How to: Check if User Has Certian Permission – Facebook API

There are two three ways to check if the user has granted your application a specific Permission:

Using the Graph API

Now that Facebook added the permissions connection to the user object, you can easily check the user’s permission:

$permissions = $facebook->api("/me/permissions");
if( array_key_exists('publish_stream', $permissions['data'][0]) ) {
	// Permission is granted!
	// Do the related task
	$post_id = $facebook->api('/me/feed', 'post', array('message'=>'Hello World!'));
} else {
	// We don't have the permission
	// Alert the user or ask for the permission!
	header( "Location: " . $facebook->getLoginUrl(array("scope" => "publish_stream")) );
}

Using the FQL permissions table

You can query the permissions table to check if a certain permission (or set of permissions) is granted:

SELECT read_stream FROM permissions WHERE uid=me()

We will give two examples of how to query this table in:

• PHP:

  $perms = $facebook->api(array(
  	"method"	=> "fql.query",
  	"query"		=> "SELECT read_stream,offline_access,publish_stream FROM permissions WHERE uid=me()"
  ));
  echo "<ul>";
  foreach($perms[0] as $k=>$v) {
  	echo "<li>";
  	if($v === "1") {
  		echo "<strong>$k</strong> permission is granted.";
  	} else {
  		echo "<strong>$k</strong> permission is not granted.";
  	}
  	echo "</li>";
  }
  

  Output:

  • read_stream permission is not granted.
  • offline_access permission is not granted.
  • publish_stream permission is granted.

• Javascript:

  FB.api({ method: 'fql.query', query: 'SELECT read_stream,offline_access,publish_stream FROM permissions WHERE uid=me()' }, function(resp) {
  	for(var key in resp[0]) {
  		if(resp[0][key] === "1")
  			console.log(key+' is granted')
  		else
  			console.log(key+' is not granted')
  	}
  });
  

Using the REST API users.hasAppPermission method

It is worth mentioning that the users.hasAppPermission is still working and can be called from the Facebook PHP-SDK like so:

$isGranted = $facebook->api(array(
	"method"    => "users.hasAppPermission",
	"ext_perm"   => "publish_stream",
	"uid"       => 579187142
));
if($isGranted === "1")
	echo "Permission granted!";

Please note that this call doesn’t require the uid parameter, if you have a valid user session.

Now we call the same function in Javascript:

FB.api({ method: 'users.hasAppPermission', ext_perm: 'publish_stream' }, function(resp) {
	if (resp === "1") {
		alert('Permission granted');
	} else {
		alert("Permission not granted");
	}
});