Yehey! I am glad another payment gateway will go into OpenACS 4.x. Maybe initially doing it as a singleton is ok. But in the long run it must be a service that probably will make use of acs-service-contract. Not sure though if acs-service-contract since I have not got that deep yet.
The basic need is to create a service that would provide application as a means to process credit cards. It maybe ecommerce or some other app. Basically ecommerce maybe a sample of how to use this service. Much like CMS and ETP is an application that makes use of CR. This would make it faster for other developers to make ecommerce solution that will not use the ecommerce app since their needs may drastically be different. But this ecommerce service can be reused.
Its a lot better to break down the ecommerce stuff. I really dont know about OpenACS 4.x ecommerce but ecommerce from 3.x is really huge.
Based from 3.x we can break down the ecommerce thing to:
-products handling
-transaction auditing
-payment processing one of the option is credit card processing. Another option maybe a points system. This points system maybe developed by the developer since points systems are normally very custom.
-transaction administration. This is the revoke, fulfill, etc. But this may not be used in favor of the cash register of Cybercash.
Of course all of the above are move long term. I think for short term is to just get the ecommerce package to use another payment gateway. Then move the payment gateway to a service. Then break down ecommerce to more usable independent units.
