push/pop Coordinator context.

Author: Alex Usbergo

Demo/CoreRenderDemo/ContentView.swift

@@ -21,9 +21,8 @@ struct ContentView: View {
             .font(UIFont.boldSystemFont(ofSize: 14))
             .padding(8)
         }
-          .alignItems(.center)
+          .alignItems(.flexEnd)
           .background(UIColor.systemGroupedBackground)
-          .matchHostingViewWidth(withMargin: 0)
       }
     }
   }
@@ -32,5 +31,7 @@ struct ContentView: View {
 struct ContentView_Previews: PreviewProvider {
   static var previews: some View {
     ContentView()
+      .previewLayout(.fixed(width: 320, height: 240))
+
   }
 }

Sources/CoreRender/CRContext.h

@@ -45,6 +45,14 @@ NS_SWIFT_NAME(Context)
 
 /// Remove the object as delegate (if necessary).
 - (void)removeDelegate:(id<CRContextDelegate>)delegate;
+/// Make a new context-aware coordinator key.
+- (NSString *)makeCoordinatorKey:(NSString *)key;
+/// Tell the context that we're in the scope of the given coordinator.
+/// @note: This ensure that two different coordinators with the same key in two diferent
+/// locations in the hierarchy could exist.
+- (void)pushCoordinatorContext:(NSString *)key;
+/// Pop the current coordinato context.
+- (void)popCoordinatorContext;
 
 @end
 

Sources/CoreRender/CRContext.mm

@@ -30,12 +30,14 @@ @implementation CRContext {
   NSMutableDictionary<NSString *, NSMutableDictionary<NSString *, CRCoordinator *> *>
       *_coordinators;
   NSPointerArray *_delegates;
+  NSMutableArray *_coordinatorPath;
 }
 
 - (instancetype)init {
   if (self = [super init]) {
     _coordinators = @{}.mutableCopy;
     _delegates = [NSPointerArray weakObjectsPointerArray];
+    _coordinatorPath = @[].mutableCopy;
   }
   return self;
 }
@@ -82,4 +84,19 @@ - (void)removeDelegate:(id<CRContextDelegate>)delegate {
   if (removeIdx != NSNotFound) [_delegates removePointerAtIndex:removeIdx];
 }
 
+- (NSString *)makeCoordinatorKey:(NSString *)key {
+  return
+      [NSString stringWithFormat:@"%@/%@", [_coordinatorPath componentsJoinedByString:@"/"], key];
+}
+
+- (void)pushCoordinatorContext:(NSString *)key {
+  CR_ASSERT_ON_MAIN_THREAD();
+  [_coordinatorPath addObject:key];
+}
+
+- (void)popCoordinatorContext {
+  CR_ASSERT_ON_MAIN_THREAD();
+  [_coordinatorPath removeLastObject];
+}
+
 @end

Sources/CoreRender/CRNode.h

@@ -44,7 +44,7 @@ NS_SWIFT_NAME(ConcreteNode)
 /// A custom *reuseIdentifier* is mandatory if the node has a custom creation closure.
 @property(nonatomic, readonly) NSString *reuseIdentifier;
 /// A unique key for the component/node (necessary if the associated coordinator is stateful).
-@property(nonatomic, readonly, nullable) NSString *key;
+@property(nonatomic, readonly, nullable) NSString *coordinatorKey;
 /// This component is the n-th children.
 @property(nonatomic, readonly) NSUInteger index;
 /// The subnodes of this node.

Sources/CoreRender/CRNode.mm

@@ -47,7 +47,7 @@ - (instancetype)initWithType:(Class)type
                   layoutSpec:(void (^)(CRNodeLayoutSpec<UIView *> *))layoutSpec {
   if (self = [super init]) {
     _reuseIdentifier = CR_NIL_COALESCING(reuseIdentifier, NSStringFromClass(type));
-    _key = key;
+    _coordinatorKey = key;
     _viewType = type;
     _mutableChildren = [[NSMutableArray alloc] init];
     self.viewInit = viewInit;
@@ -156,7 +156,7 @@ - (instancetype)bindCoordinator:(CRCoordinatorDescriptor *)descriptor {
 #pragma mark - Querying
 
