I am writing an application where user can create their desired web-interface from the tools provided. I am providing them with several options to create multiple draggables and droppables and I want to store them in database when they design their interface. Is JSON good choice for the data-exchange in this case or simple implementation of some PHP code and/or some server-side scripting will serve better?
I would simply send the data as form data.
$.post(url, { key : value }, successHandler);
and then use php to read the form values from the post data and submit to database.
$_POST["key"]
Your question is way too broad to provide much more of an answer than this.