Customizing Paypal Express's Review Page using ActiveMerchant

Question

I am using ActiveMerchant to give my rails app access to Paypal\'s Express Checkout. I would like to include the Order Details on the Review Page as described here: https://cms.

Answer 1

You can see the available parameters in this table (only the middle column applies as activemerchant is using the SOAP API):

https://cms.paypal.com/us/cgi-bin/?cmd=_render-content&content_ID=developer/e_howto_api_ECCustomizing#id086NA300I5Z__id086NAC0J0PN

To best understand how activemerchant does it is probably to look directly into the implementation. You can see the relevant parameters getting inserted in the SOAP XML request (currently) starting at line 98 where the OrderTotal gets inserted:

https://github.com/Shopify/active_merchant/blob/master/lib/active_merchant/billing/gateways/paypal_express.rb#L98

Notice how the parameters are fetched from the options hash so you can see the correct symbol to pass for each one here.

In your case as you listed the following parameters, you would do it like this:

def paypal
  options = { 
    :name => "Tickets", 
    :quantity => @payment.quantity, 
    :description => "Tickets for #{@payment.event_name}",
    :amount => @payment.unit_price
    :ip => request.remote_ip,
    :return_url => url_for(:action=>:confirm, :id=>@payment.id, :only_path=>false),
    :cancel_return_url => url_for(:action=>:show, :id=>@payment.id, :only_path=>false)
  }

  # the actual code that gets used
  setup_response = gateway.setup_purchase(@payment.amount, options)
  redirect_to gateway.redirect_url_for(setup_response.token)
end

Note though: The name, quantity and amount fields are currently not support in activemerchant. You would have to fork the repository and insert these yourself and use your copy of the project. It's really very straightforward when you look at the code and see how it is done with the other ones.

For example to add the order name, item quantity and item unit price you would put these lines after the OrderDescription gets inserted:

  xml.tag! 'n2:Name', options[:name]
  xml.tag! 'n2:Amount', options[:amount]
  xml.tag! 'n2:Quantity', options[:quantity]

Hope that helps!

UPDATE:

Okay I think according to the XML Schema for the SOAP API it looks like you have to specify it like this in activemerchant:

xml.tag! 'n2:PaymentDetails' do
  items = options[:items] || []
  items.each do |item|
    xml.tag! 'n2:PaymentDetailsItem' do
      xml.tag! 'n2:Name', item[:name]
      xml.tag! 'n2:Description', item[:desc]
      xml.tag! 'n2:Amount', item[:amount]
      xml.tag! 'n2:Quantity', item[:quantity]
    end
  end
end

And you would pass all your items in your Rails app like this:

options = {
  :items => [
    { 
      :name => "Tickets", 
      :quantity => @payment.quantity, 
      :description => "Tickets for #{@payment.event_name}",
      :amount => @payment.unit_price
    },
    { 
      :name => "Other product", 
      :quantity => @other_payment.quantity, 
      :description => "Something else for #{@other_payment.event_name}",
      :amount => @other_payment.unit_price
    }
  ]
  :ip => request.remote_ip,
  :return_url => url_for(:action=>:confirm, :id=>@payment.id, :only_path=>false),
  :cancel_return_url => url_for(:action=>:show, :id=>@payment.id, :only_path=>false) 
}

Hope that works better, good luck!