> On Sep 21, 2016, at 7:00 PM, Doug Hill <cocoa...@breaqz.com> wrote:
> As to the context type, I would be interested to know of cases where the 
> observer doesn't have control over the context. My understanding is that the 
> context is something that the observer sets itself when calling addObserver, 
> and it is passed back to itself in the above method call. So the observer 
> should know what kind of entity the context is, and can determine the best 
> way to compare this value.

Subclasses or superclasses can register observers, so it’s possible for your 
observer method to get called for observations that you didn’t create.

(The subclass case is less likely, because the subclass’s observer method 
should be handling that call and not calling super, but it’s good defensive 
coding practice to not rely 100% on that.)


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