I have a website which hosts events, is registered as an FB App and supports FB Login. When users logged in with Facebook click the 'Like' button (standard Javascript Social Plugin), FB successfully scraps the event page (which has Open Graph tags including FB app ID) and posts to their feed, but the post is always set to the 'Only Me' privacy setting.
A workaround for this is to have the user change the privacy setting for the app in Privacy Settings -> Apps, but ideally I'd like them to select how to share it when they hit the 'Like' button. Is there a way to do that?
I've tried changing the Default Activity Privacy setting for my App, but it has no effect. I assume this is because that setting only applies to Likes issued by my App on the user's behalf, not those initiated by the user through the standard Javascript-generated 'Like' button.
I was able to solve this myself. Apparently when you use Facebook Login as well as the XFBML Like button, the Like button functions as if your Facebook App, rather than the user himself is performing the action. I found that by requesting the publish_actions permission when invoking FB.login, Facebook would prompt the user to set the privacy level for the app, the default being what is set for Default Activity Privacy. The privacy level selected there is applied when sharing through Like button. Users who do not use Facebook login do not have any issues. The privacy level of their Likes is determined by their normal privacy settings.