Summary:
Recently, I've introduced `RCTReactNativeFactory` in this PR: https://github.com/facebook/react-native/issues/46298, which is a good successor for `RCTAppDelegate`.
### Why?
`RCTAppDelegate` introduced strong coupling between React Native and AppDelegate pattern. From iOS 13+ there is a newer equivalent (Scene Delegate) which is not possible to achieve with current architecture. The proposed solution involves migration to a `RCTReactNativeFactory` a class that encapsulates initialization logic of React Native.
This migration will make brownfield initialization easier by making it more flexible and simpler to integrate into already established apps.
### Deprecation plan
The plan I've discussed with cipolleschi involves:
- Deprecation of `RCTAppDelegate` in 0.79 (current main)
- Migration off `RCTAppDelegate` to SceneDelegate + `RCTReactNativeFactory` in 0.80
## Changelog:
[IOS] [DEPRECATED] - deprecate RCTAppDelegate
Pull Request resolved: https://github.com/facebook/react-native/pull/49078
Test Plan: Not needed
Reviewed By: cortinico
Differential Revision: D69061022
Pulled By: cipolleschi
fbshipit-source-id: b02a0ff3f26be9320da749f38c9cf083804f9f30
Summary:
This PR implements `RCTRootViewFactory` a utility class (suggested by cipolleschi) that returns proper RCTRootView based on the current environment state (new arch/old arch/bridgeless). This class aims to preserve background compatibility by implementing a configuration class forwarding necessary class to RCTAppDelegate.
### Brownfield use case
This PR leverages the `RCTRootViewFactory` in `RCTAppDelegate` for the default initialization of React Native (greenfield).
Here is an example of creating a Brownfield integration (without RCTAppDelegate) using this class (can be later added to docs):
1. Store reference to `rootViewFactory` and to `UIWindow`
`AppDelegate.h`:
```objc
interface AppDelegate : UIResponder <UIApplicationDelegate>
property(nonatomic, strong) UIWindow* window;
property(nonatomic, strong) RCTRootViewFactory* rootViewFactory;
end
```
2. Create an initial configuration using `RCTRootViewFactoryConfiguration` and initialize `RCTRootViewFactory` using it. Then you can use the factory to create a new `RCTRootView` without worrying about old arch/new arch/bridgeless.
`AppDelegate.mm`
```objc
implementation AppDelegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary<UIApplicationLaunchOptionsKey,id> *)launchOptions {
// Create configuration
RCTRootViewFactoryConfiguration *configuration = [[RCTRootViewFactoryConfiguration alloc] initWithBundleURL:self.bundleURL
newArchEnabled:self.fabricEnabled
turboModuleEnabled:self.turboModuleEnabled
bridgelessEnabled:self.bridgelessEnabled];
// Initialize RCTRootViewFactory
self.rootViewFactory = [[RCTRootViewFactory alloc] initWithConfiguration:configuration];
// Create main root view
UIView *rootView = [self.rootViewFactory viewWithModuleName:@"RNTesterApp" initialProperties:@{} launchOptions:launchOptions];
// Set main window as you prefer for your Brownfield integration.
self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
UIViewController *rootViewController = [UIViewController new];
rootViewController.view = rootView;
self.window.rootViewController = rootViewController;
[self.window makeKeyAndVisible];
// Later in the codebase you can initialize more rootView's using rootViewFactory.
return YES;
}
end
```
bypass-github-export-checks
## Changelog:
[INTERNAL] [ADDED] - Implement RCTRootViewFactory
Pull Request resolved: https://github.com/facebook/react-native/pull/42263
Test Plan: Check if root view is properly created on app initialization
Reviewed By: dmytrorykun
Differential Revision: D53179625
Pulled By: cipolleschi
fbshipit-source-id: 9bc850965ba30d84ad3e67d91dd888f0547c2136
Oskar Kwaśniewski
Lulu Wu