 - (UIView *)viewWithKey:(NSString *)key {
-  if ([_key isEqualToString:key]) return _renderedView;
+  if ([_coordinatorKey isEqualToString:key]) return _renderedView;
   CR_FOREACH(child, _mutableChildren) {
     if (const auto view = [child viewWithKey:key]) return view;
   }
@@ -171,7 +171,7 @@ - (UIView *)viewWithKey:(NSString *)key {
 
 - (void)_viewsWithReuseIdentifier:(NSString *)reuseIdentifier
                         withArray:(NSMutableArray<UIView *> *)array {
-  if ([_key isEqualToString:reuseIdentifier] && _renderedView) {
+  if ([_coordinatorKey isEqualToString:reuseIdentifier] && _renderedView) {
     [array addObject:_renderedView];
   }
   CR_FOREACH(child, _mutableChildren) {

Sources/CoreRender/CRNodeBuilder.h

@@ -11,12 +11,14 @@ NS_SWIFT_NAME(OpaqueNodeBuilder)
 /// @note: This is required if the node has a custom @c viewInit.
 - (instancetype)withReuseIdentifier:(NSString *)reuseIdentifier;
 /// Unique node key (required for stateful components).
-/// @note: This is required if @c coordinatorType or @c state is set.
-- (instancetype)withKey:(NSString *)key;
+/// @note: Internal only - Use the @c Component class to bind a node to a coordinator.
+- (instancetype)_withCoordinatorKey:(NSString *)key;
 /// The coordinator assigned to this node.
-- (instancetype)withCoordinator:(CRCoordinator *)coordinator;
+/// @note: Internal only - Use the @c Component class to bind a node to a coordinator.
+- (instancetype)_withCoordinator:(CRCoordinator *)coordinator;
 /// The coordinator type assigned to this node.
-- (instancetype)withCoordinatorDescriptor:(CRCoordinatorDescriptor *)descriptor;
+/// @note: Internal only - Use the @c Component class to bind a node to a coordinator.
+- (instancetype)_withCoordinatorDescriptor:(CRCoordinatorDescriptor *)descriptor;
 /// Defines the node configuration and layout.
 - (instancetype)withLayoutSpec:(void (^)(CRNodeLayoutSpec<UIView *> *))layoutSpec;
 /// Build the concrete node.

Sources/CoreRender/CRNodeBuilder.mm

@@ -53,23 +53,23 @@ - (instancetype)withReuseIdentifier:(NSString *)reuseIdentifier {
   return self;
 }
 
-- (instancetype)withKey:(NSString *)key {
+- (instancetype)_withCoordinatorKey:(NSString *)key {
   CR_ASSERT_ON_MAIN_THREAD();
   _key = key;
   return self;
 }
 
-- (instancetype)withCoordinatorDescriptor:(CRCoordinatorDescriptor *)descriptor {
+- (instancetype)_withCoordinatorDescriptor:(CRCoordinatorDescriptor *)descriptor {
   CR_ASSERT_ON_MAIN_THREAD();
   _coordinatorDescriptor = descriptor;
   return self;
 }
 
-- (instancetype)withCoordinator:(CRCoordinator *)coordinator {
+- (instancetype)_withCoordinator:(CRCoordinator *)coordinator {
   CR_ASSERT_ON_MAIN_THREAD();
   const auto descriptor =
       [[CRCoordinatorDescriptor alloc] initWithType:coordinator.class key:coordinator.key];
-  return [self withCoordinatorDescriptor:descriptor];
+  return [self _withCoordinatorDescriptor:descriptor];
 }
 
 - (instancetype)withViewInit:(UIView * (^)(NSString *))viewInit {
@@ -129,19 +129,19 @@ - (instancetype)withReuseIdentifier:(NSString *)reuseIdentifier {
   NSAssert(NO, @"Called on abstract super class.");
 }
 
-- (instancetype)withKey:(NSString *)key {
+- (instancetype)_withCoordinatorKey:(NSString *)key {
   NSAssert(NO, @"Called on abstract super class.");
 }
 
