xplat: added ReactNativeConfig to access runtime specific config values

Summary: Each app may provide different impl for its runtime specific behaviors, then Fabric and other new infra can share the same config instance to configure stuffs.

Reviewed By: sahrens

Differential Revision: D13290319

fbshipit-source-id: 30e3eeedc6ff6ef250ed233b27e38cb7c1062b55

React/Fabric/RCTSurfacePresenter.h

@@ -11,6 +11,7 @@
 #import <React/RCTBridge.h>
 #import <React/RCTComponentViewFactory.h>
 #import <React/RCTPrimitives.h>
+#import <react/config/ReactNativeConfig.h>
 
 NS_ASSUME_NONNULL_BEGIN
 
@@ -25,7 +26,8 @@ NS_ASSUME_NONNULL_BEGIN
  */
 @interface RCTSurfacePresenter : NSObject
 
-- (instancetype)initWithBridge:(RCTBridge *)bridge;
+- (instancetype)initWithBridge:(RCTBridge *)bridge
+                        config:(std::shared_ptr<const facebook::react::ReactNativeConfig>)config;
 
 @property (nonatomic, readonly) RCTComponentViewFactory *componentViewFactory;
 

React/Fabric/RCTSurfacePresenter.mm

@@ -50,9 +50,10 @@ using namespace facebook::react;
   RCTSurfaceRegistry *_surfaceRegistry;  // Thread-safe.
   RCTBridge *_bridge; // Unsafe. We are moving away from Bridge.
   RCTBridge *_batchedBridge;
+  std::shared_ptr<const ReactNativeConfig> _reactNativeConfig;
 }
 
-- (instancetype)initWithBridge:(RCTBridge *)bridge
+- (instancetype)initWithBridge:(RCTBridge *)bridge config:(std::shared_ptr<const ReactNativeConfig>)config
 {
   if (self = [super init]) {
     _bridge = bridge;
@@ -63,6 +64,12 @@ using namespace facebook::react;
     _mountingManager = [[RCTMountingManager alloc] init];
     _mountingManager.delegate = self;
 
+    if (config != nullptr) {
+      _reactNativeConfig = config;
+    } else {
+      _reactNativeConfig = std::make_shared<const EmptyReactNativeConfig>();
+    }
+
     [[NSNotificationCenter defaultCenter] addObserver:self
                                              selector:@selector(handleBridgeWillReloadNotification:)
                                                  name:RCTBridgeWillReloadNotification
@@ -161,6 +168,8 @@ using namespace facebook::react;
 
   auto contextContainer = std::make_shared<ContextContainer>();
 
+  contextContainer->registerInstance(_reactNativeConfig);
+
   auto messageQueueThread = _batchedBridge.jsMessageThread;
   auto runtime = (facebook::jsi::Runtime *)((RCTCxxBridge *)_batchedBridge).runtime;
 

ReactCommon/config/BUCK

@@ -0,0 +1,45 @@
+load("@fbsource//tools/build_defs/apple:flag_defs.bzl", "flags", "get_debug_preprocessor_flags", "get_static_library_ios_flags")
+load("@fbsource//tools/build_defs/oss:rn_defs.bzl", "get_apple_inspector_flags", "rn_xplat_cxx_library")
+load("@fbsource//tools/build_defs:default_platform_defs.bzl", "ANDROID", "APPLE")
+load("@fbsource//tools/build_defs:glob_defs.bzl", "subdir_glob")
+
+APPLE_COMPILER_FLAGS = flags.get_flag_value(
+    get_static_library_ios_flags(),
+    "compiler_flags",
+)
+
+rn_xplat_cxx_library(
+    name = "config",
+    srcs = glob(["**/*.cpp"]),
+    header_namespace = "",
+    exported_headers = subdir_glob(
+        [
+            ("", "**/*.h"),
+        ],
+        prefix = "react/config",
+    ),
+    compiler_flags = [
+        "-fexceptions",
+        "-frtti",
+        "-std=c++14",
+        "-Wall",
+    ],
+    fbobjc_compiler_flags = APPLE_COMPILER_FLAGS,
+    fbobjc_preprocessor_flags = get_debug_preprocessor_flags() + get_apple_inspector_flags(),
+    force_static = True,
+    platforms = (ANDROID, APPLE),
+    preprocessor_flags = [
+        "-DLOG_TAG=\"ReactNative\"",
+        "-DWITH_FBSYSTRACE=1",
+    ],
+    visibility = [
+        "PUBLIC",
+    ],
+    deps = [
+        "xplat//fbsystrace:fbsystrace",
+        "xplat//folly:headers_only",
+        "xplat//folly:memory",
+        "xplat//folly:molly",
+        "xplat//third-party/glog:glog",
+    ],
+)

ReactCommon/config/ReactNativeConfig.cpp

@@ -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.
+ */
+
+#include "ReactNativeConfig.h"
+
+namespace facebook {
+namespace react {
+
+/**
+ * ReactNative configuration as provided by the hosting app.
+ * Provide a sub-class implementation to allow app specific customization.
+ */
+ReactNativeConfig::ReactNativeConfig() {}
+
+ReactNativeConfig::~ReactNativeConfig() {}
+
+EmptyReactNativeConfig::EmptyReactNativeConfig() {}
+
+bool EmptyReactNativeConfig::getBool(const std::string &param) const {
+  return false;
+}
+
+std::string EmptyReactNativeConfig::getString(const std::string &param) const {
+  return "";
+}
+
+int64_t EmptyReactNativeConfig::getInt64(const std::string &param) const {
+  return 0;
+}
+
+double EmptyReactNativeConfig::getDouble(const std::string &param) const {
+  return 0.0;
+}
+
+} // namespace react
+} // namespace facebook

ReactCommon/config/ReactNativeConfig.h

@@ -0,0 +1,44 @@
+/**
+ * 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.
+ */
+
+#pragma once
+
+#include <string>
+
+namespace facebook {
+namespace react {
+
+/**
+ * ReactNative configuration as provided by the hosting app.
+ * Provide a sub-class implementation to allow app specific customization.
+ */
+class ReactNativeConfig {
+public:
+  ReactNativeConfig();
+  virtual ~ReactNativeConfig();
+
+  virtual bool getBool(const std::string &param) const = 0;
+  virtual std::string getString(const std::string &param) const = 0;
+  virtual int64_t getInt64(const std::string &param) const = 0;
+  virtual double getDouble(const std::string &param) const = 0;
+};
+
+/**
+ * Empty configuration that will always provide "falsy" values.
+ */
+class EmptyReactNativeConfig : public ReactNativeConfig {
+public:
+  EmptyReactNativeConfig();
+
+  bool getBool(const std::string &param) const override;
+  std::string getString(const std::string &param) const override;
+  int64_t getInt64(const std::string &param) const override;
+  double getDouble(const std::string &param) const override;
+};
+
+} // namespace react
+} // namespace facebook