I want to download a video from facebook to the clients local drive. I saw a few browser plugins and Facebook apps that are able to that and I was wondering how it can be done using the GraphAPI or in any other way.
First, you get the Graph API object. If the object is public, it's simple, just get https://graph.facebook.com/10151651550011063. (Where the number is the object's ID, equal to the ?v=OBJECTID in the facebook video URL.)
If the object is not public, you need a valid access_token, and the Graph API url becomes something like https://graph.facebook.com/10151651550011063?access_token=DFSDSGSFDGFGDSblabla
Then, in the Graph API object, you'll find the video download link under source.