Omniauth Example

familysearch.rb

require 'omniauth-oauth2'
require 'faraday'

module OmniAuth
  module Strategies
    class FamilySearch < OmniAuth::Strategies::OAuth2
      option :client_options, {
        :site => 'https://ident.familysearch.org',
        :authorize_url => '/cis-web/oauth2/v3/authorization',
        :token_url => '/cis-web/oauth2/v3/token'
      }
      option :api_site, "https://familysearch.org" 

      def request_phase
        super
      end

      def authorize_params
        super
      end

      uid { user_info['id'] }

      info do
        {
          :name => user_name,
          :email => user_email
        }
      end

      extra do
        { :raw_info => raw_info }
      end

      def raw_info
        @raw_info ||= get_user_info
      end
      
      def callback_url
        full_host + script_name + callback_path
      end

      def user_info
        @user_info ||= raw_info['users'] ? raw_info['users'].first : {}
      end

      def user_name
        user_info['contactName']
      end

      def user_email
        user_info['email']
      end
      
      protected
      
      def get_user_info
        conn = Faraday.new(:url => options.api_site)
        
        response = conn.get do |req|
          req.url '/platform/users/current'
          req.headers['Accept'] = 'application/x-fs-v1+json'
          req.headers['Authorization'] = "Bearer #{access_token.token}" 
        end
        
        return JSON.parse response.body
      end

    end
  end
end

OmniAuth.config.add_camelization 'familysearch', 'FamilySearch'

Gemfile

# frozen_string_literal: true
source "https://rubygems.org"

# gem "rails"

gem 'sinatra', '~> 1.4', '>= 1.4.7'
gem 'omniauth-familysearch'

sample-app.rb

# myapp.rb
require 'sinatra'
require 'omniauth'
require 'omniauth-familysearch'

use Rack::Session::Cookie
use OmniAuth::Builder do
  provider :familysearch, 'a0T3000000BfM3mEAF', '',
    :client_options => { :site => 'https://identbeta.familysearch.org' },
    :api_site => "https://beta.familysearch.org"
end

get '/' do
  '<a href="/auth/familysearch">Login</a>'
end

get '/auth/:name/callback' do
  auth = request.env['omniauth.auth']
  "#{auth.uid}, #{auth.info.email} #{auth.info.name} #{auth.credentials.token}"
  
  # do whatever you want with the information!
end