Ruby-PayPal

Set it up in your rails application

In your gemfile:

gem "ruby-paypal", :git => "git://github.com/Reprazent/ruby-paypal.git"

To use Ruby-PayPal

It's critical that you understand how PayPal works and how the PayPal NVP API works. You should be relatively well-versed in the NVP API Developer Guide and Reference (https://www.paypal.com/en_US/ebook/PP_NVPAPI_DeveloperGuide/index.html). You should also visit and register yourself with the PayPal Developer Network and get a Sandbox account with in the PayPal Development Central (https://developer.paypal.com/).

Note that this library only supports the API signature method of securing the API credentials.

Using the Ruby-PayPal library is relatively simple:

Initialize a paypal object

paypal = Paypal.new(<username>,<password>,<signature>,<url>)

The url is the paypal API to use: sandbox for development, normal for production:

        development:
          username: username
          password: pass
          signature: sig
          url: sandbox
          action: https://www.sandbox.paypal.com/cgi-bin/webscr
        test:
          username: username
          password: pass
          signature: sig
          url: sandbox
          action: https://www.sandbox.paypal.com/cgi-bin/webscr
        staging:
          username: username
          password: pass
          signature: sig
          url: sandbox
          action: https://www.sandbox.paypal.com/cgi-bin/webscr
        production:
          username: "username"
          password: "password"
          signature: "signature"
          url: production
          action: https://wwwpaypal.com/cgi-bin/webscr

For the Direct Payment using credit card payment, you need to use the

DoDirectPayment APIs:

username = <PayPal API username>
password = <PayPal API password>
signature = <PayPal API signature>

ipaddress = '192.168.1.1' # can be any IP address
amount = '100.00' # amount paid
card_type = 'VISA' # can be Visa, Mastercard, Amex etc
card_no = '4512345678901234' # credit card number
exp_date = '022010' # expiry date of the credit card
first_name = 'Sau Sheong'
last_name = 'Chang'

paypal = Paypal.new(username, password, signature)
response = paypal.do_direct_payment_sale(ipaddress, amount, card_type,
		   card_no, exp_date, first_name, last_name)
if response.ack == 'Success' then
  # do your thing
end

The above code is for a final sale only.

Note that the credit card number is checked against a modulo-10 algorithm (Luhn check) as well as a simple credit card type check. For more information please refer to http://en.wikipedia.org/wiki/Luhn_algorithm and http://en.wikipedia.org/wiki/Credit_card_number

For the Express Checkout using the customer's PayPal account for payment, you will need to use the ExpressCheckout APIs (Updated!)

You can get a paypal token trough paypal.do_set_express_checkout(return_url, cancel_url, products, currency="USD", other_params={})

The products parameter is an array of hashes like this:

{:price => 1.99, :name => "NAME", :quantity => 1, :description => "DESCRIPTION"}

Using the token returned you can build URL's that will allow the user to pay trough paypal, get the payment info from paypal like this:

paypal.do_get_express_checkout_details(token)

Using the info returned you can do the actual payment:

paypal.do_express_checkout_payment(token,'Sale', payer_id, amount)

The amount parameter needs to be the same as the one calculated from the products passed when getting the token.

Source

Originally by:

• Author: Chang Sau Sheong (mailto:sausheong.chang@gmail.com)
• Author: Philippe F. Monnet (mailto:pfmonnet@gmail.com)

The original source can be found on http://rubyforge.org/projects/ruby-paypal/