Hi Ashutosh,

First you should not extend an existing provider, but instead create your own one! Because, if you upgrade your module, you will loose your changes.

Basic steps to create a gateway provider:

1. Copy the files from the folder \DesktopModules\Store\Cart\Providers\GatewayProviders\PayPalProvider
2. Create a new folder (YourOwnProvider) inside \DesktopModules\Store\Cart\Providers\GatewayProviders\
3. Paste the files inside your new folder
4. Rename all files with your own provider name (eg: PayPalAdmin ascx > YourOwnNameAdmin)
5. Rename all class names and namespaces with 'YourOwnName'
6. Add the new project to the Store solution
7. Create a new folder (YourOwnProvider) inside \DesktopModules\Store\Providers\GatewayProviders\
8. Correct folder names in the post build event

Your provider should have a parameter the notification url. In the payPal provider you have a parameter named NotifyURL transmited in the form field 'notify_url'. Look at the code in the method ConfirmOrder in the class PayPalPayment. A TransactionDetail object is created to store the url parameters (ReturnURL, CancelURL and NotifyURL) and this object is passed as parameter to the PayPalGatewayProvider class (provider.ProcessTransaction(CheckoutControl.BillingAddress, order, transaction)). The provider class build the form to transmit to the PayPal server.

In the ConfirmOrder method the NotifyURL is build to call an aspx page (PayPalIPN.aspx) like this: transaction.NotifyURL = urlAuthority + TemplateSourceDirectory + "/PayPalIPN.aspx?language=" + language. Your should have a similar page (YourOwnNameIPN.aspx) to get the response from your gateway provider and update the order status.

Gilles