How do you replicate something like function(){ ... }.property() in javascript like in Ember.js?

Question

Ember uses something like:

val: function(){ 
    ...
}.property()

and things like:

func: function(){
}.observes('someValue')

I think the fact that you can add a property to the end of a function is quite neat and would like to replicated it.However, I could not find where either of those things are implemented in the source and am wondering if anyone knows?

Also, more importantly, what exactly is going on here?

Answer 1

It's one of the Functions methods, just like call or bind.

You can add other methods by extending the native Function.prototype object. Whether that is a good practice is discussable, though; also have a look at these articles.