payage has many advantages for both developers and site administrators.

• Gateway processing and application processing are completely separated. As a result, both are greatly simplified.
• Payage has a well-documented Application Programming Interface. Developers can build sales applications without knowing anything about payment gateways.
• Adding new payment gateways is well documented, relatively straightforward, and has no impact on applications.
• Administrators have a single method of configuring payment gateways, and can see payments for multiple applications all in one place.
• The payment documentation is all in one place and is not duplicated for each application.
• Application developers save a great deal of time in development, testing, and documentation.
• Troubleshooting is easier because you can work on payments and the application separately.

This document is for programmers who want to:

• Use Payage to enable payments in their own Joomla extension and/or
• Implement a new payment gateway for Payage

This is a detailed technical document for programmers with an advanced knowledge of Joomla and PHP. Non-technical users and administrators should refer to the Payage User Guide.

We assume that the reader is already familiar with the Payage User Guide.