Question

I’m using the request dialog to send an application request to my friends.

Now, I want to embed my id, through a URL so when he clicks the invite, it has to
take him to my app and should get a link like this in the address bar in my browser: apps.facebook.com/test?uid=1111111111

This uid is my uid, because I sent the invite to my friend.

How to do this?
Updated on 21/10/2011

<script>
  FB.init({
    appId  : 'YOUR_APP_ID',
    status : true,
    cookie : true,
    oauth: true
  });


  function sendRequestToManyRecipients() {
    FB.ui({method: 'apprequests',
      message: 'My Great Request',
    }, requestCallback);
  }

  function requestCallback(response) {
    // Handle callback here
  }
  function getMultipleRequests(requestIds) {
  FB.api('', {"ids": requestIds }, function(response) {
  console.log(response);
});
}
</script>

Answer 1

In Request Dialog properties, there’s the property data that can be used to embed your unique identifier.

When a user click the invitation notification, one (or more, if more than one friend invite hime) request_ids will be returned. Then you can use the request_ids to query data.

UPDATE: to put data in request:

 FB.ui({method: 'apprequests',
      message: 'My Great Request',
      data: 'hello'
    }, requestCallback);

UPDATE2

The FB invitation has several steps:

1) This function open a dialog for user (for example, user A) to select friends to invite:

 FB.ui({method: 'apprequests',
      message: 'My Great Request',
      data: 'hello'
    }, requestCallback);

2) After user A invite a friend, says, user B. User B will get a notification on his news feed.

3) User B click into the notification, and get redirected to the canvas page: apps.facebook.com/test?request_ids=xxxxxx

4) You use the request_ids to retrieve the invitation details, either by javascript

function getMultipleRequests(requestIds) {
  FB.api('', {"ids": requestIds }, function(response) {
  console.log(response);
});
}

or by server code(php here, but the same mechanics for other languages):

//get the request ids from the query parameter
   $request_ids = explode(',', $_REQUEST['request_ids']);

   //build the full_request_id from request_id and user_id 
   function build_full_request_id($request_id, $user_id) {
      return $request_id . '_' . $user_id; 
   }

   //for each request_id, build the full_request_id and delete request  
   foreach ($request_ids as $request_id)
   {
      echo ("reqeust_id=".$request_id."<br>");
      $full_request_id = build_full_request_id($request_id, $user_id);  
      echo ("full_request_id=".$full_request_id."<br>");

      try {
         $delete_success = $facebook->api("/$full_request_id",'DELETE');
         if ($delete_success) {
            echo "Successfully deleted " . $full_request_id;}
         else {
           echo "Delete failed".$full_request_id;}
        }          
      catch (FacebookApiException $e) {
      echo "error";}
    }