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?

score 5 · Accepted Answer · edited May 23 '17 at 11:55

5

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.

edited May 23 '17 at 11:55

Community

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answered Dec 12 '12 at 15:32

Bergi

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2

If you would like to see how Ember implements this, see https://github.com/emberjs/ember.js/blob/master/packages/ember-runtime/lib/ext/function.js. Also note that if you conclude this is a not a good idea, Ember makes this behavior configurable by setting `Ember.EXTEND_PROTOTYPES` to false. – Luke Melia Dec 13 '12 at 12:17

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

1 Answers1