ProxyPay3 Eurobank Greek Bank Gateway (Redirection) For Yii Framework
But outlines the process and will help you work out the specifics of your implementation.You can apply it in any PHP MVC framework,(it can be adapted since there's little framework specific code).
To better understand this code you have to ask for documentation PDFs,sample PHP files and credentials for a demo account from the bank's IT support. After they send you these files,you will be asked to provide them with checkout,validation,ok,notok,and confirmation URLs as described in documentation. If you do tests as a developer using a demo account unfortunately you will NOT be able to verify a complete successful transaction and render a successful OK page using a demo credit card number. You will need a real credit card number for that.This is a restriction of the ProxyPay system,probably for security reasons. If you want to debug,you will have to ask for ProxyPay's server log from their IT helpdesk (via email) for EVERY transaction test you make. Super inconvenient,but unfortunately that's the way it is.