OmniAuth ADP OAuth2 Strategy

Strategy to authenticate with ADP via OpenID CConnect in OmniAuth.

Add to your Gemfile:

gem 'omniauth-adp-oauth2'

Then bundle install.

Here's an example for adding the middleware to a Rails app in config/initializers/omniauth.rb:

Rails.application.config.middleware.use OmniAuth::Builder do
  provider :adp_oauth2, ENV["ADP_CONSUMER_CLIENT_ID"], ENV["ADP_CONSUMER_CLIENT_SECRET"]
end

First define your application id and secret in config/initializers/devise.rb.

config.omniauth :adp_oauth2, "ADP_CONSUMER_CLIENT_ID", "ADP_CONSUMER_CLIENT_SECRET", { }

Then add the following to 'config/routes.rb' so the callback routes are defined.

devise_for :users, :controllers => { :omniauth_callbacks => "users/omniauth_callbacks" }

Make sure your model is omniauthable. Generally this is "/app/models/user.rb"

devise :omniauthable, :omniauth_providers => [:adp_oauth2]

Then make sure your callbacks controller is setup.

class Users::OmniauthCallbacksController < Devise::OmniauthCallbacksController
  def adp_oauth2
      # You need to implement the method below in your model (e.g. app/models/user.rb)
      @user = User.from_omniauth(request.env["omniauth.auth"])

      if @user.persisted?
        flash[:notice] = I18n.t "devise.omniauth_callbacks.success", :kind => "ADP"
        sign_in_and_redirect @user, :event => :authentication
      else
        session["devise.adp_data"] = request.env["omniauth.auth"]
        redirect_to new_user_registration_url
      end
  end
end

and bind to or create the user

def self.from_omniauth(access_token)
    data = access_token.info
    user = User.where(:email => data["email"]).first

    # Uncomment the section below if you want users to be created if they don't exist
    # unless user
    #     user = User.create(name: data["name"],
    #        email: data["email"],
    #        password: Devise.friendly_token[0,20]
    #     )
    # end
    user
end

For your views you can login using:

<%= link_to "Sign in with ADP", user_adp_oauth2_omniauth_authorize_path %>

<%# Devise prior 4.1.0: %>
<%= link_to "Sign in with ADP", user_omniauth_authorize_path(:adp_oauth2) %>

An overview is available at https://github.com/plataformatec/devise/wiki/OmniAuth:-Overview

Here's an example of an authentication hash available in the callback by accessing request.env["omniauth.auth"]:

• omniauth-google-oauth2

Copyright (c) 2016 by Puru Dahal

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