Refactor the iOS app template to move setups to a helper class

Summary:
Changelog: [internal] Move initital setups in AppDelegate to util classes.

This will make it easy to apply the new architecture changes in the future.

Reviewed By: cortinico

Differential Revision: D33051517

fbshipit-source-id: 16e326b7816fae83df65450c545e7dce1a93b9d0

Author: sota000

React-Core.podspec

@@ -47,7 +47,7 @@ Pod::Spec.new do |s|
   s.compiler_flags         = folly_compiler_flags + ' ' + boost_compiler_flags
   s.header_dir             = "React"
   s.framework              = "JavaScriptCore"
-  s.pod_target_xcconfig    = { "HEADER_SEARCH_PATHS" => "\"$(PODS_TARGET_SRCROOT)/ReactCommon\" \"$(PODS_ROOT)/boost\" \"$(PODS_ROOT)/DoubleConversion\" \"$(PODS_ROOT)/RCT-Folly\" \"${PODS_ROOT}/Headers/Public/React-hermes\" \"${PODS_ROOT}/Headers/Public/hermes-engine\"", "DEFINES_MODULE" => "YES" }
+  s.pod_target_xcconfig    = { "HEADER_SEARCH_PATHS" => "\"$(PODS_TARGET_SRCROOT)/ReactCommon\" \"$(PODS_ROOT)/boost\" \"$(PODS_ROOT)/DoubleConversion\" \"$(PODS_ROOT)/RCT-Folly\" \"${PODS_ROOT}/Headers/Public/React-hermes\" \"${PODS_ROOT}/Headers/Public/hermes-engine\" \"${PODS_ROOT}/Headers/Public/FlipperKit\"", "DEFINES_MODULE" => "YES" }
   s.user_target_xcconfig   = { "HEADER_SEARCH_PATHS" => "\"$(PODS_ROOT)/Headers/Private/React-Core\""}
   s.default_subspec        = "Default"
 

React/AppSetup/RCTAppSetupUtils.h

@@ -0,0 +1,17 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#import <Foundation/Foundation.h>
+#import <React/RCTBridge.h>
+#import <React/RCTRootView.h>
+
+@interface RCTAppSetupUtils : NSObject
++ (void)prepareApp:(UIApplication *_Nonnull)application;
++ (RCTRootView *_Nonnull)defaultRootViewWithBridge:(RCTBridge *_Nonnull)bridge
+                                        moduleName:(NSString *_Nonnull)moduleName
+                                 initialProperties:(nullable NSDictionary *)initialProperties;
+@end

React/AppSetup/RCTAppSetupUtils.mm

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#import "RCTAppSetupUtils.h"
+
+#ifdef FB_SONARKIT_ENABLED
+#import <FlipperKit/FlipperClient.h>
+#import <FlipperKitLayoutPlugin/FlipperKitLayoutPlugin.h>
+#import <FlipperKitNetworkPlugin/FlipperKitNetworkPlugin.h>
+#import <FlipperKitReactPlugin/FlipperKitReactPlugin.h>
+#import <FlipperKitUserDefaultsPlugin/FKUserDefaultsPlugin.h>
+#import <SKIOSNetworkPlugin/SKIOSNetworkAdapter.h>
+
+static void InitializeFlipper(UIApplication *application)
+{
+  FlipperClient *client = [FlipperClient sharedClient];
+  SKDescriptorMapper *layoutDescriptorMapper = [[SKDescriptorMapper alloc] initWithDefaults];
+  [client addPlugin:[[FlipperKitLayoutPlugin alloc] initWithRootNode:application
+                                                withDescriptorMapper:layoutDescriptorMapper]];
+  [client addPlugin:[[FKUserDefaultsPlugin alloc] initWithSuiteName:nil]];
+  [client addPlugin:[FlipperKitReactPlugin new]];
+  [client addPlugin:[[FlipperKitNetworkPlugin alloc] initWithNetworkAdapter:[SKIOSNetworkAdapter new]]];
+  [client start];
+}
+#endif
+
+@implementation RCTAppSetupUtils
+
++ (void)prepareApp:(UIApplication *)application
+{
+#ifdef FB_SONARKIT_ENABLED
+  InitializeFlipper(application);
+#endif
+}
+
++ (RCTRootView *)defaultRootViewWithBridge:(RCTBridge *)bridge
+                                moduleName:(NSString *)moduleName
+                         initialProperties:(NSDictionary *)initialProperties
+{
+  return [[RCTRootView alloc] initWithBridge:bridge moduleName:moduleName initialProperties:initialProperties];
+}
+
+@end

template/ios/HelloWorld/AppDelegate.mm

@@ -4,37 +4,18 @@
 #import <React/RCTBundleURLProvider.h>
 #import <React/RCTRootView.h>
 
-#ifdef FB_SONARKIT_ENABLED
-#import <FlipperKit/FlipperClient.h>
-#import <FlipperKitLayoutPlugin/FlipperKitLayoutPlugin.h>
-#import <FlipperKitUserDefaultsPlugin/FKUserDefaultsPlugin.h>
-#import <FlipperKitNetworkPlugin/FlipperKitNetworkPlugin.h>
-#import <SKIOSNetworkPlugin/SKIOSNetworkAdapter.h>
-#import <FlipperKitReactPlugin/FlipperKitReactPlugin.h>
-
-static void InitializeFlipper(UIApplication *application) {
-  FlipperClient *client = [FlipperClient sharedClient];
-  SKDescriptorMapper *layoutDescriptorMapper = [[SKDescriptorMapper alloc] initWithDefaults];
-  [client addPlugin:[[FlipperKitLayoutPlugin alloc] initWithRootNode:application withDescriptorMapper:layoutDescriptorMapper]];
-  [client addPlugin:[[FKUserDefaultsPlugin alloc] initWithSuiteName:nil]];
-  [client addPlugin:[FlipperKitReactPlugin new]];
-  [client addPlugin:[[FlipperKitNetworkPlugin alloc] initWithNetworkAdapter:[SKIOSNetworkAdapter new]]];
-  [client start];
-}
-#endif
+#import <React/RCTAppSetupUtils.h>
 
 @implementation AppDelegate
 
 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
 {
-#ifdef FB_SONARKIT_ENABLED
-  InitializeFlipper(application);
-#endif
+  [RCTAppSetupUtils prepareApp: application];
 
   RCTBridge *bridge = [[RCTBridge alloc] initWithDelegate:self launchOptions:launchOptions];
-  RCTRootView *rootView = [[RCTRootView alloc] initWithBridge:bridge
-                                                   moduleName:@"HelloWorld"
-                                            initialProperties:nil];
+  RCTRootView *rootView = [RCTAppSetupUtils defaultRootViewWithBridge:bridge
+                                   moduleName:@"HelloWorld"
+                           initialProperties:nil];
 
   if (@available(iOS 13.0, *)) {
       rootView.backgroundColor = [UIColor systemBackgroundColor];