Ruby on Rails PayPal IPN Code Example

I thought I’d share the skeleton of some code I had to write for PayPal’s backend IPN API.

# process the PayPal <span class="caps">IPN POST</span> def paypal_ipn if @request.method == :post # use the POSTed information to create a call back <span class="caps">URL</span> to PayPal @query = ‘cmd=_notify-validate’ @request.params.each_pair {|key, value| @query = @query + ’&’ + key + ’=’ + value.first if key != ‘register/pay_pal_ipn.html/pay_pal_ipn’ }</p> <ol> <li><span class="caps">POST</span> this data http = Net::HTTP.start(PAYPAL_URL, 80) response = http.post(’/cgi-bin/webscr’, @query) http.finish</li> </ol> <h1>PayPal values</h1> <pre><code> item_name = @params[:item_name] item_number = @params[:item_number] payment_status = @params[:payment_status] payment_amount = @params[:mc_gross] payment_currency = @params[:mc_currency] txn_id = @params[:txn_id] receiver_email = @params[:receiver_email] payer_email = @params[:payer_email]<br/><br/> if response if response.body.chomp 'VERIFIED' # check the payment status if payment_status &#8216;Completed&#8217; # check to see if the txn_id already exists # your logic here end end else # <span class="caps">GET</span> request, wtf @text = &#8216;I do not speak <span class="caps">GET</span>&#8217; end </code></pre> <p> rescue Net::HTTPError @text = ‘HTTP error’ end

This method exists inside of a controller class. I’m certainly not saying that this is the best or most elegant way to handle this, just that I couldn’t find any examples to rip-off myself. :)

Let me know if you have any suggestions. WARNING: this code does not communicate with PayPal’s servers over SSL.