January 2012

How to check Facebook Page Liked by User, Like-Gate Facebook iFrame Tab using PHP Graph API

These days, every business wants more and more ‘Likes’ for their Facebook pages if their Facebook application supports its own custom tab. And this is kinda becoming the basic requirement for every such Facebook app these days so here’s how you can achieve that using Graph API PHP SDK. This helps us choosing the content which we show to the user and if he has not liked the page yet, we can ask the user to do that first.

 
require 'facebook.php';
 
$app_id = "your app id";
$app_secret = "your app secret";
$facebook = new Facebook(array(
    'appId' => $app_id,
    'secret' => $app_secret,
    'cookie' => true,
));
 
$signed_request = $facebook->getSignedRequest();
 
$like_status = $signed_request["page"]["liked"];
 
if ($like_status == 1){
echo 'User likes this page';
}
else{
echo 'User doesn\'t like this page';
}

You can check all the other data by printing the $signed_request array like this:

 
echo '<pre>';
print_r($signed_request);
echo '

‘;

Among other info, you can also retrieve the page ID of the current Facebook page using the above information from array. $signed_request['page']['id'] can help you in showing tab specific content.

Hope that helps.

Cheers!

Dynamically Resizing Facebook Canvas (iFrame) Apps to Remove Scrollbars

All new Facebook applications are now iFrame apps. But when you check your app using iFrame inside Facebook, horizontal and vertical scroll bars may appear in the iFrame if the content exceeds height and width of the
canvas. Luckily, Facebook provides a ready to use method to dynamically re-sizing of iFrame inside it.

Step 1

If you want to remove the horizontal and vertical scrollbars from your iFrame Facebook app, GO to your application developer page > app settings and in the “Edit settings” section of your app and change your “IFrame Size” to “Auto-resize” NOT “Show scrollbars.”

Step 2

Open your config file where you have defined other settings for your app and add following code:

 
<div id="fb-root"></div>
<script type="text/javascript">
    window.fbAsyncInit = function() {
        //Your app id must be added there to work
        FB.init({appId: 'your_app_id', status: true, cookie: true, xfbml: true});
        //Resize the iframe when needed
        FB.Canvas.setAutoResize();
    };
 
    //Load the JavaScript SDK asynchronously
    (function() {
        var e = document.createElement('script'); e.async = true;
        e.src = document.location.protocol + '//connect.facebook.net/en_US/all.js';
        document.getElementById('fb-root').appendChild(e);
    }());
</script>

Now your iframe FB App should resize automatically depending on the content. You can see the documentation of setAutoResize() method on Facebook wiki.

Hope that helps.

Cheers!

Get Facebook User’s Affiliations, Network Information Using Facebook Graph API

Facebook Graph API $me object does not provide user’s network info. To access FB user’s networks/affiliations information, you need to use FQL like this:

 
$fql  =  'SELECT affiliations, name FROM user WHERE uid = '.$me['id'];
 
//or use this query for standard_user_info table
//$fql = 'SELECT affiliations, name FROM standard_user_info WHERE uid = '.$me['id']; 
 
$param  =   array(
       'method'     => 'fql.query',
        'query'     => $fql,
      'callback'    => ''
);
$affiliations   =   $facebook->api($param);
 
echo '<pre>';
print_r($affiliations);
echo '

‘;

Hope that helps.