title: Rails - override a setter for an active record attribute
body: <p>I am building a rails server in which some users follow changes in an other users location and get notified by websockets each time the location is updated.</p>
  
  <p>Currently I call an update_location action instead of calling regular update in order to update the location and call the WebsocketRais trigger. This seems really odd to me and I think there should be a better way.</p>
  
  <p>The only other option I know of is to call update action and check to see if the location is updated, and the notify the subscribers. This too seems very ugly to me.</p>
  
  <p>I would like to be able to somehow override the Rails update of the resource, and notify the subscribers each time the location attribute is updated - something like a setter method for the location attribute that does other things than just set. Is it even possible? how would I be able to do it?</p>