This library is here to aid with integrating Paypal payments into ruby on rails applications or similar. To set this up you will need to log into your paypal business account and tell paypal where to send the IPN ( Instant payment notifications ).

• Preferred method of installation is using rubygems. gem install JonathanTron-paypal
• Alternatively you can get the source code at http://github.com/JonathanTron/paypal

• Ruby 1.8.2 (may work with previous versions) With OpenSSL support compiled in.
• Valid paypal business account.
• (optional) The money library from http://dist.leetsoft.com/api/money

1. sudo gem install JonathanTron-paypal --source=http://gems.github.com

2. Require the library

    require "paypal"
   

2.1. If you're using Rails add :

    require "paypal/rails"

3. Create a paypal_ipn ( or similar ) action like the one in the "Example action" appendix.

Within the new payment controller you can now create pages from which users can be sent to paypal. You always have to sent users to paypal using a HTTP Post so a standard link won't work (well OK but you need some javascript for that). The +Paypal::Helper+ namespace has some examples of how such a forward page may look.

Under https://developer.paypal.com/ you can signup for a paypal developer account. This allows you to set up "sandboxed" accounts which work and act like real accounts with the difference that no money is exchanged. Its a good idea to sign up for a sandbox account to use while the application is running in development mode.

class BackendController < ApplicationController

  # Simplification, please write better code then this...
  def paypal_ipn
   notify # Paypal::Notification.new(request.raw_post)

   if notify.acknowledge
     order # Order.find(notify.item_id)
     order.success # (notify.complete? and order.total # notify.amount) ? 'success' : 'failure'
     order.save
   end

   render :nothing #> true
  end
end

<%# paypal_form_tag %> <%# paypal_setup "Item 500", Money.us_dollar(50000), "bob@bigbusiness.com", :notify_url #> url_for(:only_path #> false, :action #> 'paypal_ipn') %>

 Please press here to pay $500US using paypal. <br/>
 <%# submit_tag "Go to paypal >>" %>

or, with the same results, the block version:

<% paypal_form_tag do %> <%# paypal_setup "Item 500", Money.us_dollar(50000), "bob@bigbusiness.com", :notify_url #> url_for(:only_path #> false, :action #> 'paypal_ipn') %>

 Please press here to pay $500US using paypal. <br/>
 <%# submit_tag "Go to paypal >>" %>

<% end %>

Paypal supports encrypted form data to prevent tampering by third parties. You must have a verified paypal account to use this functionality.

1. Create a private key for yourself

   openssl genrsa -out business_key.pem 1024

2. Create a public certificate to share with Paypal

   openssl req -new -key business_key.pem -x509 -days 3650 -out business_cert.pem

3. Upload the public certificate to Paypal (under Profile -> Encrypted Payment Settings -> Your Public Certificates -> Add), and note the "Cert ID" that Paypal shows for the certificate.

4. Update your controller to include the details for your key and certificate.

   @business_key # File::read("business_key.pem") @business_cert # File::read("business_cert.pem") @business_certid # "certid from paypal"

5. Update your views to populate the :business_key, :business_cert and :business_certid options in 'paypal_setup' - the rest of the signature is the same.

6. When you're ready to go live, download the production Paypal certificate and override the default certificate.

   Paypal::Notification.paypal_cert # File::read("paypal_cert.pem")

7. Finally, add the following line to your environment.rb or inside an initializer:

   Paypal::Notification.ipn_url # "https://www.paypal.com/cgi-bin/webscr"

uninitalized constant Paypal - Make sure your ruby has openssl support