Accessing the Google DFP API with a OmniAuth refresh token

Question

I am working on a rails app where I need to access users Google Double Click for Publisher Data. I am using the 'google-dfp-api' gem. I have set up OmniAuth for users to authenticate their DFP accounts and am storing the refresh token per the google documentation (https://developers.google.com/doubleclick-publishers/docs/authentication). I can not figure out how to use the refresh token to access the DFP api.

I am attempting to make the connection as shown below:

dfp = DfpApi::Api.new({
      :authentication => {
        :method => 'OAuth2',
        :oauth2_client_id => GOOGLE_CLIENT_ID,
        :oauth2_client_secret => GOOGLE_CLIENT_SECRET,
        :user_agent => USER_AGENT,
        :application_name => APP_NAME,
        :oauth2_token => {
          :refresh_token => GOOGLE_DFP_REFRESH_TOKEN
        }
      },
      :service => {
        :environment => 'PRODUCTION'
      }
    })

AnyTime I attempt to make a query after this I get the following error:

DfpApi::V201411::UserService::ApiException: [AuthenticationError.AUTHENTICATION_FAILED @ ]

Answer 1

You do not use the refresh token to access the api, use your access_token. I am refreshing the access_token before I make a call.

Refresh your token:

 def refresh_access_token
   refresh_token = self.refresh_token
   google_refresh_url = "https://accounts.google.com/o/oauth2/token"
   response = RestClient.post google_refresh_url, :grant_type => 'refresh_token', :refresh_token => refresh_token, :client_id => ENV['GOOGLE_CLIENT_ID'], :client_secret => ENV['GOOGLE_CLIENT_SECRET']
   response_hashed = JSON.parse(response)
   new_access_token = response_hashed['access_token']
   self.save_new_access_token(new_access_token)
 end

Then the OAuth DFP API hash should look as below:

@api = DfpApi::Api.new({
  :authentication => {
    :method => 'OAuth2',
    :oauth2_client_id => ENV['GOOGLE_CLIENT_ID'],
    :oauth2_client_secret => ENV['GOOGLE_CLIENT_SECRET'],
    :application_name => ENV['GOOGLE_APP_NAME'],
    :client_customer_id => google_dfp_credential.google_client_customer_id,
    :network_code => google_dfp_credential.network_code,
    :user_agent => ENV['GOOGLE_DFP_USER_AGENT'],
    :oauth2_token => {
      :access_token => google_dfp_credential.access_token,
     },
   },
   :service => {
     :environment => 'PRODUCTION'
    }
  })

The user_agent is a unique string to your app, that should be the same every time you access the api. See the link below for more info on that:

http://googleadsdeveloper.blogspot.com/2013/11/please-set-user-agent-or-application.html

You will also need to get the network_code from the the dfp account you are accessing by logging into the dfp account manually. To my knowledge this is not returned with OAuth authentication. See step 2 in the link below for more info on how to get the network_code:

https://developers.google.com/doubleclick-publishers/docs/start