$ rootScope. $ emit doesn't work

I am trying to pass an event in AngularJS to a second controller using:

First controller:

    $scope.checkThemeContent = function(theme) {
    console.log("Trying to get cards for theme id: " +theme.id);
    console.log(theme);

    $scope.selectedTheme = theme;

    if(theme.count_of_cards >0) {
        //$scope.$emit('detailDisplayed', {});
        $scope.displayedTemplate = 'detail';
        $rootScope.$emit('detailDisplayed', {});
    } else {
        $scope.displayedTemplate = 'empty';
    }
};

      

        
        
        
      

    

Second controller:

 $rootScope.$on('detailDisplayed', function(event, args) {
        alert('Received');
        $scope.initDataGrid();
    });

      

        
        
        
      

    

But the event doesn't fire.

I've tried scoping backwards and it works.

Where could the problem be?

I followed this tutorial:

http://toddmotto.com/all-about-angulars-emit-broadcast-on-publish-subscribing/

Thanks for any help.