pass facebook connect session from php to javascript

I'm authenticating via PHP:

// the php facebook api downloaded at step 3
require_once("facebook-client/facebook.php");

// start facebook api with the codes defined in step 1.
$fb=new 开发者_StackOverflowFacebook( 'XXXXXXXXXXXXXXXXXXXX' , 'a3eaa49141ed38e230240e1b6368254a' );
$fb_user=$fb->get_loggedin_user();

var_dump($fb_user);

And the session is created in PHP. I want to use it with facebook javascript client library from here on out. How do I do this?

With this you can promote a session from PHP to JavaScript and from JavaScript to PHP using the Facebook->setSession() function

<?php

require 'facebook.php';

// Create our Application instance (replace this with your appId and secret).
$facebook = new Facebook(array(
'appId' => $appId,
'secret' => $secret,
'cookie' => true,
));

$_SESSION['facebook'] = $facebook;


// We may or may not have this data based on a $_GET or $_COOKIE based session.
//
// If we get a session here, it means we found a correctly signed session using
// the Application Secret only Facebook and the Application know. We dont know
// if it is still valid until we make an API call using the session. A session
// can become invalid if it has already expired (should not be getting the
// session back in this case) or if the user logged out of Facebook.
$session = $facebook->getSession();

$me = null;
// Session based API call.
if ($session) {
try {
$uid = $facebook->getUser();
$me = $facebook->api('/me');
} catch (FacebookApiException $e) {
//error_log($e);
}
}else{
  //pass in json object of FB._session and convert it to array
  $session = json_decode(stripslashes($_POST['session']));
  $session = (array) $session;


  if($session)
    $facebook->setSession($session);
}
?>

var constant = {};
constant.session = <?php echo json_encode($session); ?>;
window.fbAsyncInit = function() {
    FB.init({
      appId : '<?php echo $facebook->getAppId(); ?>',
      session : constant.session, // don't refetch the session when PHP already has it
      status : true, // check login status
      cookie : true, // enable cookies to allow the server to access the session
      xfbml : true // parse XFBML
    });
    if(!FB._session)
      stream.load();
    else
      jwpage.getAlbums();
    // whenever the user logs in, we refresh the stream
    FB.Event.subscribe('auth.login', function() {
      jwpage.getAlbums();
    });
  };

  (function() {
    var e = document.createElement('script');
    e.src = document.location.protocol + '//connect.facebook.net/en_US/all.js';
    e.async = true;
    document.getElementById('fb-root').appendChild(e);
}());
</script>