feat: introduce new method to RCTAppDelegate

packages/react-native/Libraries/AppDelegate/RCTAppDelegate.h

@@ -159,8 +159,11 @@ NS_ASSUME_NONNULL_BEGIN
 - (BOOL)bridgelessEnabled;
 
 /// Return the bundle URL for the main bundle.
-- (NSURL *)bundleURL;
+- (NSURL *__nullable)bundleURL;
+
+- (UIView *)viewWithModuleName:(NSString *)moduleName initialProperties:(NSDictionary*)initialProperties launchOptions:(NSDictionary*)launchOptions;
 
 @end
 
 NS_ASSUME_NONNULL_END
+

packages/react-native/Libraries/AppDelegate/RCTAppDelegate.mm

@@ -40,6 +40,7 @@
 #import <react/renderer/runtimescheduler/RuntimeSchedulerCallInvoker.h>
 #import <react/runtime/JSRuntimeFactory.h>
 
+
 static NSString *const kRNConcurrentRoot = @"concurrentRoot";
 
 @interface RCTAppDelegate () <
@@ -83,51 +84,16 @@ - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(
 {
   RCTSetNewArchEnabled([self newArchEnabled]);
   BOOL enableTM = self.turboModuleEnabled;
-  BOOL fabricEnabled = self.fabricEnabled;
-  BOOL enableBridgeless = self.bridgelessEnabled;
-
-  NSDictionary *initProps = updateInitialProps([self prepareInitialProps], fabricEnabled);
 
   RCTAppSetupPrepareApp(application, enableTM, *_reactNativeConfig);
-
-  UIView *rootView;
-  if (enableBridgeless) {
-    // Enable native view config interop only if both bridgeless mode and Fabric is enabled.
-    RCTSetUseNativeViewConfigsInBridgelessMode(fabricEnabled);
-
-    // Enable TurboModule interop by default in Bridgeless mode
-    RCTEnableTurboModuleInterop(YES);
-    RCTEnableTurboModuleInteropBridgeProxy(YES);
-
-    [self createReactHost];
-    [RCTComponentViewFactory currentComponentViewFactory].thirdPartyFabricComponentsProvider = self;
-    RCTFabricSurface *surface = [_reactHost createSurfaceWithModuleName:self.moduleName initialProperties:initProps];
-
-    RCTSurfaceHostingProxyRootView *surfaceHostingProxyRootView = [[RCTSurfaceHostingProxyRootView alloc]
-        initWithSurface:surface
-        sizeMeasureMode:RCTSurfaceSizeMeasureModeWidthExact | RCTSurfaceSizeMeasureModeHeightExact];
-
-    rootView = (RCTRootView *)surfaceHostingProxyRootView;
-  } else {
-    if (!self.bridge) {
-      self.bridge = [self createBridgeWithDelegate:self launchOptions:launchOptions];
-    }
-    if ([self newArchEnabled]) {
-      self.bridgeAdapter = [[RCTSurfacePresenterBridgeAdapter alloc] initWithBridge:self.bridge
-                                                                   contextContainer:_contextContainer];
-      self.bridge.surfacePresenter = self.bridgeAdapter.surfacePresenter;
-
-      [RCTComponentViewFactory currentComponentViewFactory].thirdPartyFabricComponentsProvider = self;
-    }
-    rootView = [self createRootViewWithBridge:self.bridge moduleName:self.moduleName initProps:initProps];
-  }
-
-  [self customizeRootView:(RCTRootView *)rootView];
+
 #if TARGET_OS_VISION
-  self.window = [[UIWindow alloc] initWithFrame:RCTForegroundWindow().bounds];
+    /// Bail out of UIWindow initializaiton to support multi-window scenarios in SwiftUI lifecycle.
+    return YES;
 #else
+  UIView* rootView = [self viewWithModuleName:self.moduleName initialProperties:[self prepareInitialProps] launchOptions:launchOptions];
+
   self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
-#endif
 
   UIViewController *rootViewController = [self createRootViewController];
   [self setRootView:rootView toRootViewController:rootViewController];
@@ -136,13 +102,59 @@ - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(
   [self.window makeKeyAndVisible];
 
   return YES;
+#endif
 }
 
 - (void)applicationDidEnterBackground:(UIApplication *)application
 {
   // Noop
 }
 
