Send a personalized URL to Facebook friends from external website - facebook

Question

I'm developing a website with the following requirement:
Users may invite their facebook friends to visit the website
Invited friends receive a personalized URL that points back to the website (either a message, notification, request...doesn't matter)
Example flow:
1. John visits http://www.mysite.com
2. John clicks the Facebook connect button and logs in with his facebook credentials
3. John clicks 'invite friends' button. The friend selector dialog appears
4. John selects Mary and submits the invitation/request/message
5. Mary receives a link like: http://www.mysite.com?name=Mary
6. Mary clicks the link from within facebook and is redirected to the URL above
7. My site displays: "Hello Mary!", taking the name from the URL parameter
I already managed to make steps 1-4.
I'm asking about step 5. Is that possible at all? I know I can get the facebook IDs of the people selected in the multi-friend selector, and that I can make a FBQL query to retrieve the names of the people selected, but how to customize the URL sent?
Cheers,
Nacho

Answer 1

Well, if the user will be sending invitations for a bulk of friends then these invitations won't be "invitee unique" (As mentioned by #Jimmy). BUT you can still capture the unique "friend id" and (I suppose) name from the request itself!
What you need to do is the following:
When a friend clicks on the invitation, he/she will get redirected to the canvas page (or the bookmark page if it has been sit).
Along with the redirection you'll receive the invitation number (request id) here you can read this request and extract the "To" field from it and then redirect the friend to your website.
Something like:
<?php
if( isset($_REQUEST['request_ids']) ) {
// Requesting an application token
$APPLICATION_ID = "APP_D";
$APPLICATION_SECRET = "APP_SECRET";
$token_url = "https://graph.facebook.com/oauth/access_token?" .
"client_id=" . $APPLICATION_ID .
"&client_secret=" . $APPLICATION_SECRET .
"&grant_type=client_credentials";
$app_token = file_get_contents($token_url);
// You may have more than one request, so it's better to loop
$requests = explode(',',$_REQUEST['request_ids']);
foreach($requests as $request_id) {
// Get the request details using Graph API
$request_content = json_decode(file_get_contents("https://graph.facebook.com/$request_id?$app_token"), TRUE);
// An example of how to get info from the previous call
$to_name = $request_content['to']['name'];
// When all is done, delete the requests because Facebook will not do it for you!
$deleted = file_get_contents("https://graph.facebook.com/$request_id?$app_token&method=delete"); // Should return true on success
echo "<script>top.location.href='http://www.mysite.com?name=" . urlencode($to_name) . "'</script>";
}
}
?>
For more read the following:
Facebook Documentation
How To: Handle Application Requests Using The Facebook Graph API

Answer 2

When the referred user lands on your site, you either need to know their Facebook User ID or all the information you plan to show them. It's going to be easier and more extensible to use the User ID, and to get that you'll need to get that user to install your app before you can identify them, look up their name, and say "Hello Mary!"
What I'd do here is let the referring user share a link customized for him. So if I'm A, and I'm sharing with my friends, my link would look like http://www.somedomain.com/?ref=A. I share this, my friend B clicks the link. When B gets to the install screen, he installs, and now we know B's name, and since we have the ref parameter, we know he clicked my link. (This is how Groupon and Dropbox handle referral links.)
And to answer your question more clearly, no, invite links need to be the same for each invitation you send using the multi-friend selector, so per-invitee links are not an option.