Facebook login implementation

Question

I have a website where I want to implement the facebook-login facility.. I went through the facebook developers pages, but they are kinda vague and unable to understnad completely.

My website is a php-mysql application, I already have a signing up process for new users in my website, but I want users to have an option of logging in with their facebook ID's and also, once they login, I want to store their ID's in my mysql database to identify them next time.

I have gone through similar topics in SO, but unable to crack it. If anybody could link me to a step-by-step clear guide to implement this on my website.

Answer 1

have a look at

http://developers.facebook.com/blog/post/503/

Answer 2

Just did a quick Google search on this and found the following blog post: link. Seems to cover setting up an FB login in php.

The post says that when you call $facebook->require_login(); it prompts the user to login using FB and then upon successful logging-in, returns you an FB id so you could write something like $fb_id = $facebook->require_login(); and then store $fb_id.

Here's the full hello world example - best to read through the blog post for a more complete tutorial:

<?php
/* include the PHP Facebook Client Library to help
  with the API calls and make life easy */
require_once('facebook/client/facebook.php');

/* initialize the facebook API with your application API Key
  and Secret */
$facebook = new Facebook(YOUR_API_KEY,YOUR_SECRET_CODE);

/* require the user to be logged into Facebook before
  using the application. If they are not logged in they
  will first be directed to a Facebook login page and then
  back to the application's page. require_login() returns
  the user's unique ID which we will store in fb_user */
$fb_user = $facebook->require_login();

/* now we will say:
  Hello USER_NAME! Welcome to my first application! */ 
?>

Hello <fb:name uid='<?php echo $fb_user; ?>' useyou='false' possessive='true' />! Welcome to my first application!

<?php

/* We'll also echo some information that will
  help us see what's going on with the Facebook API: */
echo "<pre>Debug:" . print_r($facebook,true) . "</pre>";

?>