How do I properly separate iOS networking code from view controllers?

Hi Matthew

That's a pretty big question in that, well, there are definitely a fair few different approaches you could take to setting up what you're after, but in short what you're suggesting is a great idea so hopefully I can at least help a little.

First off with regards to setting up a new class such as the potential "ForecastService" class you mentioned the best start is to take the S from SOLID and ensure that it only has a single responsibility. When you talked about it not feeling great that network requests were being handled in the view sounds completely right, what you'll want to do is move just that to it's own class from where you can then call it to do all of the dirty work for you, in your case getting the Stormy JSON back from the API, and then returning it to your view where you can then manipulate it. The benefit of this is that your new class and the methods within said class will be completely ignorant of what the data it is returning is going to be used for which is exactly how it should be.

There are an abundance of ways to go about getting the result you're after but the way I've found that works for me is making use of callbacks to ensure data is fully loaded before it being pushed to the UI. Perhaps the easiest way to show what I mean would be to have a look at what I currently have set up for one of my dev apps which is:

CloudKit Handling

Whilst the code is being used for CloudKit the concept of using callbacks in the way they're laid out in there are the same that you could use for your potential ForecastService class.
The code in the above link could do with some more refactoring so apologies if it's a little verbose. If there's anything there that catches your eye that you'd like some more info on then of course just let me know.

KR

Nick