Im using Facebook C# SDK to post and fetch data. These simple tasks took forever to get running properly. Now I need to notify my webpage(ASP.NET C#) about changes on the specific facebook page so the webpage knows then it should fetch new data.
I have looked at this page : https://developers.facebook.com/docs/graph-api/real-time-updates/v2.2
But as usally with facebook documentations it misses to explain in detail how it works and how to get it working. Where exacly do I create the subscriptions? It says /{app-id}/subscriptions but I have tried this url with my app-id but no page is found?
I have tried to find examples on how to set this up but to no sucess.
Could someone please explain how this works? What do I need to do exacly to get this running?
Facebook subscription works by pinging a URL you own every time data has changed. You need to add a URL you own as a callback URL for Facebook subscriptions to work with
POST /v2.2/{app-id}/subscriptions HTTP/1.1
Host: graph.facebook.com
object=page
callback_url=http%3A%2F%2Fexample.com%2Fcallback%2F
fields=feed
verify_token=thisisaverifystring
In the above API request a POST request is made to add http://example.com/callback/ as the callback URL subscribing to the feed edges of the page object (a page object that the session user owns)
In your callback URL you must have it handle two actions
- the initial callback (Handling Verification Requests via the verify token)
- saving updated subscriptions (Receiving the Real Time Updates)
Here is an example of what it looks like in PHP
<?php
if ($_REQUEST['hub_verify_token'] === 'thisisaverifystring') {
echo $_REQUEST['hub_challenge'];
}
$file = 'sample.txt';
$inputJSON = json_decode(file_get_contents('php://input'));
file_put_contents($file, file_get_contents('php://input') );
?>
