Facebook App Development Brick Wall

Mr E

Hi all,

I'm trying to develop a facebook app for our software, but I'm falling at the first hurdle (getting a basic "hello world" app working). The developer documentation is awful, and the error I'm getting is so vague that I don't know how to move forward with this.

The error I'm getting is "The URL returned HTTP code 200 and no data."

My simple app (with sensitive info removed) is:

[PHP]<?php

require 'facebook.php';

// Create our Application instance.
$facebook = new Facebook(array(
'appId' => 'myid',
'secret' => 'mysecret',
'cookie' => true,
));


$session = $facebook->getSession();

if (!$session) {

$url = $facebook->getLoginUrl(array('canvas' => 1,'fbconnect' => 0));

echo "<script type='text/javascript'>top.location.href = '$url';</script>";

} else {

try {

$uid = $facebook->getUser();
$me = $facebook->api('/me');

$updated = date("l, F j, Y", strtotime($me));

echo "Hello " . $me . "<br />";
echo "You last updated your profile on " . $updated;

} catch (FacebookApiException $e) {

echo "Error:" . print_r($e, true);

}
}

?>[/PHP]

The code above was taken from a message board post I found (with lots of positive feedback from others to say it worked for them). I'm using the latest facebook.php from their SDK, and the canvas URL is running on PHP5 (phpinfo says its 5.1.6) and CURL is enabled.

Googling the "200 No data" error above, some people seem to think it might be timeout related, but I don't think so (it comes up pretty quickly). I've tried it now on 2 different hosting providers in Ireland, and both can't be timing out.

Does anyone have any ideas on how to get this working?

Webmonkey

Is HTTP 200 not an "Okay" response. You just don't print any data. I'm guessing that is.

Mr E

Thanks for the reply, webmonkey.

I'm echoing stuff to the screen (echo "Hello" etc.)

If I just do <?php echo "Hello"; ?> it works.
It seems to be the facebook session stuff that's tripping me up.

I was playing about more with it tonight. I can get the session stuff working with JQuery (so I'm not using PHP at all). The problem is that it works from my canvas URL (the external link), but not while run from the internal apps.facebook.com link (I just get the facebook header and a white screen)

Webmonkey

Mr E wrote: »

Thanks for the reply, webmonkey.

I'm echoing stuff to the screen (echo "Hello" etc.)

If I just do <?php echo "Hello"; ?> it works.
It seems to be the facebook session stuff that's tripping me up.

I was playing about more with it tonight. I can get the session stuff working with JQuery (so I'm not using PHP at all). The problem is that it works from my canvas URL (the external link), but not while run from the internal apps.facebook.com link (I just get the facebook header and a white screen)

Maybe your scripts arn't getting loading correctly within facebook? Could be security or paths or something. Check the error console in your browser to see.