Don’t use this pattern – This will end up causing more errors than it solves. Even though you think it fixed something, it didn’t.
You can check if a $digest is already in progress by checking $scope.$$phase.
if(!$scope.$$phase) {
//$digest or $apply
}
$scope.$$phase will return "$digest" or "$apply" if a $digest or $apply is in progress. I believe the difference between these states is that $digest will process the watches of the current scope and its children, and $apply will process the watchers of all scopes.
To @dnc253’s point, if you find yourself calling $digest or $apply frequently, you may be doing it wrong. I generally find I need to digest when I need to update the scope’s state as a result of a DOM event firing outside the reach of Angular. For example, when a twitter bootstrap modal becomes hidden. Sometimes the DOM event fires when a $digest is in progress, sometimes not. That’s why I use this check.
I would love to know a better way if anyone knows one.
From comments: by @anddoutoi
- Don’t do
if (!$scope.$$phase) $scope.$apply(), it means your$scope.$apply()isn’t high enough in the call stack.