If you are using parse.com for your Angularjs based web app, and have Facebook as your login, you might find this useful.
I was building a quick web app and wanted people to login using Facebook. Initially, I used the standard Facebook login button fb:login, but I couldn't get the callbacks to work correctly.
In the end, I just created a custom login button and called a function on ng-click that wrapped Parse.FacebookUtils.logIn.
Hopefully this will save somebody a bit of time.