(First off, sorry for the long winded post title. It is basically what I google every time I’m trying to remember the functionality.)
Let’s say you have a directive that allows a user to enter data. When that user is done entering data, the directive processes the data, then sends the result back up to the parent. If we were to do this with two-way data binding, we’d have to set up watchers to know when the values were changed. There is a way to do it without the watchers though. We can use the parent scope binding type: “&”.