Question

In my iOS application, when the user pushes a button in a view, a NSTimer is trigered in the controller.
On the third tick, I would like to make the background of the view bliking.

I’ve written the blinking function in the view (it should’t be written in the controller, should it ?)

I can trigger this blinking function in the controller by

LostView *lostView = (LostView* ) self.view;
[lostView blinkBackground];

But it’s bad, isn’t it ? The controller shoudn’t know the view neither the name of the function ?
I would like to apply the MVC pattern

Is the observer/obervable pattern applicable in this situation ?

Thanks

Answer 1

No it’s not bad at all. It looks like you implemented the method to make the view blink in the view itself. That’s fine, because it’s directly related to the visual representation (i.e. the view part of MVC). You could reuse that view in any other app that requires a blinking view.

Since that blinking is triggered by an NSTimer I assume that it’s somehow dependent on the logic in this specific app. The view can’t (shouldn’t) know when it’s supposed to blink (that would only be the case if that blinking was a direct reaction of an interaction with it or another related part of the UI – or it was part of a more complex element, for example a countdown timer that always starts to blink when it reaches the last 10 secs or so. For example the UIButton provides the possibility to highlight it self if it’s touched.)

But if that blinking is a reaction of some state transition in your app, maybe some new data becomes available or a countdown is about to expire, the controller is a perfectly reasonable place to trigger that.