How to prevent a delegate method running?

Question

I am extending the weather app that we had to build in the networking programming course. I have implemented location detection however, I am tying to add a settings view controller where the user can change his/her location there. Every time my initial view controller loads, it runs a delegate method which sets the coordinate value. So how would you change the coordinate value from a different view controller if it automatically sets it in the previous controller. My code for my main view (view did load method is shown below:

override func viewDidLoad() {
    super.viewDidLoad()
    locationManager.delegate = self
    locationManager.desiredAccuracy = kCLLocationAccuracyBest
    locationManager.requestWhenInUseAuthorization()
    locationManager.startUpdatingLocation()
}

I have tried setting the delegate in the prepageForSeuge as nil however every time the view loads again, it just resets it. Any idea how I could solve this?

Answer 1 · 2016-07-17T14:32:28Z

July 17, 2016 2:32pm

Hey Amir Gamil,

You're going to want to do a few things. First would be to remove start updating location from viewDidLoad. You only want to call this method if the user has not set a specific location for the app to use. I would try something simple at first, maybe using NSUserDefaults.

/// When a user sets a latitude/longitude in settings, store them in the NSUserDefaults using a key
NSUserDefaults.standardUserDefaults.setValue(20, forKey: "longitude")
NSUserDefaults.standardUserDefaults.setValue(40, forKey: "latitude")

/// Then in viewDidLoad you can check
func locationIsSet() -> Bool {
    let lon = NSUserDefaults.standardUserDefaults.valueForKey("longitude")
    let lat = NSUserDefaults.standardUserDefaults.valueForKey("latitude")
    return lat != nil && lon != nil
}

if locationIsSet {
    /// use locations from defaults
    locationManager.endUpdatingLocation()
} else {
    /// monitor for location
    locationManager.startUpdatingLocation()
}

I don't know if I'm using the proper method names but hopefully this gives you a general idea. There are many ways to go about this. Good Luck!

Answer 2 · 2016-07-17T14:56:59Z

July 17, 2016 2:56pm

Thanks for your help! I'd already found a solution but this could be a way to refactor my current code. :)

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Amir Gamil

Amir Gamil

How to prevent a delegate method running?

2 Answers

Steven Deutsch

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Amir Gamil

Amir Gamil