title: How Controller convert JSON data from AJAX to Model instance?
body: <p>Just out of curiosity. I observed that when I make POST method in AJAX. I always mention <code>datatype:'json'</code> and it actually works with my model instance in parameter in Controller - The URL path  mentioned in AJAX. But, at the same time when I was sending data to JQGrid I needed JSON return type controller to send data in JSON format.</p>
  <p>How could model type method can auto-adjust itself with JSON format data?</p>