Simple LinkedIn OAuth2 authentication

linkedin_oauth2_sample.rb

  require 'oauth2'
  require 'net/http'
  require 'uri'
  
  API_KEY = 'XXXXXXXXX' #Your app's API key
  API_SECRET = 'XXXXXXXXXXXXX' #Your app's API secret
  REDIRECT_URI = 'http://localhost:3000/accept' #Redirect users after authentication to this path
  
  #Instantiate your OAuth2 client object
  def client
    OAuth2::Client.new(
       API_KEY, 
       API_SECRET, 
       :authorize_url => "/uas/oauth2/authorization?response_type=code", #LinkedIn's authorization path
       :token_url => "/uas/oauth2/accessToken", #LinkedIn's access token path
       :site => "https://www.linkedin.com"
     )
  end
  
  def index
    authorize
  end

  def authorize
    #Redirect your user in order to authenticate
    redirect_to client.auth_code.authorize_url(:scope => 'r_fullprofile r_emailaddress r_network', 
                                               :state => 'STATE', 
                                               :redirect_uri => REDIRECT_URI)
  end

  # This method will handle the callback once the user authorizes your application
  def accept
    #Fetch the 'code' query parameter from the callback
    code = params[:code] 
    
    #Get token object, passing in the authorization code from the previous step 
    token = client.auth_code.get_token(code, :redirect_uri => REDIRECT_URI)
    
    #Use token object to create access token for user 
    #(this is required so that you provide the correct param name for the access token)
    access_token = OAuth2::AccessToken.new(client, token.token, {
      :mode => :query,
      :param_name => "oauth2_access_token",
      })
    
    #Use the access token to make an authenticated API call
    response = access_token.get('https://www.linkedin.com/v1/people/~')
    
    #Print body of response to command line window
    puts response.body
  end