When trying to develop a Today Extension for iOS 8 I found a weird issue. It would seem that the View Controller I'm using is being recreated every time the user opens Notification Center. This means that there is no data retention and hence no way for me to know if the extension needs to update or not.
The main reason for wanting to do this is that I want to preserve the height of the widget (Using preferredContentSize). The problem is that when the view loads this value always gets reset which leads to the widget jumping around in size. The Stocks widget is an example of how it's supposed to work and they've obviously solved it so there has to be some way of retaining the data between different "sessions". I can also tell from the debugger that the process continues to run, so it's just down to something in Apple's code forcing the View Controller to be recreated.
My question is, is this a bug? Or is it based on some setting or some property that I'm missing? Or is it maybe just the way it's supposed to work? If so, what is the workaround?
That's the way they work. Save your information to the device so you can reload it the next time you launch, along with the update time so you know if it's out of date. For small amounts of data, just use NSUserDefaults. For larger amounts save to a file, CoreData, sqlite, etc.