Question

I have a upvote button, which the user can press and a vote will be registered. On clicking this button again, the vote gets cancelled.

So each press of this button is doing a DataBase Write. If an autoclicker is used on this button continuously, continuous DB calls will happen. I want to prevent this.
What can I do?

PS. I am sending an ajax query to the backend(running Django) when the upvote button is clicked.

Answer 1

You’d really want to check this on the server, so it doesn’t matter if someone disables javascript.

If you’re using PHP one option is to set a time limit between votes.. eg only allow one vote per minute.

So on every vote, store the time of the vote in a session variable, then ignore subsequent votes if it is within the time limit:

//on vote
$now=date('U');
if(!isset($_SESSION['lastvote']) || $now - $_SESSION['lastvote']<LIMIT){
    $_SESSION['lastvote']=$now;
    // do database call

}else{
    //throw error
}