What is the best practice for extending a component?

I have been searching for how to extend and customize existing ember component but could not find something useful.

I found this http://emberjs.jsbin.com/vicojere/4/edit but it seems not good solution and it uses templateName inside component which is deprecated.

Any recommendations ?

You can pretty much do like this:

App.TextAreaComponent = Ember.TextArea.extend

and hook on to various events that ember provides like so

initializeDropDown: ( ->

I need to extend a custom component not existing one. exactly like the example i have provided.