[ios, macos] Put MGLStyleLayer inits in respective classes

Previously, we declared MGLStyleLayer initializers in the MGLStyleLayer
protocol as optional methods. This made it easy to opt in and out
of initializers that did or or did not make sense for the subclass.
However, this approach was dangerous since it was easy for an
application developer to initialize an MGLStyleLayer subclass with an
init method that was actually not implemented in that class causing
an exception at runtime.

This commit moves the init methods that each subclass supports to
each subclass so xcode (and the compiler) help the developer avoid
the previously possible runtime exception.

In addition, a new init method is added that takes the source layer
and passes that on to `mbgl::style:Layer` (but only on classes
where this is possible in core). This allows an application developer
to style a specific source layer (i.e. the contour lines of the mapbox
terrain vector source).

Finally, this refactors MGLStyleLayer classes to use an MGLSource instead of a
string identifier for the source when initializing the style.

27 files changed, 215 insertions, 38 deletions

diff --git a/platform/darwin/scripts/generate-style-code.js b/platform/darwin/scripts/generate-style-code.js
index 4a875f784a..e934b39da0 100644
--- a/platform/darwin/scripts/generate-style-code.js
+++ b/platform/darwin/scripts/generate-style-code.js
@@ -187,14 +187,26 @@ global.propertyType = function (property, _private) {
     return _private ? `id <MGLStyleAttributeValue, MGLStyleAttributeValue_Private>` : `id <MGLStyleAttributeValue>`;
 };
 
+global.initLayerIdentifierOnly = function (layerType) {
+    return `_layer = new mbgl::style::${camelize(layerType)}Layer(layerIdentifier.UTF8String);`
+}
+
 global.initLayer = function (layerType) {
     if (layerType == "background") {
-        return `_layer = new mbgl::style::${camelize(layerType)}Layer(layerIdentifier.UTF8String);`
+       return `_layer = new mbgl::style::${camelize(layerType)}Layer(layerIdentifier.UTF8String);` 
     } else {
-        return `_layer = new mbgl::style::${camelize(layerType)}Layer(layerIdentifier.UTF8String, sourceIdentifier.UTF8String);`
+        return `_layer = new mbgl::style::${camelize(layerType)}Layer(layerIdentifier.UTF8String, source.sourceIdentifier.UTF8String);`
     }
 }
 
+global.initLayerWithSourceLayer = function(layerType) {
+    return `_layer = new mbgl::style::${camelize(layerType)}Layer(layerIdentifier.UTF8String, source.sourceIdentifier.UTF8String);`  
+}
+
+global.setSourceLayer = function() {
+   return `_layer->setSourceLayer(sourceLayer.UTF8String);`
+}
+
 global.setterImplementation = function(property, layerType) {
     let implementation = '';
     switch (property.type) {
diff --git a/platform/darwin/src/MGLBackgroundStyleLayer.h b/platform/darwin/src/MGLBackgroundStyleLayer.h
index 0d99b38b6a..a6eda28783 100644
--- a/platform/darwin/src/MGLBackgroundStyleLayer.h
+++ b/platform/darwin/src/MGLBackgroundStyleLayer.h
@@ -8,6 +8,11 @@ NS_ASSUME_NONNULL_BEGIN
 
 @interface MGLBackgroundStyleLayer : MGLBaseStyleLayer <MGLStyleLayer>
 
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier;
+
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source;
+
+
 #pragma mark - Accessing the Paint Attributes
 
 #if TARGET_OS_IPHONE
diff --git a/platform/darwin/src/MGLBackgroundStyleLayer.mm b/platform/darwin/src/MGLBackgroundStyleLayer.mm
index adfa31e4ed..f15bc4ceed 100644
--- a/platform/darwin/src/MGLBackgroundStyleLayer.mm
+++ b/platform/darwin/src/MGLBackgroundStyleLayer.mm
@@ -1,6 +1,7 @@
 // This file is generated. 
 // Edit platform/darwin/scripts/generate-style-code.js, then run `make style-code-darwin`.
 
+#import "MGLSource.h"
 #import "NSPredicate+MGLAdditions.h"
 #import "MGLStyleLayer_Private.h"
 #import "MGLStyleAttributeValue.h"
@@ -13,6 +14,7 @@
 @property (nonatomic) mbgl::style::BackgroundLayer *layer;
 @property (nonatomic, readwrite) NSString *layerIdentifier;
 @property (nonatomic, readwrite) NSString *sourceIdentifier;
+@property (nonatomic, readwrite) NSString *sourceLayerIdentifier;
 
 @end
 
@@ -20,15 +22,26 @@
 
 @synthesize mapView;
 
-- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier sourceIdentifier:(NSString *)sourceIdentifier {
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier
+{
     if (self = [super init]) {
         _layerIdentifier = layerIdentifier;
-        _sourceIdentifier = sourceIdentifier;
         _layer = new mbgl::style::BackgroundLayer(layerIdentifier.UTF8String);
     }
     return self;
 }
 
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source
+{
+    if (self = [super init]) {
+        _layerIdentifier = layerIdentifier;
+        _sourceIdentifier = source.sourceIdentifier;
+        _layer = new mbgl::style::BackgroundLayer(layerIdentifier.UTF8String);
+    }
+    return self;
+}
+
+
 #pragma mark - Accessing the Paint Attributes
 
 - (void)setBackgroundColor:(id <MGLStyleAttributeValue, MGLStyleAttributeValue_Private>)backgroundColor {
diff --git a/platform/darwin/src/MGLBaseStyleLayer.mm b/platform/darwin/src/MGLBaseStyleLayer.mm
index a747467739..8aaabcc8a8 100644
--- a/platform/darwin/src/MGLBaseStyleLayer.mm
+++ b/platform/darwin/src/MGLBaseStyleLayer.mm
@@ -13,6 +13,32 @@
 @synthesize layerIdentifier;
 @synthesize mapView;
 @synthesize layer;
+@synthesize sourceIdentifier;
+@synthesize sourceLayerIdentifier;
+
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier
+{
+    [[NSException exceptionWithName:@"MGLAbstractClassException"
+                             reason:@"MGLBaseStyleLayer is an abstract class"
+                           userInfo:nil] raise];
+    return nil;
+}
+
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier sourceIdentifier:(NSString *)sourceIdentifier
+{
+    [[NSException exceptionWithName:@"MGLAbstractClassException"
+                             reason:@"MGLBaseStyleLayer is an abstract class"
+                           userInfo:nil] raise];
+    return nil;
+}
+
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier sourceIdentifier:(NSString *)sourceIdentifier sourceLayer:(NSString *)sourceLayer
+{
+    [[NSException exceptionWithName:@"MGLAbstractClassException"
+                             reason:@"MGLBaseStyleLayer is an abstract class"
+                           userInfo:nil] raise];
+    return nil;
+}
 
 - (void)setVisible:(BOOL)visible
 {
diff --git a/platform/darwin/src/MGLCircleStyleLayer.h b/platform/darwin/src/MGLCircleStyleLayer.h
index e4430044ad..bd51b8ede0 100644
--- a/platform/darwin/src/MGLCircleStyleLayer.h
+++ b/platform/darwin/src/MGLCircleStyleLayer.h
@@ -18,6 +18,11 @@ typedef NS_ENUM(NSUInteger, MGLCircleStyleLayerCirclePitchScale) {
 
 @interface MGLCircleStyleLayer : MGLBaseStyleLayer <MGLStyleLayer>
 
+
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source;
+
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source sourceLayer:(NSString *)sourceLayer;
+
 /**
  A predicate that corresponds to the layer's <a href='https://www.mapbox.com/mapbox-gl-style-spec/#types-filter'>filter</a>.
  
diff --git a/platform/darwin/src/MGLCircleStyleLayer.mm b/platform/darwin/src/MGLCircleStyleLayer.mm
index a906407486..1db7ef875e 100644
--- a/platform/darwin/src/MGLCircleStyleLayer.mm
+++ b/platform/darwin/src/MGLCircleStyleLayer.mm
@@ -1,6 +1,7 @@
 // This file is generated. 
 // Edit platform/darwin/scripts/generate-style-code.js, then run `make style-code-darwin`.
 
+#import "MGLSource.h"
 #import "NSPredicate+MGLAdditions.h"
 #import "MGLStyleLayer_Private.h"
 #import "MGLStyleAttributeValue.h"
@@ -13,6 +14,7 @@
 @property (nonatomic) mbgl::style::CircleLayer *layer;
 @property (nonatomic, readwrite) NSString *layerIdentifier;
 @property (nonatomic, readwrite) NSString *sourceIdentifier;
+@property (nonatomic, readwrite) NSString *sourceLayerIdentifier;
 
 @end
 
@@ -20,11 +22,24 @@
 
 @synthesize mapView;
 
-- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier sourceIdentifier:(NSString *)sourceIdentifier {
+
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source
+{
+    if (self = [super init]) {
+        _layerIdentifier = layerIdentifier;
+        _sourceIdentifier = source.sourceIdentifier;
+        _layer = new mbgl::style::CircleLayer(layerIdentifier.UTF8String, source.sourceIdentifier.UTF8String);
+    }
+    return self;
+}
+
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source sourceLayer:(NSString *)sourceLayer
+{
     if (self = [super init]) {
         _layerIdentifier = layerIdentifier;
-        _sourceIdentifier = sourceIdentifier;
-        _layer = new mbgl::style::CircleLayer(layerIdentifier.UTF8String, sourceIdentifier.UTF8String);
+        _sourceIdentifier = source.sourceIdentifier;
+        _layer = new mbgl::style::CircleLayer(layerIdentifier.UTF8String, source.sourceIdentifier.UTF8String);
+        _layer->setSourceLayer(sourceLayer.UTF8String);
     }
     return self;
 }
diff --git a/platform/darwin/src/MGLFillStyleLayer.h b/platform/darwin/src/MGLFillStyleLayer.h
index 2d51f071e5..823c0574af 100644
--- a/platform/darwin/src/MGLFillStyleLayer.h
+++ b/platform/darwin/src/MGLFillStyleLayer.h
@@ -13,6 +13,11 @@ typedef NS_ENUM(NSUInteger, MGLFillStyleLayerFillTranslateAnchor) {
 
 @interface MGLFillStyleLayer : MGLBaseStyleLayer <MGLStyleLayer>
 
+
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source;
+
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source sourceLayer:(NSString *)sourceLayer;
+
 /**
  A predicate that corresponds to the layer's <a href='https://www.mapbox.com/mapbox-gl-style-spec/#types-filter'>filter</a>.
  
diff --git a/platform/darwin/src/MGLFillStyleLayer.mm b/platform/darwin/src/MGLFillStyleLayer.mm
index 6867c50f16..d36375b126 100644
--- a/platform/darwin/src/MGLFillStyleLayer.mm
+++ b/platform/darwin/src/MGLFillStyleLayer.mm
@@ -1,6 +1,7 @@
 // This file is generated. 
 // Edit platform/darwin/scripts/generate-style-code.js, then run `make style-code-darwin`.
 
+#import "MGLSource.h"
 #import "NSPredicate+MGLAdditions.h"
 #import "MGLStyleLayer_Private.h"
 #import "MGLStyleAttributeValue.h"
@@ -13,6 +14,7 @@
 @property (nonatomic) mbgl::style::FillLayer *layer;
 @property (nonatomic, readwrite) NSString *layerIdentifier;
 @property (nonatomic, readwrite) NSString *sourceIdentifier;
+@property (nonatomic, readwrite) NSString *sourceLayerIdentifier;
 
 @end
 
@@ -20,11 +22,24 @@
 
 @synthesize mapView;
 
-- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier sourceIdentifier:(NSString *)sourceIdentifier {
+
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source
+{
+    if (self = [super init]) {
+        _layerIdentifier = layerIdentifier;
+        _sourceIdentifier = source.sourceIdentifier;
+        _layer = new mbgl::style::FillLayer(layerIdentifier.UTF8String, source.sourceIdentifier.UTF8String);
+    }
+    return self;
+}
+
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source sourceLayer:(NSString *)sourceLayer
+{
     if (self = [super init]) {
         _layerIdentifier = layerIdentifier;
-        _sourceIdentifier = sourceIdentifier;
-        _layer = new mbgl::style::FillLayer(layerIdentifier.UTF8String, sourceIdentifier.UTF8String);
+        _sourceIdentifier = source.sourceIdentifier;
+        _layer = new mbgl::style::FillLayer(layerIdentifier.UTF8String, source.sourceIdentifier.UTF8String);
+        _layer->setSourceLayer(sourceLayer.UTF8String);
     }
     return self;
 }
diff --git a/platform/darwin/src/MGLLineStyleLayer.h b/platform/darwin/src/MGLLineStyleLayer.h
index 5c2a3afc2e..34f8e74dfa 100644
--- a/platform/darwin/src/MGLLineStyleLayer.h
+++ b/platform/darwin/src/MGLLineStyleLayer.h
@@ -25,6 +25,11 @@ typedef NS_ENUM(NSUInteger, MGLLineStyleLayerLineTranslateAnchor) {
 
 @interface MGLLineStyleLayer : MGLBaseStyleLayer <MGLStyleLayer>
 
+
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source;
+
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source sourceLayer:(NSString *)sourceLayer;
+
 /**
  A predicate that corresponds to the layer's <a href='https://www.mapbox.com/mapbox-gl-style-spec/#types-filter'>filter</a>.
  
diff --git a/platform/darwin/src/MGLLineStyleLayer.mm b/platform/darwin/src/MGLLineStyleLayer.mm
index 8c5af877fe..b35d3921f5 100644
--- a/platform/darwin/src/MGLLineStyleLayer.mm
+++ b/platform/darwin/src/MGLLineStyleLayer.mm
@@ -1,6 +1,7 @@
 // This file is generated. 
 // Edit platform/darwin/scripts/generate-style-code.js, then run `make style-code-darwin`.
 