 - (instancetype)withLayoutSpec:(void (^)(CRNodeLayoutSpec<UIView *> *))layoutSpec {
   NSAssert(NO, @"Called on abstract super class.");
 }
 
-- (instancetype)withCoordinator:(CRCoordinator *)coordinator {
+- (instancetype)_withCoordinator:(CRCoordinator *)coordinator {
   NSAssert(NO, @"Called on abstract super class.");
 }
 
-- (instancetype)withCoordinatorDescriptor:(CRCoordinatorDescriptor *)descriptor {
+- (instancetype)_withCoordinatorDescriptor:(CRCoordinatorDescriptor *)descriptor {
   NSAssert(NO, @"Called on abstract super class.");
 }
 

Sources/Render/Bridge.swift

@@ -19,12 +19,16 @@ public struct Component<C: Coordinator>: OpaqueNodeBuilderConvertible {
 
   public init(
     context: Context,
-    key: String = NSStringFromClass(C.self),
+    key: String? = nil,
     props: [AnyProp] = [],
     body: @escaping (Context, C) -> OpaqueNodeBuilder
   ) {
+    var argKey: String! = key ?? NSStringFromClass(C.self)
+    if !argKey.contains("/") {
+      argKey = context.makeCoordinatorKey(argKey)
+    }
     self.context = context
-    self.key = key
+    self.key = argKey
     self.props = props
     self.body = body
   }
@@ -39,7 +43,7 @@ public struct Component<C: Coordinator>: OpaqueNodeBuilderConvertible {
 public func makeComponent<C: Coordinator>(
   type: C.Type,
   context: Context,
-  key: String = NSStringFromClass(C.self),
+  key: String,
   props: [AnyProp] = [],
   body: (Context, C) -> OpaqueNodeBuilder
 ) -> OpaqueNodeBuilder {
@@ -48,9 +52,12 @@ public func makeComponent<C: Coordinator>(
   for setter in props {
     setter.apply(coordinator: coordinator)
   }
-  return body(context, coordinator)
+  context.pushCoordinatorContext(key);
+  let result = body(context, coordinator)
     .withReuseIdentifier(reuseIdentifier)
-    .withCoordinator(coordinator)
+    ._(with: coordinator)
+  context.popCoordinatorContext()
+  return result;
 }
 
 // MARK: - OpaqueNodeBuilderConvertible

Sources/Render/CommonNodeTypes.swift

@@ -45,14 +45,13 @@ public func LabelNode(
 }
 
 public func ButtonNode(
-  key: String,
+  reuseIdentifier: String,
   target: Any? = nil,
   action: Selector = #selector(Coordinator.onTouchUp(inside:)),
   @ContentBuilder builder: () -> ChildrenBuilder = ChildrenBuilder.default
 ) -> NodeBuilder<UIButton> {
   Node(UIButton.self, builder: builder)
-    .withKey(key)
-    .withReuseIdentifier(key)
+    .withReuseIdentifier(reuseIdentifier)
     .withViewInit { button in
       let button = UIButton()
       button.addTarget(target, action: action, for: .touchUpInside)

Tests/RenderTests/BridgeTest.swift

@@ -1,6 +1,6 @@
 import XCTest
-import CoreRenderObjC
 import CoreRender
+import Render
 
 class FooCoordinator: Coordinator {
   var count: Int = 0
@@ -20,7 +20,7 @@ class CRSwiftInteropTests: XCTestCase {
         LabelNode(text: "Foor")
         LabelNode(text: "Bar")
         Component<FooCoordinator>(context: context) { _, _ in
-          ButtonNode(key: "Hi")
+          ButtonNode(reuseIdentifier: "Hi")
         }
       }
     }

format_objc.sh

@@ -10,6 +10,6 @@ format() {
 }
 
 echo "Running clang-format..."
-cd Sources/CoreRenderObjC && format;
+cd Sources/CoreRender && format;
 cd ../../;
-cd Tests/CoreRenderObjCTests && format;
+cd Tests/CoreRenderTests && format;