如何将数据从隔离范围传递到父范围？

I am fairly new to using AngularJS, and what I am trying to do is create a directive and call functions from the parent scope within it. I am able to accomplish this, but what I can't seem to figure out is how to pass data from the isolate scope via an expression to the parent scope. The explanation of this in the Angular Developer guide is a little confusing.I am fairly new to using AngularJS, and what I