devise_paypal

devise_paypal is Devise extension that allows you to authenticate users using the the Paypal Permissions API or the Paypal Authentication API through Devise.

Add devise_paypal to your Gemfile and make sure your using Devise from the git repository or at least version: "1.2.rc"

gem "devise", :git => "git://github.com/plataformatec/devise.git" # "1.2.rc"
gem "devise_paypal" #, :git => "git://github.com/dwilkie/devise_paypal.git" # for the latest and greatest

Ensure your bundle is installed and run the generator bundle rails g devise_paypal:install

As the generator instructs, you need to also add paypal-ipn to your gemfile then run its generator

gem 'paypal-ipn', :require => 'paypal' #, :git => "git://github.com/dwilkie/paypal.git" # for the latest and greatest

bundle
rails g paypal:initializer

This will create a configuration file where you can put your paypal api credentials.

Note: to enable the Paypal Permissions API you must file a ticket here. See this page for further details.

Using the devise method, add :paypal_authable and/or :paypal_permissions_authable to your model.

class User < ActiveRecord::Base
  devise paypal_authable, :paypal_permissions_authable
end

If you have chosen a model named User and devise_for :users is already added to your config/routes.rb, devise_paypal will create the following url methods:

new_user_paypal_authable
new_user_paypal_permissions_authable

Then you only need to add them to your layouts in order to provide Paypal authentication:

<%= link_to "Sign in with Paypal Authable", new_user_paypal_authable_path %>
<%= link_to "Sign in with Paypal Permissions Authable", new_user_paypal_permissions_authable_path %>

By clicking on these links, the user will be redirected to Paypal. Then after entering their credentials, they'll be redirected back to your application.

Implement a class method in your model called find_for_paypal_auth which accepts a single params hash argument. The params hash contains the information returned from Paypal in the following format:

:email => "johnny@example.com",
:first_name => "Johnny",
:last_name => "Walker",
:permissions => {
  :mass_pay => true
}

The method should return a single record which will be used to sign in the user. A simple implementation may look like this:

class User < ActiveRecord::Base
  def self.find_for_paypal_auth(params)
    if params
      user = self.find_or_initialize_by_email(params[:email])
      if user.new_record?
        stubbed_password = Devise.friendly_token[0..password_length.max-1]
        user.password = stubbed_password
        user.password_confirmation = stubbed_password
        user.save
      end
    else
      user = self.new
    end
    user
  end
end

See user.rb in the sample rails app for more details.

Say you want to request permission to access a Paypal API on behalf of a user. You can do this by overriding the devise_for call in your routes.rb file.

# routes.rb
devise_for :users, :controllers => {
  :paypal_permissions_authable => "paypal_registrations"
}

Then creating your own controller inheriting from: Devise::PaypalPermisssionsAuthableController

# app/controllers/paypal_registrations_controller.rb
class PaypalRegistrationsController < Devise::PaypalPermissionsAuthableController
  def new
    @permissions = {:mass_pay => true}
    super
  end
end

In this case be sure to remember to modify the keys for your locale file: # config/locales/devise_paypal.en.yml en: devise: paypal_registrations: success: "Successfully authorized from paypal account."

By default, if a non-persisted record is returned by your model callback method, the user will be rendered the new registrations page from devise :registrations

To change this behavior simply override render_for_paypal in your controller

# app/controllers/paypal_registrations_controller.rb
class PaypalRegistrationsController < Devise::PaypalPermissionsAuthableController
  private

  def render_for_paypal
    render "welcome#index"
  end
end

For more details check out the source

The gem comes with sample rails app so you can try things out in your browser. To start it:

git clone git://github.com/dwilkie/devise_paypal.git
cd devise_paypal/test/rails_app
bundle
rake db:migrate
rails s

Then go to http://localhost:3000. Remember to replace the values in config/initializers/paypal.rb with your Paypal API credentials.

Copyright (c) 2010 David Wilkie, released under the MIT license