Difference between reopenClass and direct assignment?

[pixelcort]

I'm curious as to the difference between

App.MyClass.reopenClass({key:'value'});

and

App.MyClass.key = 'value';

Is the former just a way to set a bunch of properties on the class, or does it actually do something more interesting?

[raycohen]

using reopenClass will allow the property to survive to subclasses, and therefore also be accessible from the instance of a subclass

http://jsfiddle.net/raycohen/t7tPQ/

[pixelcort]

Doesn't seem to work:

OuterClass=Em.Object.extend()
InnerClass=OuterClass.extend()
OuterClass.a=1
OuterClass.reopenClass({b:2})

now: InnerClass.a properly returns undefined, however InnerClass.b should return 2 but is returning undefined.

however, if I do this:

OuterClass=Em.Object.extend()
OuterClass.a=1
OuterClass.reopenClass({b:2})
InnerClass=OuterClass.extend()

now InnerClass.b properly returns 2.

Is it expected behavior that one needs to use reopenClass before subclassing, or is that a bug?

[wagenet]

@pixelcort, what @raycohen is saying is that subclasses don't receive properties not defined via reopenClass. I've made it a bit more clear here: http://jsfiddle.net/t7tPQ/1/

It seems like you were expecting it to modify subclasses if you call reopenClass on the parent after subclasses are defined. This is not a behavior I would expect. Also, in your first example, I can't see how InnerClass.a would return 1. In my tests it doesn't: http://jsfiddle.net/t7tPQ/2/

I think that we've been able to demonstrate how reopenClass is different than defining directly. And I've confirmed that there is no bug in this behavior. As a result, I'm closing this.

[pixelcort]

@wagenet, I specifically said that InnerClass.a properly returns undefined. I was never expecting it to return 1. I also understood @raycohen.

I see now that the intended purpose of reopenClass is to be used before subclassing. I would have closed this issue but you apparently already closed it for me.

[wagenet]

@pixelcort Sorry, I guess I misunderstood you. Glad we got it sorted out though.