I need to try to notify a users who are modifying the same page that an update was made to an Excel grid SPA. I was thinking about passing pack and forth the date modified timestamp and if the original is in the past from the current in the database it would mean the grid was updated by someone else. Is there a better way to do this?
Since you've mentioned AJAX, I'll assume this is a web application. This sounds like an excellent candidate for bi-directional communication via websockets. I've used SignalR with great success. It will allow you to publish events from the server to any subscribed clients, allowing you to easily update what they are viewing.