I've come across what I think is surprising behavior for dependentObservables, they actually don't call notifySubscribers on write. They only call them the first time they are read.
I have created a simple example at
http://jsfiddle.net/studgeek/85aEN/ based on the discussion in
https://groups.google.com/d/topic/knockoutjs/NhLtoFJpwpU/discussion talks about this issue as well.
I'm wondering why this is, it seems there is an assumption that you will always have an underlying observable which seems a to be an unnecessary and a limiting design. There are cases where you don't own the underlying state, in those cases
to properly bind to that state you either have to copy the state to an
observable or create a fake observable that you trigger on each write.
Also, if dependentObservables don't notifySubscribers on write, why do they even bother to do it on read? They get added to the observables list and subscribed to, but then they never trigger on updates. So what is the point of subscribing to them at all?
Is there some downside to calling notifySubscribers in the write that I am missing?
Thanks,
d