detect when angularjs route controller goes out of scope?

Question

I have a controller that is attached to a route. The controller constantly polls the server using $timeout. When the route changes, I need to stop polling, and start it again when the route changes back.

Please help.

Here is my code:

(angular
 .module('app.controllers', ['ng', 'ngResource'])
 .controller('myContr', [
     /******/ '$scope', '$resource', '$timeout',
     function ($scope,   $resource,   $timeout) {
         function update() {
             $resource('my-service').get({}, function (d) {
                 // ...use data...
                 $timeout(update, UPDATE_INTERVAL);
             });
         };
         update();
     }
 ])
);

Answer 1

• Save the return value (a promise) from $timeout (to a $scope property).
• Register a $destroy event handler on your scope.
• Call cancel() on that $timeout promise when the event handler triggers.

When the route changes back, the controller will get recreated, so your existing code should start up the polling again.