image link - https://drive.google.com/open?id=1BuVqFPaOEwnT8-ygFhuqOGJrEOiMfIbn

Now as we can see in image here we have to import data from spread sheet and check for any duplicate entry dynamically i.e.; based on the option selected from drop down and decide whether to add new lead or update the existing one.

Now how to write the controller logic and use ajax call in this case. And our template file is qweb.

Or any other approach one can tell apart from AJAX to deal with model in this case.