Online Payment Solution for RoR Application: PayPal - IPN

... continued from PayPal Integration Basics

If you want to do some operations after getting payment confirmation i.e. Instant Payment Notification(IPN) which would sent by PayPal after every transaction (either completed or not), then you can follow next steps:

14. First of all you need to enable IPN in your paypal account. Login to merchant account -> Profile -> Instant Payment Notification Preferences -> Enter notification url and select radio button "Receive IPN messages" -> Save

Note: You cannot get IPN on your rails local server, as you cannot set local address of your application while enable IPN from your paypal account.

15. After getting IPN, you can make any operation according to your application's need. In my app, I am going to make operations on my new model after getting IPN. For this, generate a new model and migrate it to database:

$ rails generate model order product_id:integer quantity:integer amount:decimal status:string

$ rake db:migrate

16. Now time to make associations,

• In app/models/product.rb, add

has_many :orders

• In app/models/order.rb, add

belongs_to :product

17. Open config/route.rb, replace

resources :products

with

resources :products do

collection do

post 'notification'

end

end

18. Add new method in app/controllers/products_controller.rb, for handelling IPN

def notification

#handle for old deals.
if params[:item_number1] && !params[:item_number1].empty?

#paypal sends an IPN even when the transaction is voided.
if params[:payment_status] != 'Voided'

@product = Product.find(params[:item_number1].to_i) rescue nil @product.orders.build(:quantity => 1, :amount => params[:mc_gross_1], :status => params[:payment_status]).save unless @product.nil?

end

end
render :nothing => true

end

In app/views/products/index.html.erb,

replace

product.paypal_url(products_url)

with

product.paypal_url(products_url, notification_products_url)

and add a new line after

:return => return_url

in paypal_url method (in app/models/product.rb), for supporting notify_url:

:notify_url => notify_url

also change signature of this method to accept notify_url parameter, it will look like:

def paypal_url(return_url,notify_url)

Done with IPN implementation, you can cross check for your IPN:

Login to merchant account -> History -> IPN History

The fully implemented application is uploaded on heroku: PayPal Integration.
You can checkout application's code here.

Go Back to PayPal Basics
Must read about Security while Payments

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