[ios, macos] Add feature initializer

This adds a features initializer to MGLGeoJSONSource. The initializer
takes shapes and converts them to JSON representation before passing
to core. This also adds methods to the MGLShape concrete subclasses
so that they can represent themselves in NSDictionary form suitable
for transforming to JSON (GeoJSON).

1 files changed, 25 insertions, 0 deletions

diff --git a/platform/darwin/src/MGLPolyline+MGLAdditions.m b/platform/darwin/src/MGLPolyline+MGLAdditions.m
new file mode 100644
index 0000000000..e91e4fc192
--- /dev/null
+++ b/platform/darwin/src/MGLPolyline+MGLAdditions.m
@@ -0,0 +1,25 @@
+//
+//  MGLPolyline+MGLPolyline_MGLAdditions.m
+//  ios
+//
+//  Created by Mapbox on 9/30/16.
+//  Copyright © 2016 Mapbox. All rights reserved.
+//
+
+#import "MGLPolyline+MGLAdditions.h"
+
+@implementation MGLPolyline (MGLAdditions)
+
+- (NS_ARRAY_OF(id) *)mgl_coordinates {
+    
+    NS_MUTABLE_ARRAY_OF(NS_ARRAY_OF(NSNumber *) *) *coordinates = [NSMutableArray array];
+    
+    for (NSUInteger index = 0; index < self.pointCount; index++) {
+        CLLocationCoordinate2D coordinate = self.coordinates[index];
+        [coordinates addObject:@[@(coordinate.longitude), @(coordinate.latitude)]];
+    }
+    
+    return coordinates;
+}
+
+@end