为stream.publish寻找图片附件php API feed

I am desperately looking for image attachment php api feeds for my facebook app.

Basically what I am trying to do is send an image attachment, along with an automatic "post to friends wall" action.

The idea behind it is that a user sends a "virtual burger" to their friends wall, with a message offering them a discount.

This is a snippet of the code that successfully sends the message, but I can't get the attachment to work.

if($_REQUEST['friend_1']!='' && $_REQUEST['friend_1']!="Start typing a friend's name") {
    try {
        $fql1    =   "select name from user where uid=" . $_REQUEST['friend_1'];
        $param1  =   array(
            'method'    => 'fql.query',
            'query'     => $fql1,
            'callback'  => ''
        );
        $fqlResult1   =   $facebook->api($param1);
        $friend_1_name = $fqlResult1[0]['name'];
        $statusUpdate = $facebook->api('/'.$_REQUEST['friend_1'].'/feed', 'post', array('link' => $fanpageURL, 'name' => 'Have a virtual Unity Burger.', 'description' => " ".$user_name." just sent you a virtual Unity Burger. If you would rather have the real thing then come add your name on the Unity list and we will give you a 20% discount on your next visit and an exclusive Unity keyring.", 'properties' => '', 'cb' => ''));
    } catch (FacebookApiException $e) {
        //echo "Notification not send to user ".$fqlResult1[0]['name']."<br>";

I think there are two ways to attach an image to a wall post.

The first one is to define the meta og:image in the target page and post the link to the friends wall. Facebook will query the target and grab the Open Graph info displaying it in the wall. You can test this with the Facebook Debugger.

The meta property should look like this:

<meta property="og:image" content="http://url.to/image" />

You can also define other Open Graph properties like title, description, etc.

The second way to attach the image to the post is to include the picture parameter in the Graph API call. In your code you only define some parameters (link, name, description...) but you can also send picture, caption, message...

So your API call could be like this:

$params = array(    'access_token' => '',
                    'message'   =>  '',
                    'link'      =>  '',
                    'picture'   =>  '',
                    'name'      =>  '',
                    'caption'   =>  '',
                    'description'   =>  ''
);

$wallPost = $facebook->api('/'.$to.'/feed', 'post', $params);