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When a social network is integrated with eXo Platform, the UI flow will be as follows:
The login page will have new buttons below:
When clicking the Facebook button for example, the OAuth authorization flow starts. The user will be redirected to the Facebook page and be asked for login if not yet. Facebook then asks the user if he allows eXo to access his profile data.
If the user accepts, he is logged into eXo and redirected to the homepage.