Pass a variable from an array to a Jquery POST method

Question

I'm trying to pass a variable inside a Jquery POST method from an object array that I get from an asynchronous IndexedDB call using YDN-DB. Basically db.values, returns an object array of records stored with information I want to send to a PHP script. I can access the ID or any other field of the record set like r[i].id. The only problem is that I can't access it from the inside of the POST's DONE method so I can delete the record by its ID after it was successfully processed by the PHP script.

Below is what I want to achieve, everything works fine, the only problem is when I try to delete the processed record:

var req = db.values('table');
req.done(function(r){
    for(i=0;i<r.length;r++){
        var post = $.post('myscript.php', {'sale[]': $.toJSON(r[i])});
        post.done(function(data){
            if(data == 'ok'){
                db.remove('table',r[i].id);
            }
        });
    }
});

Is there a way to do this, and get the ID of the processed record to be deleted instead using its array's position?

Thanks!

Answer 1

The problem is that the closure for the callback function captures the same i variable for all iterations, so when the callsbacks are called the value of i has passed the last item of the array. You can wrap the code in the loop inside a function to create a separate i variable for each iteration:

var req = db.values('table');
req.done(function(r){
  for(i=0;i<r.length;r++){

    (function(i){

      var post = $.post('myscript.php', {'sale[]': $.toJSON(r[i])});
      post.done(function(data){
        if(data == 'ok'){
            db.remove('table',r[i].id);
        }
      });

    })(i);

  }
});