One-off and subscription payments for your Rails application.

Add Payola to your Gemfile:

gem 'payola'

Run the installer and install the migrations:

$ rails g payola:install
$ rake db:migrate

To start selling one-off products, just include Payola::Sellable. For example, if you have a Book model:

class Book < ActiveRecord::Base
  include Payola::Sellable
end

Each sellable model requires two attributes:

• permalink, a human-readable slug that is exposed in the URL
• name, a human-readable name exposed on product pages

When people buy your product, Payola records information in Payola::Sale records, and will record history if you have the paper_trail gem installed. It is highly recommended to install paper_trail.

To sell a product, send the user to /payola/buy/:product_class/:permalink. For our book example, if you have a Book with the permalink `mastering-modern-payments, you would send them to:

/payola/buy/book/mastering-modern-payments

You can provide short-cut paths in your application's routes like this:

get '/buy/mmp', to: 'payola/transactions#new', defaults: {
  product_class: 'book',
  permalink: 'mastering-modern-payments'
}

TODO

# config/initializers/payola.rb

Payola.configure do |payola|
  payola.subscribe 'payola.sale.finished' do |sale|
    SaleMailer.receipt(sale.guid).deliver
  end

  payola.subscribe 'payola.sale.failed' do |sale|
    SaleMailer.admin_failed(sale.guid).deliver
  end

  payola.subscribe 'payola.sale.refunded' do |sale|
    SaleMailer.admin_refunded(sale.guid).deliver
  end
end

Payola wraps the StripeEvent gem for event processing and adds a few special sale-related events. Each one of these events passes the related Sale instance instead of a Stripe::Event. They are sent in-process so you don't have to wait for Stripe to send the corresponding webhooks.

• payola.sale.finished, when a sale completes successfully
• payola.sale.failed, when a charge fails
• payola.sale.refunded, when a charge is refunded

You can subscribe to any webhook events you want as well. Payola will dedupe events as they come in. Make sure to set your webhook address in Stripe's management interface to:

https://www.example.com/payola/events

To subscribe to a webhook event:

Payola.configure do |payola|
  payola.subscribe 'charge.succeeded' do |event|
    sale = Sale.find_by(stripe_id: event.data.object.id)
    SaleMailer.admin_receipt(sale.guid)
  end
end

### Background Jobs

Payola will attempt to auto-detect the job queuing system you are using. It currently supports the following systems:

* Sidekiq

If you want to force Payola to use a specific supported system, just set `background_worker` to the appropriate symbol. For example:

```ruby
Payola.background_worker = :sidekiq

You can also set this to anything with a call method, for complete control over how Payola's jobs get queued. For example, you can run transactions in-process like this:

Payola.background_worker = lambda do |sale|
  sale.process!
end

Please see the LICENSE file for licensing details.

Pete Keen, @zrail, https://www.petekeen.net