How to Draw Geojson in Apple Maps as Overlay Using Swift 3

How to draw GeoJSON in Apple Maps as overlay using Swift 3

In the first dictionary of features your coordinates key having 2D array, so you need to also add one more if let condition in your geometryObject.values for loop.

for obj in geometryObject.values {
    print(obj)
    if let type = obj as? String {
        typeData = type
    } 
    if let coordObj = obj as? [Double] {
        coord = Coordinates(latitude: coordObj[0], longitude: coordObj[1])
        coordData?.append(coord)
    }
    //Add one more if let condition
    if let coordObj = obj as? [[Double]] { 
        for coordinate in coordObj {
            let coord = Coordinates(latitude: coordinate[0], longitude: coordinate[1])
            coordData?.append(coord)
        }
    }
    geometries = Geometry(type: typeData, coordinates: coordData!)
}
let feature = Feature(type: type, properties: properties!, geometry: geometries!)
features.append(feature)

Draw GeoJson in Apple Maps as overlay

I've found a solution in case someone wants help too.

@interface HHLViewController

+ (NSArray *)countriesOverlays;

@end

@implementation HHLViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    NSArray *overlays = [HHLViewController countriesOverlays];
    [self.stateMapView addOverlays:overlays];
}

+ (NSArray *)countriesOverlays {
    NSString *fileName = [[NSBundle mainBundle] pathForResource:@"countries" ofType:@"json"];
    NSData *overlayData = [NSData dataWithContentsOfFile:fileName];

    NSArray *countries = [[NSJSONSerialization JSONObjectWithData:overlayData options:NSJSONReadingAllowFragments error:nil] objectForKey:@"features"];

    NSMutableArray *overlays = [NSMutableArray array];

    for (NSDictionary *country in countries) {

        NSDictionary *geometry = country[@"geometry"];
        if ([geometry[@"type"] isEqualToString:@"Polygon"]) {
            MKPolygon *polygon = [HHLViewController overlaysFromPolygons:geometry[@"coordinates"] id:country[@"properties"][@"name"]];
            if (polygon) {
                [overlays addObject:polygon];
            }

        } else if ([geometry[@"type"] isEqualToString:@"MultiPolygon"]){
            for (NSArray *polygonData in geometry[@"coordinates"]) {
                MKPolygon *polygon = [HHLViewController overlaysFromPolygons:polygonData id:country[@"properties"][@"name"]];
                if (polygon) {
                    [overlays addObject:polygon];
                }
            }
        } else {
            NSLog(@"Unsupported type: %@", geometry[@"type"]);
        }
    }

    return overlays;

}

+ (MKPolygon *)overlaysFromPolygons:(NSArray *)polygons id:(NSString *)title
{
    NSMutableArray *interiorPolygons = [NSMutableArray arrayWithCapacity:[polygons count] - 1];
    for (int i = 1; i < [polygons count]; i++) {
        [interiorPolygons addObject:[HHLViewController polygonFromPoints:polygons[i] interiorPolygons:nil]];
    }

    MKPolygon *overlayPolygon = [HHLViewController polygonFromPoints:polygons[0] interiorPolygons:interiorPolygons];
    overlayPolygon.title = title;

    return overlayPolygon;
}

+ (MKPolygon *)polygonFromPoints:(NSArray *)points interiorPolygons:(NSArray *)polygons
{
    NSInteger numberOfCoordinates = [points count];
    CLLocationCoordinate2D *polygonPoints = malloc(numberOfCoordinates * sizeof(CLLocationCoordinate2D));

    NSInteger index = 0;
    for (NSArray *pointArray in points) {
        polygonPoints[index] = CLLocationCoordinate2DMake([pointArray[1] floatValue], [pointArray[0] floatValue]);
        index++;
    }

    MKPolygon *polygon;

    if (polygons) {
        polygon = [MKPolygon polygonWithCoordinates:polygonPoints count:numberOfCoordinates interiorPolygons:polygons];
    } else {
        polygon = [MKPolygon polygonWithCoordinates:polygonPoints count:numberOfCoordinates];
    }
    free(polygonPoints);

    return polygon;
}
@end

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