Using [19888] you can authenticate in Google site, just by following these steps:
1. You need to create a "Google client application" in Google site and obtain Client Id and Client Secret for that application.
Go to the following link: https://code.google.com/apis/console
2. There go to API Access section; first, click on the Credential section, and select "OAuth Client id":
Select "Application Type" = Web Application
Finally, you need to change the Redirect URIs. There you may specify the complete URI of your application, including the /oauth/gam/signin, as the figure shows:
In all cases - Java and NET-, you need to specify the complete URI of the application including the virtual directory followed by /oauth/gam/signin
Define a new Authentication Type = Google using the GAM - Web Backoffice.
Enter Cliend Id and Client Secret obtained in Google site.
About the Local Site URL configuration in GAM backend.
You just need to enter the domain of the server running the application.
It isn't necessary to enter the complete site URL, but in case you enter it, do not include the "/servlet" in java.
In the case of Web Applications, the GamExampleLogin object (which is part of the GAM example library) includes automatically a button by which the user can login to Google.
This button is included dynamically, as the Google Authentication Type is detected to be defined in the GAM Repository.
The following code is associated to the "Google" Button:
Event &ButtonGoogle.Click
GAMRepository.LoginGoogle()
EndEvent
The following code is used for that purpose:
Event 'Google'
Actions.LoginExternal("google", &User, &Password)
EndEvent
GAM - Facebook Authentication Type
GAM - Twitter Authentication Type
Additional Scope Property for GAM Google / Facebook Authentication Types