Extend Fabric iOS plugins to include Core components

Summary:
Changelog: [Internal]

Load components only if they are used. This way we avoid upfront cost associated with loading components that are not used.

Reviewed By: fkgozali

Differential Revision: D18504437

fbshipit-source-id: 815dd0799f87e254ce0b899ee52a9bec8da45451

React/Fabric/Mounting/ComponentViews/RCTFabricComponentsPlugins.h

@@ -0,0 +1,40 @@
+/**
+ * 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.
+ *
+ * @generated by an internal plugin build system
+ */
+
+#ifdef RN_DISABLE_OSS_PLUGIN_HEADER
+
+// FB Internal: FBRCTFabricComponentsPlugins.h is autogenerated by the build system.
+#import <React/FBRCTFabricComponentsPlugins.h>
+
+#else
+
+// OSS-compatibility layer
+
+#import <Foundation/Foundation.h>
+#import <React/RCTComponentViewProtocol.h>
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wreturn-type-c-linkage"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+Class<RCTComponentViewProtocol> RCTFabricComponentsProvider(const char *name);
+
+// Lookup functions
+Class<RCTComponentViewProtocol> RCTSafeAreaViewCls(void) __attribute__((used));
+
+#ifdef __cplusplus
+}
+#endif
+
+#pragma GCC diagnostic pop
+
+#endif // RN_DISABLE_OSS_PLUGIN_HEADER

React/Fabric/Mounting/ComponentViews/RCTFabricComponentsPlugins.mm

@@ -0,0 +1,32 @@
+/**
+ * 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.
+ *
+ * @generated by an internal plugin build system
+ */
+
+#ifndef RN_DISABLE_OSS_PLUGIN_HEADER
+
+// OSS-compatibility layer
+
+#import "RCTFabricComponentsPlugins.h"
+
+#import <string>
+#import <unordered_map>
+
+Class<RCTComponentViewProtocol> RCTFabricComponentsProvider(const char *name) {
+  static std::unordered_map<std::string, Class (*)(void)> sFabricComponentsClassMap = {
+    {"SafeAreaView", RCTSafeAreaViewCls},
+  };
+
+  auto p = sFabricComponentsClassMap.find(name);
+  if (p != sFabricComponentsClassMap.end()) {
+    auto classFunc = p->second;
+    return classFunc();
+  }
+  return nil;
+}
+
+#endif // RN_DISABLE_OSS_PLUGIN_HEADER

React/Fabric/Mounting/ComponentViews/SafeAreaView/RCTSafeAreaViewComponentView.mm

@@ -10,6 +10,7 @@
 #import <react/components/safeareaview/SafeAreaViewComponentDescriptor.h>
 #import <react/components/safeareaview/SafeAreaViewState.h>
 #import "RCTConversions.h"
+#import "RCTFabricComponentsPlugins.h"
 
 using namespace facebook::react;
 
@@ -65,3 +66,8 @@ using namespace facebook::react;
 }
 
 @end
+
+Class<RCTComponentViewProtocol> RCTSafeAreaViewCls(void)
+{
+  return RCTSafeAreaViewComponentView.class;
+}

React/Fabric/Mounting/RCTComponentViewFactory.mm

@@ -19,6 +19,7 @@
 #import "RCTARTSurfaceViewComponentView.h"
 #import "RCTActivityIndicatorViewComponentView.h"
 #import "RCTComponentViewClassDescriptor.h"
+#import "RCTFabricComponentsPlugins.h"
 #import "RCTImageComponentView.h"
 #import "RCTLegacyViewManagerInteropComponentView.h"
 #import "RCTModalHostViewComponentView.h"
@@ -26,7 +27,6 @@
 #import "RCTParagraphComponentView.h"
 #import "RCTPullToRefreshViewComponentView.h"
 #import "RCTRootComponentView.h"
-#import "RCTSafeAreaViewComponentView.h"
 #import "RCTScrollViewComponentView.h"
 #import "RCTSliderComponentView.h"
 #import "RCTSwitchComponentView.h"
@@ -60,7 +60,6 @@ using namespace facebook::react;
   [componentViewFactory registerComponentViewClass:[RCTUnimplementedNativeComponentView class]];
   [componentViewFactory registerComponentViewClass:[RCTModalHostViewComponentView class]];
   [componentViewFactory registerComponentViewClass:[RCTARTSurfaceViewComponentView class]];
-  [componentViewFactory registerComponentViewClass:[RCTSafeAreaViewComponentView class]];
 
   auto providerRegistry = &componentViewFactory->_providerRegistry;
 
@@ -74,9 +73,16 @@ using namespace facebook::react;
         [componentViewFactory registerComponentViewClass:klass];
         return;
       }
+    } else {
+      // Fallback 2: In case delegate isn't defined, look into core components.
+      Class<RCTComponentViewProtocol> klass = RCTFabricComponentsProvider(requestedComponentName);
+      if (klass) {
+        [componentViewFactory registerComponentViewClass:klass];
+        return;
+      }
     }
 
-    // Fallback 2: Try to use Paper Interop.
+    // Fallback 3: Try to use Paper Interop.
     if ([RCTLegacyViewManagerInteropComponentView isSupported:RCTNSStringFromString(requestedComponentName)]) {
       auto flavor = std::make_shared<std::string const>(requestedComponentName);
       auto componentName = ComponentName{flavor->c_str()};
@@ -90,7 +96,7 @@ using namespace facebook::react;
       return;
     }
 
-    // Fallback 3: Finally use <UnimplementedView>.
+    // Fallback 4: Finally use <UnimplementedView>.
     auto flavor = std::make_shared<std::string const>(requestedComponentName);
     auto componentName = ComponentName{flavor->c_str()};
     auto componentHandle = reinterpret_cast<ComponentHandle>(componentName);