+#import "MGLSource.h"
 #import "NSPredicate+MGLAdditions.h"
 #import "MGLStyleLayer_Private.h"
 #import "MGLStyleAttributeValue.h"
@@ -13,6 +14,7 @@
 @property (nonatomic) mbgl::style::LineLayer *layer;
 @property (nonatomic, readwrite) NSString *layerIdentifier;
 @property (nonatomic, readwrite) NSString *sourceIdentifier;
+@property (nonatomic, readwrite) NSString *sourceLayerIdentifier;
 
 @end
 
@@ -20,11 +22,24 @@
 
 @synthesize mapView;
 
-- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier sourceIdentifier:(NSString *)sourceIdentifier {
+
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source
+{
+    if (self = [super init]) {
+        _layerIdentifier = layerIdentifier;
+        _sourceIdentifier = source.sourceIdentifier;
+        _layer = new mbgl::style::LineLayer(layerIdentifier.UTF8String, source.sourceIdentifier.UTF8String);
+    }
+    return self;
+}
+
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source sourceLayer:(NSString *)sourceLayer
+{
     if (self = [super init]) {
         _layerIdentifier = layerIdentifier;
-        _sourceIdentifier = sourceIdentifier;
-        _layer = new mbgl::style::LineLayer(layerIdentifier.UTF8String, sourceIdentifier.UTF8String);
+        _sourceIdentifier = source.sourceIdentifier;
+        _layer = new mbgl::style::LineLayer(layerIdentifier.UTF8String, source.sourceIdentifier.UTF8String);
+        _layer->setSourceLayer(sourceLayer.UTF8String);
     }
     return self;
 }
diff --git a/platform/darwin/src/MGLRasterStyleLayer.h b/platform/darwin/src/MGLRasterStyleLayer.h
index 213619be04..b7f2cd7fda 100644
--- a/platform/darwin/src/MGLRasterStyleLayer.h
+++ b/platform/darwin/src/MGLRasterStyleLayer.h
@@ -8,6 +8,10 @@ NS_ASSUME_NONNULL_BEGIN
 
 @interface MGLRasterStyleLayer : MGLBaseStyleLayer <MGLStyleLayer>
 
+
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source;
+
+
 #pragma mark - Accessing the Paint Attributes
 
 /**
diff --git a/platform/darwin/src/MGLRasterStyleLayer.mm b/platform/darwin/src/MGLRasterStyleLayer.mm
index dc70dfbde7..74cffc2ed2 100644
--- a/platform/darwin/src/MGLRasterStyleLayer.mm
+++ b/platform/darwin/src/MGLRasterStyleLayer.mm
@@ -1,6 +1,7 @@
 // This file is generated. 
 // Edit platform/darwin/scripts/generate-style-code.js, then run `make style-code-darwin`.
 
+#import "MGLSource.h"
 #import "NSPredicate+MGLAdditions.h"
 #import "MGLStyleLayer_Private.h"
 #import "MGLStyleAttributeValue.h"
@@ -13,6 +14,7 @@
 @property (nonatomic) mbgl::style::RasterLayer *layer;
 @property (nonatomic, readwrite) NSString *layerIdentifier;
 @property (nonatomic, readwrite) NSString *sourceIdentifier;
+@property (nonatomic, readwrite) NSString *sourceLayerIdentifier;
 
 @end
 
@@ -20,15 +22,18 @@
 
 @synthesize mapView;
 
-- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier sourceIdentifier:(NSString *)sourceIdentifier {
+
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source
+{
     if (self = [super init]) {
         _layerIdentifier = layerIdentifier;
-        _sourceIdentifier = sourceIdentifier;
-        _layer = new mbgl::style::RasterLayer(layerIdentifier.UTF8String, sourceIdentifier.UTF8String);
+        _sourceIdentifier = source.sourceIdentifier;
+        _layer = new mbgl::style::RasterLayer(layerIdentifier.UTF8String, source.sourceIdentifier.UTF8String);
     }
     return self;
 }
 
+
 #pragma mark - Accessing the Paint Attributes
 
 - (void)setRasterOpacity:(id <MGLStyleAttributeValue, MGLStyleAttributeValue_Private>)rasterOpacity {
diff --git a/platform/darwin/src/MGLRuntimeStylingTests.m.ejs b/platform/darwin/src/MGLRuntimeStylingTests.m.ejs
index 9a3e59b7b6..0d0317cb65 100644
--- a/platform/darwin/src/MGLRuntimeStylingTests.m.ejs
+++ b/platform/darwin/src/MGLRuntimeStylingTests.m.ejs
@@ -17,7 +17,7 @@
     NSString *filePath = [[NSBundle bundleForClass:self.class] pathForResource:@"amsterdam" ofType:@"geojson"];
     NSURL *url = [NSURL fileURLWithPath:filePath];
     MGLGeoJSONSource *source = [[MGLGeoJSONSource alloc] initWithSourceIdentifier:@"sourceID" URL:url];
-    MGL<%- camelize(type) %>StyleLayer *layer = [[MGL<%- camelize(type) %>StyleLayer alloc] initWithLayerIdentifier:@"layerID" sourceIdentifier:@"sourceID"];
+MGL<%- camelize(type) %>StyleLayer *layer = [[MGL<%- camelize(type) %>StyleLayer alloc] initWithLayerIdentifier:@"layerID" source:source];
     [self.mapView.style addSource:source];
     [self.mapView.style addLayer:layer];
 
