Store CLLocationCoordinate2D to NSUserDefaults

Question

I am new to iphone development, and i want to store CLLocationCoordinate2D object to NSUserDefaults. I am Trying

    [defaults setObject:location forKey:@"userLocation"];

But it gives error 'Sending CLLocationCoordinate2D to parameter of incompatible type id'

So How to store CLLocationCoordinate2D into NSUserDefaults? Thanks.

Toseef Khilji · Accepted Answer · 2018-10-31T03:48:36.923

As pdrcabrod said,

"A default object must be a property list, that is, an instance of NSData, NSString, NSNumber, NSDate, NSArray, or NSDictionary."

I use this to store,

    NSNumber *lat = [NSNumber numberWithDouble:location.latitude];
    NSNumber *lon = [NSNumber numberWithDouble:location.longitude];
    NSDictionary *userLocation=@{@"lat":lat,@"long":lon};

    [[NSUserDefaults standardUserDefaults] setObject:userLocation forKey:@"userLocation"];
    [[NSUserDefaults standardUserDefaults] synchronize];

And access using,

    NSDictionary *userLoc=[[NSUserDefaults standardUserDefaults] objectForKey:@"userLocation"];
    NSLog(@"lat %@",[userLoc objectForKey:@"lat"]);
    NSLog(@"long %@",[userLoc objectForKey:@"long"]);

should be `NSNumber *lat = [NSNumber numberWithDouble:location.coordinate.latitude]; NSNumber *lon = [NSNumber numberWithDouble:location.coordinate.longitude]; ` — imcc, Mar 15 '15 at 08:41

score 14 · Answer 2 · edited Feb 12 '15 at 09:00

14

This is what i would do:

NSData *data = [NSData dataWithBytes:&coordinate length:sizeof(coordinate)];
[[NSUserDefaults standardUserDefaults] setObject:data forKey:@"key"];
[[NSUserDefaults standardUserDefaults] synchronize];

Then you can retrieve it like this:

NSData *data = [[NSUserDefaults standardUserDefaults] objectForKey:@"key"];
CLLocationCoordinate2D coordinate;
[data getBytes:&coordinate length:sizeof(coordinate)];

edited Feb 12 '15 at 09:00

Yuichiro Suzuki

29
5

answered Sep 20 '13 at 07:09

Andrey Chernukha

21,488
17
97
161

Thanks for the answer! Be careful using this to store CLLocation object, you might get "EXC_BAD_ACESS code = 1" errors associated with converting a Core Foundation pointer to a Objective-C pointer, which you will later have trouble using because in some instances the object it points to will already be released. See this post... http://stackoverflow.com/a/27848617/4018041 – serge-k Jun 30 '15 at 18:59
FormigaNinja, you're being sarcastic, right? If the size of the structure will change the data may not be restored properly afterwards. – Nikita Ilyasov Mar 08 '16 at 22:21

score 3 · Answer 3 · answered Jun 08 '18 at 12:02

import CoreLocation

// Store an array of CLLocationCoordinate2D
func storeCoordinates(_ coordinates: [CLLocationCoordinate2D]) {
let locations = coordinates.map { coordinate -> CLLocation in
    return CLLocation(latitude: coordinate.latitude, longitude: coordinate.longitude)
}
let archived = NSKeyedArchiver.archivedData(withRootObject: locations)
UserDefaults.standard.set(archived, forKey: "coordinates")
UserDefaults.standard.synchronize()
}

// Return an array of CLLocationCoordinate2D
func loadCoordinates() -> [CLLocationCoordinate2D]? {
guard let archived = UserDefaults.standard.object(forKey: "coordinates") as? Data,
    let locations = NSKeyedUnarchiver.unarchiveObject(with: archived) as? [CLLocation] else {
        return nil
}

let coordinates = locations.map { location -> CLLocationCoordinate2D in
    return location.coordinate
}
        return coordinates
}

Now Let's test the implementation:

let testCoordinates = [
CLLocationCoordinate2D(latitude: 0.123456789, longitude: 0.123456789),
CLLocationCoordinate2D(latitude: 1.123456789, longitude: 1.123456789),
CLLocationCoordinate2D(latitude: 2.123456789, longitude: 2.123456789)
]

self.storeCoordinates(testCoordinates)

let coordinates = loadCoordinates()
print(coordinates)

score 2 · Answer 4 · answered Sep 20 '13 at 06:55

2

The NSUserDefaults class provides convenience methods for accessing common types such as floats, doubles, integers, Booleans, and URLs. A default object must be a property list, that is, an instance of (or for collections a combination of instances of): NSData, NSString, NSNumber, NSDate, NSArray, or NSDictionary. If you want to store any other type of object, you should typically archive it to create an instance of NSData

See: NSUserDefaults

answered Sep 20 '13 at 06:55

pdrcabrod

1,467
1
14
22

thanks for reply, but now how to archive it to create an instance of NSData to store in NSUSERDEFAULTS. – Toseef Khilji Sep 20 '13 at 07:01

score 2 · Answer 5 · answered Sep 20 '13 at 07:06

You can set like this..

CLLocationCoordinate2D coordinate; // need to set your coordinate here

[[defaults setObject:[NSString stringWithFormat:@"%g",coordinate.latitude] forKey:@"latitude"] ];
[[defaults setObject:[NSString stringWithFormat:@"%g",coordinate.longitude] forKey:@"longitude"] ];

i Hope it helps.

score 1 · Answer 6 · answered Jun 04 '17 at 07:43

As others have said, first convert it into a Dictionary or Data object and then save it as you normally would. In Swift I highly recommend using extensions. Here's what I did:

extension CLLocationCoordinate2D {

    private static let Lat = "lat"
    private static let Lon = "lon"

    typealias CLLocationDictionary = [String: CLLocationDegrees]

    var asDictionary: CLLocationDictionary {
        return [CLLocationCoordinate2D.Lat: self.latitude,
                CLLocationCoordinate2D.Lon: self.longitude]
    }

    init(dict: CLLocationDictionary) {
        self.init(latitude: dict[CLLocationCoordinate2D.Lat]!,
                  longitude: dict[CLLocationCoordinate2D.Lon]!)
    }

}

Store CLLocationCoordinate2D to NSUserDefaults

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