angularjs - Usecase for $emit rather than directly accessing parent scope -

i'm struggling understand why you'd need use $emit rather using controller syntax , directly accessing & updating data on parent scope. use cases?

it's more efficient call method on parent scope directly, rather using $emit (or $broadcast) dispatch event. there valid reasons it.

here's reasons come mind:

• you want emit event more 1 application component can receive/process.
• you want de-couple components in future message may processed different controller (or maybe service or directive, etc.).
• you want emit event service/factory can consume (these not associated view/$scope, can inject $rootscope them).