+- (UIView *)viewWithModuleName:(NSString *)moduleName initialProperties:(NSDictionary*)initialProperties launchOptions:(NSDictionary*)launchOptions {
+    BOOL fabricEnabled = self.fabricEnabled;
+    BOOL enableBridgeless = self.bridgelessEnabled;
+
+    NSDictionary *initProps = updateInitialProps(initialProperties, fabricEnabled);
+
+    UIView *rootView;
+    if (enableBridgeless) {
+      // Enable native view config interop only if both bridgeless mode and Fabric is enabled.
+      RCTSetUseNativeViewConfigsInBridgelessMode(self.fabricEnabled);
+
+      // Enable TurboModule interop by default in Bridgeless mode
+      RCTEnableTurboModuleInterop(YES);
+      RCTEnableTurboModuleInteropBridgeProxy(YES);
+
+      [self createReactHost];
+      [RCTComponentViewFactory currentComponentViewFactory].thirdPartyFabricComponentsProvider = self;
+      RCTFabricSurface *surface = [_reactHost createSurfaceWithModuleName:self.moduleName initialProperties:initProps];
+
+      RCTSurfaceHostingProxyRootView *surfaceHostingProxyRootView = [[RCTSurfaceHostingProxyRootView alloc]
+          initWithSurface:surface
+          sizeMeasureMode:RCTSurfaceSizeMeasureModeWidthExact | RCTSurfaceSizeMeasureModeHeightExact];
+
+      rootView = (RCTRootView *)surfaceHostingProxyRootView;
+    } else {
+      if (!self.bridge) {
+        self.bridge = [self createBridgeWithDelegate:self launchOptions:launchOptions];
+      }
+      if ([self newArchEnabled]) {
+        if (!self.bridgeAdapter) {
+          self.bridgeAdapter = [[RCTSurfacePresenterBridgeAdapter alloc] initWithBridge:self.bridge
+                                                                       contextContainer:_contextContainer];
+          self.bridge.surfacePresenter = self.bridgeAdapter.surfacePresenter;
+
+          [RCTComponentViewFactory currentComponentViewFactory].thirdPartyFabricComponentsProvider = self;
+        }
+      }
+      rootView = [self createRootViewWithBridge:self.bridge moduleName:moduleName initProps:initProps];
+    }
+
+    [self customizeRootView:(RCTRootView *)rootView];
+
+    return rootView;
+}
+
 - (NSURL *)sourceURLForBridge:(RCTBridge *)bridge
 {
   [NSException raise:@"RCTBridgeDelegate::sourceURLForBridge not implemented"

packages/react-native/Libraries/AppDelegate/RCTAppSetupUtils.h

@@ -21,7 +21,7 @@
 #elif __has_include(<reacthermes/HermesExecutorFactory.h>)
 #import <reacthermes/HermesExecutorFactory.h>
 #endif
-#else // USE_HERMES
+#elif __has_include(<React/JSCExecutorFactory.h>) // USE_HERMES
 #import <React/JSCExecutorFactory.h>
 #endif // USE_HERMES
 

packages/react-native/Libraries/AppDelegate/RCTReactViewController.h

@@ -0,0 +1,12 @@
+#import <React/RCTBridgeDelegate.h>
+#import <UIKit/UIKit.h>
+
+@interface RCTReactViewController : UIViewController
+
+@property (nonatomic, strong) NSString *_Nonnull moduleName;
+@property (nonatomic, strong) NSDictionary *_Nullable initialProps;
+
+- (instancetype _Nonnull)initWithModuleName:(NSString *_Nonnull)moduleName
+                                   initProps:(NSDictionary *_Nullable)initProps;
+
+@end

packages/react-native/Libraries/AppDelegate/RCTReactViewController.mm

@@ -0,0 +1,27 @@
+#import "RCTReactViewController.h"
+#import <React/RCTUtils.h>
+
+#import "RCTAppDelegate.h"
+
+@implementation RCTReactViewController
+
+- (instancetype)initWithModuleName:(NSString *)moduleName initProps:(NSDictionary *)initProps {
+    if (self = [super init]) {
+        _moduleName = moduleName;
+        _initialProps = initProps;
+    }
+    return self;
+}
+
+- (void)loadView {
+    id<UIApplicationDelegate> appDelegate = RCTSharedApplication().delegate;
+    if ([appDelegate respondsToSelector:@selector(viewWithModuleName:initialProperties:launchOptions:)]) {
+        RCTAppDelegate *delegate = (RCTAppDelegate *)appDelegate;
+        self.view = [delegate viewWithModuleName:_moduleName initialProperties:_initialProps launchOptions:@{}];
+    } else {
+        [NSException raise:@"UIApplicationDelegate:viewWithModuleName:initialProperties:launchOptions: not implemented"
+                    format:@"Make sure you subclass RCTAppDelegate"];
+    }
+}
+
+@end