The function is to tell its parent $scope that an event has been triggered. The name of the event is boyslist, and the data is result.data

If your parent $scope is listening for this event, the callback function inside will be triggered, for example

$scope.$on('boyslist', console.log);

This will print it out

Scope Events Propagation
Scopes can propagate events in similar fashion to DOM events. The event can be broadcasted to the scope children or emitted to scope parents.

You can read this for details, and then look atScope Events Propagationthat little piece

Transfer child controller data to parent controller