Adding Post Titles to Parse.com database

I’m currently trying to add objects to a Parse database when i create a new post. Obviously, that makes sense right? Everytime I post a new post a new object is created in the database….well I can’t figure out how to do something that simple…

The steps i’ve taken so far is altering the post.php per the wordpress documentation. So i inserted this code in the wp_insert_post function:

$className = "Posts";
$url = 'https://api.parse.com/1/classes/' . $className;
$appId = 'myIDNumbers here';
$restKey = 'myKeyNumbersHere';

$objectData = '{"postTitleString": "POST TITLE GOES HERE"}';

$rest = curl_init();
curl_setopt($rest,CURLOPT_URL,$url);
curl_setopt($rest,CURLOPT_PORT,443);
curl_setopt($rest,CURLOPT_POST,1);
curl_setopt($rest,CURLOPT_POSTFIELDS,$objectData);
curl_setopt($rest,CURLOPT_HTTPHEADER,
    array("X-Parse-Application-Id: " . $appId,
        "X-Parse-REST-API-Key: " . $restKey,
        "Content-Type: application/json"));

$response = curl_exec($rest);
echo $response;

So far when I inserted it in post.php it automatically updates the database every time the “new post” page loads not when a new post is inserted. My goal is to perform this action and include that new posts title when the publish button is clicked. Any suggestions?