diff --git a/platform/darwin/src/MGLStyleLayer.h b/platform/darwin/src/MGLStyleLayer.h
index 30456331db..d4ed525a3f 100644
--- a/platform/darwin/src/MGLStyleLayer.h
+++ b/platform/darwin/src/MGLStyleLayer.h
@@ -6,12 +6,7 @@
 
 @property (nonatomic, weak) MGLMapView *mapView;
 @property (nonatomic, copy, readonly) NSString *layerIdentifier;
-
-@optional
-
 @property (nonatomic, readonly) NSString *sourceIdentifier;
-
-- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier;
-- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier sourceIdentifier:(NSString *)sourceIdentifier;
+@property (nonatomic, readonly) NSString *sourceLayerIdentifier;
 
 @end
diff --git a/platform/darwin/src/MGLStyleLayer.h.ejs b/platform/darwin/src/MGLStyleLayer.h.ejs
index 8acda024c4..64a7e06b5f 100644
--- a/platform/darwin/src/MGLStyleLayer.h.ejs
+++ b/platform/darwin/src/MGLStyleLayer.h.ejs
@@ -35,6 +35,16 @@ typedef NS_ENUM(NSUInteger, MGL<%- camelize(type) %>StyleLayer<%- camelize(prope
 <% } -%>
 @interface MGL<%- camelize(type) %>StyleLayer : MGLBaseStyleLayer <MGLStyleLayer>
 
+<% if (type == 'background') { -%>
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier;
+<% } -%>
+
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source;
+
+<% if (type !== 'background' && type !== 'raster') { -%>
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source sourceLayer:(NSString *)sourceLayer;
+<% } -%>
+
 <% if (type !== 'background' && type !== 'raster') { -%>
 /**
  A predicate that corresponds to the layer's <a href='https://www.mapbox.com/mapbox-gl-style-spec/#types-filter'>filter</a>.
diff --git a/platform/darwin/src/MGLStyleLayer.mm.ejs b/platform/darwin/src/MGLStyleLayer.mm.ejs
index 4615aeeb9b..233117fa91 100644
--- a/platform/darwin/src/MGLStyleLayer.mm.ejs
+++ b/platform/darwin/src/MGLStyleLayer.mm.ejs
@@ -6,6 +6,7 @@
 // This file is generated. 
 // Edit platform/darwin/scripts/generate-style-code.js, then run `make style-code-darwin`.
 
+#import "MGLSource.h"
 #import "NSPredicate+MGLAdditions.h"
 #import "MGLStyleLayer_Private.h"
 #import "MGLStyleAttributeValue.h"
@@ -18,6 +19,7 @@
 @property (nonatomic) mbgl::style::<%- camelize(type) %>Layer *layer;
 @property (nonatomic, readwrite) NSString *layerIdentifier;
 @property (nonatomic, readwrite) NSString *sourceIdentifier;
+@property (nonatomic, readwrite) NSString *sourceLayerIdentifier;
 
 @end
 
@@ -25,16 +27,41 @@
 
 @synthesize mapView;
 
-- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier sourceIdentifier:(NSString *)sourceIdentifier {
+<% if (type == 'background') { -%>
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier
+{
+    if (self = [super init]) {
+        _layerIdentifier = layerIdentifier;
+        <%- initLayerIdentifierOnly(type) %>
+    }
+    return self;
+}
+<% } -%>
+
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source
+{
     if (self = [super init]) {
         _layerIdentifier = layerIdentifier;
-        _sourceIdentifier = sourceIdentifier;
+        _sourceIdentifier = source.sourceIdentifier;
         <%- initLayer(type) %>
     }
     return self;
 }
 
