#mage-event-manager.js

dot-notation event emission

What does that mean?

Standard javascripts objects use a dot-notation to denote hierarchy. For example:

food.soup.chickenNoodle

The parent object: food has a child object: stew which has a child object: chickenNoodle

With the event manager, you can emit events at every level of the hierarchy.

emit('food.soup.chickenNoodle');

Will emit at food.soup.chickenNoodle, food.soup, and food. So if you want to listen for all events related to food, you could listen on food and your event listener would trigger on food.pasta.macaroni, food.canned.pears, and food. If you only care about soup, you could listen only on food.soup and then you'd only hear about food.soup.minestrone, food.soup.tomato, and food.soup