Facebook Apps - How to post on friend's wall using Graph API

---

First you need to have PHP SDK to start with. You can download the PHP SDK for facebook at the following location:

https://github.com/facebook/php-sdk

Here is the sample code for Facebook Apps on how to post on Friend's wall using Graph API

    
    include_once 'facebook.php';

	$facebook = new Facebook(array(
		'appId' => 'YOUR_APP_ID',
		'secret' => 'YOUR_SECRET_KEY',
		'cookie' => true,
		'domain' => 'www.softwareandfinance.com'
	));

	$app_name = "Broadcast to Friends";
	$app_url = "http://apps.facebook.com/your_app_name/";

	$user_id = $facebook->getUser();

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

	} else 
	{
		try {
			$permissions = $facebook->api("/me/permissions");
			if(! array_key_exists('publish_stream', $permissions['data'][0]) ) { 
				header( "Location: " . $facebook->getLoginUrl(array("scope" => "publish_stream")) );
			} 

			$permissions = $facebook->api("/me/permissions");
	
			if( array_key_exists('publish_stream', $permissions['data'][0]) ) {
				$friends = array();
				$_friends = $facebook->api("/me/friends"); 
	
				if (is_array($_friends) && count($_friends)) {
					foreach ($_friends as $friend) { 
						$friends[] = $friend['uid'];
						$location = "/" . friend[uid] . "/feed";
						$post_id = $facebook->api($location, 'post', array('message'=>'Hello World!'));
						echo "posted on friend's wall" . $post_id;
					}
				}
			}

		} 
		catch (FacebookApiException $e) 
		{
			echo "Error: Unable to post on your friend's wall";

		}
	}