PHP Facebook saving user creds?

is it possible to save the user details (the Signed request开发者_高级运维 that facebook sends after validation) to a database for future use?

NOTE: i DO NOT mean adding a random signed request, i merely mean the signed request that facebook sends AFTER user has successfully added your app + signed into facebook.

Yes. You can save it. Once it's on your server, you can do whatever you like with it.

Should you? I think not. That data is supposed to only be available to you while the user is using your app.

One thing to note: if you want to make calls to the Open Graph API on behalf of the user, any tokens you use will expire when they log out (unless you have requested the "offline access" permission).

After the user has authorized your app, you should continue to get a "user" object in your signed_request that includes their FB user id.