Is it possible to display Facebook Like Button only if user is logged to Facebook?

Question

If user is not logged to facebook then clicking on Like Button opens a popup window prompting for user to login. I don't want that popup to display - hence the best would be to not show Like button for visitors that are not logged to Facebook.

Is it possible?

Answer 1

Yes and no. It is possible when your facebook application is not shown in a tab because in a tab facebook runs no javascript and no user information is passed until the user clicked somewhere.

If you are writing a "real" facebook app, you could try the following code, I do this in PHP like this:

// Get user id
public function getUserId()
{
    $user_id = 0;
    try
    {
        $user_id = $this->facebook->api_client->users_getLoggedInUser();
    }
    catch(Exception $e)
    {
        $user_id = 0;
    }   

    return $user_id;
}

If this code returns "0", a guest is viewing the application.