Answer by Shawn Dotey for AngularJS : Prevent error $digest already in progress when calling $scope.$apply()

similar to answers above but this has worked faithfully for me... in a service add:

    //sometimes you need to refresh scope, use this to prevent conflict
    this.applyAsNeeded = function (scope) {
        if (!scope.$$phase) {
            scope.$apply();
        }
    };