 <% if (type !== 'background' && type !== 'raster') { -%>
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source sourceLayer:(NSString *)sourceLayer
+{
+    if (self = [super init]) {
+        _layerIdentifier = layerIdentifier;
+        _sourceIdentifier = source.sourceIdentifier;
+        <%- initLayerWithSourceLayer(type) %>
+        <%- setSourceLayer() %>
+    }
+    return self;
+}
+<% } -%>
+
+<% if (type !== 'background' && type !== 'raster') { -%>
 - (void)setPredicate:(NSPredicate *)predicate
 {
     self.layer->setFilter(predicate.mgl_filter);
diff --git a/platform/darwin/src/MGLSymbolStyleLayer.h b/platform/darwin/src/MGLSymbolStyleLayer.h
index eacd158dda..c900518b9b 100644
--- a/platform/darwin/src/MGLSymbolStyleLayer.h
+++ b/platform/darwin/src/MGLSymbolStyleLayer.h
@@ -69,6 +69,11 @@ typedef NS_ENUM(NSUInteger, MGLSymbolStyleLayerTextTranslateAnchor) {
 
 @interface MGLSymbolStyleLayer : MGLBaseStyleLayer <MGLStyleLayer>
 
+
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source;
+
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source sourceLayer:(NSString *)sourceLayer;
+
 /**
  A predicate that corresponds to the layer's <a href='https://www.mapbox.com/mapbox-gl-style-spec/#types-filter'>filter</a>.
  
diff --git a/platform/darwin/src/MGLSymbolStyleLayer.mm b/platform/darwin/src/MGLSymbolStyleLayer.mm
index 1fb3a0a587..4d9b20fbcb 100644
--- a/platform/darwin/src/MGLSymbolStyleLayer.mm
+++ b/platform/darwin/src/MGLSymbolStyleLayer.mm
@@ -1,6 +1,7 @@
 // This file is generated. 
 // Edit platform/darwin/scripts/generate-style-code.js, then run `make style-code-darwin`.
 
+#import "MGLSource.h"
 #import "NSPredicate+MGLAdditions.h"
 #import "MGLStyleLayer_Private.h"
 #import "MGLStyleAttributeValue.h"
@@ -13,6 +14,7 @@
 @property (nonatomic) mbgl::style::SymbolLayer *layer;
 @property (nonatomic, readwrite) NSString *layerIdentifier;
 @property (nonatomic, readwrite) NSString *sourceIdentifier;
+@property (nonatomic, readwrite) NSString *sourceLayerIdentifier;
 
 @end
 
@@ -20,11 +22,24 @@
 
 @synthesize mapView;
 
-- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier sourceIdentifier:(NSString *)sourceIdentifier {
+
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source
+{
+    if (self = [super init]) {
+        _layerIdentifier = layerIdentifier;
+        _sourceIdentifier = source.sourceIdentifier;
+        _layer = new mbgl::style::SymbolLayer(layerIdentifier.UTF8String, source.sourceIdentifier.UTF8String);
+    }
+    return self;
+}
+
+- (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source sourceLayer:(NSString *)sourceLayer
+{
     if (self = [super init]) {
         _layerIdentifier = layerIdentifier;
-        _sourceIdentifier = sourceIdentifier;
-        _layer = new mbgl::style::SymbolLayer(layerIdentifier.UTF8String, sourceIdentifier.UTF8String);
+        _sourceIdentifier = source.sourceIdentifier;
+        _layer = new mbgl::style::SymbolLayer(layerIdentifier.UTF8String, source.sourceIdentifier.UTF8String);
+        _layer->setSourceLayer(sourceLayer.UTF8String);
     }
     return self;
 }
diff --git a/platform/darwin/test/MGLBackgroundStyleLayerTests.m b/platform/darwin/test/MGLBackgroundStyleLayerTests.m
index 21d6a8832f..f4fdae61a4 100644
--- a/platform/darwin/test/MGLBackgroundStyleLayerTests.m
+++ b/platform/darwin/test/MGLBackgroundStyleLayerTests.m
@@ -12,7 +12,7 @@
     NSString *filePath = [[NSBundle bundleForClass:self.class] pathForResource:@"amsterdam" ofType:@"geojson"];
     NSURL *url = [NSURL fileURLWithPath:filePath];
     MGLGeoJSONSource *source = [[MGLGeoJSONSource alloc] initWithSourceIdentifier:@"sourceID" URL:url];
-    MGLBackgroundStyleLayer *layer = [[MGLBackgroundStyleLayer alloc] initWithLayerIdentifier:@"layerID" sourceIdentifier:@"sourceID"];
+MGLBackgroundStyleLayer *layer = [[MGLBackgroundStyleLayer alloc] initWithLayerIdentifier:@"layerID" source:source];
     [self.mapView.style addSource:source];
     [self.mapView.style addLayer:layer];
 
