Facebook Apps: Additional permissions

It’s as simple as adding the new permission to a new fb:login-button:

<fb:login-button scope="publish_stream">
  Let me write on your wall!
</fb:login-button>

So for example you have the above hidden in a DIV and if the user tick a checkbox you show the DIV and prompt the new permission!

A good live example of this is on the Facebook Test Console:

1. Click login to “add” the application
2. Then click on examples
3. Under fb.api choose does-like

Now you can see that even after being *connected to the application (test console app), you can actually have another login button to prompt the user!

EDIT:
To check if the user has granted your application a permission, just use this FQL:

SELECT read_stream,offline_access FROM permissions WHERE uid=me()

This would return something like:

[
  {
    "read_stream": 1,
    "offline_access": 0
  }
]

To test it, just use the test console posted early.

EDIT 2:
To construct the link yourself without XFBML or Javascript, you just need to add the scope parameter with the additional perms (reference):

https://www.facebook.com/dialog/oauth?
     client_id=YOUR_APP_ID&redirect_uri=YOUR_URL&scope=publish_stream

Or if your are using the PHP-SDK:

$loginUrl = $facebook->getLoginUrl(array(
    "scope" => "publish_stream"
));