AngularJS - Keep Checking Variable/Function

Question

I would like to know what is the best way to keep checking a variable in AngularJS.

I made a simple clicker game where the user keeps gathering gold, so I need to be constantly checking the number of gold so I can perform some functions accordingly. The only thing I know is $interval, but I don't know if that's the best way since I have to write a number of seconds.

Thank you in advance.

Answer 1

Wherever your variable is stored (controller/directive):

$scope.goldAmount = 0; // or whatever initial value you so desire

Set a watch function

$scope.$watch('goldAmount', function(newAmount, oldAmount){
  // Do something with the amount when it changes
});

$watch allows you to 'watch' any variable within your $scope and run a call back when it changes.

Docs can be found here:

https://docs.angularjs.org/api/ng/type/$rootScope.Scope