diff --git a/platform/darwin/test/MGLCircleStyleLayerTests.m b/platform/darwin/test/MGLCircleStyleLayerTests.m
index de0ebe81d8..0e70c3f836 100644
--- a/platform/darwin/test/MGLCircleStyleLayerTests.m
+++ b/platform/darwin/test/MGLCircleStyleLayerTests.m
@@ -12,7 +12,7 @@
     NSString *filePath = [[NSBundle bundleForClass:self.class] pathForResource:@"amsterdam" ofType:@"geojson"];
     NSURL *url = [NSURL fileURLWithPath:filePath];
     MGLGeoJSONSource *source = [[MGLGeoJSONSource alloc] initWithSourceIdentifier:@"sourceID" URL:url];
-    MGLCircleStyleLayer *layer = [[MGLCircleStyleLayer alloc] initWithLayerIdentifier:@"layerID" sourceIdentifier:@"sourceID"];
+MGLCircleStyleLayer *layer = [[MGLCircleStyleLayer alloc] initWithLayerIdentifier:@"layerID" source:source];
     [self.mapView.style addSource:source];
     [self.mapView.style addLayer:layer];
 
diff --git a/platform/darwin/test/MGLFillStyleLayerTests.m b/platform/darwin/test/MGLFillStyleLayerTests.m
index e926ef6335..7994d76517 100644
--- a/platform/darwin/test/MGLFillStyleLayerTests.m
+++ b/platform/darwin/test/MGLFillStyleLayerTests.m
@@ -12,7 +12,7 @@
     NSString *filePath = [[NSBundle bundleForClass:self.class] pathForResource:@"amsterdam" ofType:@"geojson"];
     NSURL *url = [NSURL fileURLWithPath:filePath];
     MGLGeoJSONSource *source = [[MGLGeoJSONSource alloc] initWithSourceIdentifier:@"sourceID" URL:url];
-    MGLFillStyleLayer *layer = [[MGLFillStyleLayer alloc] initWithLayerIdentifier:@"layerID" sourceIdentifier:@"sourceID"];
+MGLFillStyleLayer *layer = [[MGLFillStyleLayer alloc] initWithLayerIdentifier:@"layerID" source:source];
     [self.mapView.style addSource:source];
     [self.mapView.style addLayer:layer];
 
diff --git a/platform/darwin/test/MGLFilterTests.mm b/platform/darwin/test/MGLFilterTests.mm
index 5b102e2e86..513963ab7e 100644
--- a/platform/darwin/test/MGLFilterTests.mm
+++ b/platform/darwin/test/MGLFilterTests.mm
@@ -19,7 +19,7 @@
     NSData *geoJSONData = [NSData dataWithContentsOfURL:url];
     source = [[MGLGeoJSONSource alloc] initWithSourceIdentifier:@"test-source" geoJSONData:geoJSONData];
     [self.mapView.style addSource:source];
-    layer = [[MGLLineStyleLayer alloc] initWithLayerIdentifier:@"test-layer" sourceIdentifier:@"test-source"];
+    layer = [[MGLLineStyleLayer alloc] initWithLayerIdentifier:@"test-layer" source:source];
 }
 
 - (void)tearDown
diff --git a/platform/darwin/test/MGLLineStyleLayerTests.m b/platform/darwin/test/MGLLineStyleLayerTests.m
index 859e010579..ff607f2e2b 100644
--- a/platform/darwin/test/MGLLineStyleLayerTests.m
+++ b/platform/darwin/test/MGLLineStyleLayerTests.m
@@ -12,7 +12,7 @@
     NSString *filePath = [[NSBundle bundleForClass:self.class] pathForResource:@"amsterdam" ofType:@"geojson"];
     NSURL *url = [NSURL fileURLWithPath:filePath];
     MGLGeoJSONSource *source = [[MGLGeoJSONSource alloc] initWithSourceIdentifier:@"sourceID" URL:url];
-    MGLLineStyleLayer *layer = [[MGLLineStyleLayer alloc] initWithLayerIdentifier:@"layerID" sourceIdentifier:@"sourceID"];
+MGLLineStyleLayer *layer = [[MGLLineStyleLayer alloc] initWithLayerIdentifier:@"layerID" source:source];
     [self.mapView.style addSource:source];
     [self.mapView.style addLayer:layer];
 
diff --git a/platform/darwin/test/MGLRasterStyleLayerTests.m b/platform/darwin/test/MGLRasterStyleLayerTests.m
index 75e900c4c6..7158c9aef2 100644
--- a/platform/darwin/test/MGLRasterStyleLayerTests.m
+++ b/platform/darwin/test/MGLRasterStyleLayerTests.m
@@ -12,7 +12,7 @@
     NSString *filePath = [[NSBundle bundleForClass:self.class] pathForResource:@"amsterdam" ofType:@"geojson"];
     NSURL *url = [NSURL fileURLWithPath:filePath];
     MGLGeoJSONSource *source = [[MGLGeoJSONSource alloc] initWithSourceIdentifier:@"sourceID" URL:url];
-    MGLRasterStyleLayer *layer = [[MGLRasterStyleLayer alloc] initWithLayerIdentifier:@"layerID" sourceIdentifier:@"sourceID"];
+MGLRasterStyleLayer *layer = [[MGLRasterStyleLayer alloc] initWithLayerIdentifier:@"layerID" source:source];
     [self.mapView.style addSource:source];
     [self.mapView.style addLayer:layer];
 
