Facebook Signed in request / fangate not working. Undefined index/offset errors

Question

I'm creating a facebook tab page and I would like to use fan gating.

I've used fan gating before and have had no problems, but this was like 4 months ago. And I'm using the same PHP but this time I'm getting problems.

See below the basic code for my app and the fan gate conditional statement...

But I get this error for some reason...

Notice: Undefined index: signed_request in /home/sites/example.co.uk/www/competition/index.php on line 126 Notice: Undefined offset: 1 in /home/sites/example.co.uk/www/competition/index.php on line 128 Like

Weird..

I've never had problems with using this before, has facebook changed the way this works?

Any help would be much a appreciated thanks.

<?php

$fb_app_id   = '000000000000000';           
$fb_secret   = '00000000000000000000000000000000';
$fb_app_url  = 'http://example.co.uk/competition';  
$fb_tab_url  = 'http://www.facebook.com/example/app_000000000000000';
$fb_channel  = '//example.co.uk'

require 'src/facebook.php';

//Create facebook application instance.
$facebook = new Facebook(array(
  'appId'  => $fb_app_id,
  'secret' => $fb_secret,
  'cookie' => true,
));

?>

<!DOCTYPE html>
<html>
<head>

    <meta property="fb:app_id" content="<?php echo $fb_app_id ?>" />

</head>

<body>

    <div id="fan-gate">

        <?php

            $signed_request = $_REQUEST["signed_request"];

            list($encoded_sig, $payload) = explode('.', $signed_request, 2);

            $data = json_decode(base64_decode(strtr($payload, '-_', '+/')), true);

            if (empty($data["page"]["liked"])) {

        ?>

            LIKE US...      

        <?php } else { ?>

            <strong>YOU'VE LIKED OUR PAGE, THANKS!!!</strong>

        <?php } ?>

    </div>

    <div id="fb-root"></div>

    <script>

        window.fbAsyncInit = function() {
            FB.init({
                appId: '<?php echo $fb_app_id ?>',
                channelUrl : '<?php echo $fb_channel ?>/channel.html', // Channel File
                cookie: true,
                xfbml: true,
                oauth: true,
                status: true
            });
            FB.Canvas.setAutoGrow(true);
        };

    </script>

</body>
</html>

Also tried this, but it always just says the second condition, even tho I haven't like the page.

<?php

$fb_app_id   = '000000000000000';           
$fb_secret   = '00000000000000000000000000000000';
$fb_app_url  = 'http://example.co.uk/competition';  
$fb_tab_url  = 'http://www.facebook.com/example/app_000000000000000';
$fb_channel  = '//example.co.uk'

require 'src/facebook.php';

//Create facebook application instance.
$facebook = new Facebook(array(
  'appId'  => $fb_app_id,
  'secret' => $fb_secret,
  'cookie' => true,
));

?>

<!DOCTYPE html>
<html>
<head>

    <meta property="fb:app_id" content="<?php echo $fb_app_id ?>" />

</head>

<body>

    <div id="fan-gate">

        <?php

        $signed_request = $facebook->getSignedRequest();

        $like_status = $signed_request["page"]["liked"];

        if($like_status){

            echo 'LIKE US...';

        } else {

            echo '<strong>YOU'VE LIKED OUR PAGE, THANKS!!!</strong>';

        }

    ?>

    </div>

    <div id="fb-root"></div>

    <script>

        window.fbAsyncInit = function() {
            FB.init({
                appId: '<?php echo $fb_app_id ?>',
                channelUrl : '<?php echo $fb_channel ?>/channel.html', // Channel File
                cookie: true,
                xfbml: true,
                oauth: true,
                status: true
            });
            FB.Canvas.setAutoGrow(true);
        };

    </script>

</body>
</html>

score 0 · Answer 1 · answered Jun 25 '12 at 11:25

0

The only reason the signed_request could be missing would be because of a redirect. Make sure the your app isn't reloading or redirecting the iframe to another page on your site. The signed_request is only available on the initial page, unless you manually pass it between pages.

answered Jun 25 '12 at 11:25

Niraj Shah

15,087
3
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PHP config change? Do a `var_dump( $_REQUEST );` on your page and see what you get. – Niraj Shah Jun 25 '12 at 13:47
Thank you for you help, but I tried my answer 'above' which seemed to work fine, and alot less code. – Joshc Jun 25 '12 at 14:21

score 0 · Answer 2 · answered Jun 25 '12 at 14:20

I managed to get fan-gating to work this way.

Seems alot more simple and works fine too.

Also I'm treating page admins like 'like' fans...

<?php

$fb_app_id   = '000000000000000';           
$fb_secret   = '00000000000000000000000000000000';
$fb_app_url  = 'http://example.co.uk/competition';  
$fb_tab_url  = 'http://www.facebook.com/example/app_000000000000000';
$fb_channel  = '//example.co.uk'

require 'src/facebook.php';

//Create facebook application instance.
$facebook = new Facebook(array(
  'appId'  => $fb_app_id,
  'secret' => $fb_secret,
  'cookie' => true,
));

$signedRequest = $facebook->getSignedRequest();

?>

<!DOCTYPE html>
<html>
<head>

    <meta property="fb:app_id" content="<?php echo $fb_app_id ?>" />

</head>

<body>

    <div id="fan-gate">

        <?php if ( ( $signedRequest['page']['liked'] || $signedRequest['page']['admin'] ) == 1 ) { ?>

            Like us...

        <?php } else { ?>

            <strong>You've Liked our page</strong>

        <?php } ?>

    </div>

    <div id="fb-root"></div>

    <script>

        window.fbAsyncInit = function() {
            FB.init({
                appId: '<?php echo $fb_app_id ?>',
                channelUrl : '<?php echo $fb_channel ?>/channel.html', // Channel File
                cookie: true,
                xfbml: true,
                oauth: true,
                status: true
            });
            FB.Canvas.setAutoGrow(true);
        };

    </script>

</body>
</html>

Facebook Signed in request / fangate not working. Undefined index/offset errors

2 Answers2