php - Creating a Form for a Competition that can only be submitted once per user -



php - Creating a Form for a Competition that can only be submitted once per user -

i've create facebook app 1 time user has liked page sent reveal page contains entry form competition,

is there method create user can submit form once?

is there method create user can submit form once?

i think first need authenticate user(facebook you?). assume using like below:

<?php $app_id = "your_app_id"; $canvas_page = "your_canvas_page_url"; $auth_url = "https://www.facebook.com/dialog/oauth?client_id=" . $app_id . "&redirect_uri=" . urlencode($canvas_page); $signed_request = $_request["signed_request"]; list($encoded_sig, $payload) = explode('.', $signed_request, 2); $data = json_decode(base64_decode(strtr($payload, '-_', '+/')), true); if (empty($data["user_id"])) { echo("<script> top.location.href='" . $auth_url . "'</script>"); } else { echo ("welcome user: " . $data["user_id"]); } ?>

then authorize user($data["user_id"]) if new user proceed. if not halt. can maintain track of users storing $data["user_id"] in database.

php facebook

Comments

Popular posts from this blog

iphone - Dismissing a UIAlertView -

intellij idea - Update external libraries with intelij and java -

javascript - send data from a new window to previous window in php -