diff --git a/platform/darwin/test/MGLSymbolStyleLayerTests.m b/platform/darwin/test/MGLSymbolStyleLayerTests.m
index a32af96828..dbd8f50482 100644
--- a/platform/darwin/test/MGLSymbolStyleLayerTests.m
+++ b/platform/darwin/test/MGLSymbolStyleLayerTests.m
@@ -12,7 +12,7 @@
     NSString *filePath = [[NSBundle bundleForClass:self.class] pathForResource:@"amsterdam" ofType:@"geojson"];
     NSURL *url = [NSURL fileURLWithPath:filePath];
     MGLGeoJSONSource *source = [[MGLGeoJSONSource alloc] initWithSourceIdentifier:@"sourceID" URL:url];
-    MGLSymbolStyleLayer *layer = [[MGLSymbolStyleLayer alloc] initWithLayerIdentifier:@"layerID" sourceIdentifier:@"sourceID"];
+MGLSymbolStyleLayer *layer = [[MGLSymbolStyleLayer alloc] initWithLayerIdentifier:@"layerID" source:source];
     [self.mapView.style addSource:source];
     [self.mapView.style addLayer:layer];
 
diff --git a/platform/ios/app/MBXViewController.m b/platform/ios/app/MBXViewController.m
index 605d6b2da8..0f81643f73 100644
--- a/platform/ios/app/MBXViewController.m
+++ b/platform/ios/app/MBXViewController.m
@@ -484,7 +484,7 @@ static NSString * const MBXViewControllerAnnotationViewReuseIdentifer = @"MBXVie
     MGLGeoJSONSource *source = [[MGLGeoJSONSource alloc] initWithSourceIdentifier:@"ams" URL:geoJSONURL];
     [self.mapView.style addSource:source];
     
-    MGLFillStyleLayer *fillLayer = [[MGLFillStyleLayer alloc] initWithLayerIdentifier:@"test" sourceIdentifier:@"ams"];
+    MGLFillStyleLayer *fillLayer = [[MGLFillStyleLayer alloc] initWithLayerIdentifier:@"test" source:source];
     fillLayer.fillColor = [UIColor purpleColor];
     [self.mapView.style addLayer:fillLayer];
 }
@@ -495,7 +495,7 @@ static NSString * const MBXViewControllerAnnotationViewReuseIdentifer = @"MBXVie
     MGLRasterSource *rasterSource = [[MGLRasterSource alloc] initWithSourceIdentifier:@"my-raster-source" URL:rasterURL tileSize:512];
     [self.mapView.style addSource:rasterSource];
     
-    MGLRasterStyleLayer *rasterLayer = [[MGLRasterStyleLayer alloc] initWithLayerIdentifier:@"my-raster-layer" sourceIdentifier:@"my-raster-source"];
+    MGLRasterStyleLayer *rasterLayer = [[MGLRasterStyleLayer alloc] initWithLayerIdentifier:@"my-raster-layer" source:rasterSource];
     MGLStyleAttributeFunction *opacityFunction = [[MGLStyleAttributeFunction alloc] init];
     opacityFunction.stops = @{@20.0f: @1.0f,
                               @5.0f: @0.0f};
diff --git a/platform/macos/app/MapDocument.m b/platform/macos/app/MapDocument.m
index 8d24b35b6a..42398ff0a6 100644
--- a/platform/macos/app/MapDocument.m
+++ b/platform/macos/app/MapDocument.m
@@ -507,7 +507,7 @@ NS_ARRAY_OF(id <MGLAnnotation>) *MBXFlattenedShapes(NS_ARRAY_OF(id <MGLAnnotatio
     MGLGeoJSONSource *source = [[MGLGeoJSONSource alloc] initWithSourceIdentifier:@"ams" URL:geoJSONURL];
     [self.mapView.style addSource:source];
     
-    MGLFillStyleLayer *fillLayer = [[MGLFillStyleLayer alloc] initWithLayerIdentifier:@"test" sourceIdentifier:@"ams"];
+    MGLFillStyleLayer *fillLayer = [[MGLFillStyleLayer alloc] initWithLayerIdentifier:@"test" source:source];
     fillLayer.fillColor = [NSColor greenColor];
     fillLayer.predicate = [NSPredicate predicateWithFormat:@"%K == %@", @"type", @"park"];
     [self.mapView.style addLayer:fillLayer];