Create a module for React Native to get IsRTL info and set ForceRTL 1/2

Summary: Create a module for React Native to get IsRTL information and set ForceRTL function.

Reviewed By: fkgozali

Differential Revision: D3446871

fbshipit-source-id: 736edf138a89d222818071370ac49dc54bda63b7

React/Modules/RCTI18nUtil.h

@@ -0,0 +1,25 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+#import <Foundation/Foundation.h>
+
+/**
+ * @experimental
+ * This is a experimental module for to expose constance IsRTL to js about the RTL status.
+ * And it allows js to force RLT status for development propose.
+ * This will also provide other i18n related utilities in the future.
+ */
+@interface RCTI18nUtil : NSObject
+
+- (BOOL)isRTL;
+- (BOOL)forceRTL;
+- (void)setForceRTL:(BOOL)value;
++ (id)sharedInstance;
+
+@end

React/Modules/RCTI18nUtil.m

@@ -0,0 +1,44 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+#import <Foundation/Foundation.h>
+
+#import "RCTI18nUtil.h"
+
+@implementation RCTI18nUtil
+
++ (id)sharedInstance {
+   static RCTI18nUtil *sharedRCTI18nUtilInstance = nil;
+   @synchronized(self) {
+     if (sharedRCTI18nUtilInstance == nil)
+      sharedRCTI18nUtilInstance = [self new];
+   }
+   return sharedRCTI18nUtilInstance;
+}
+
+- (BOOL)isRTL
+{
+  if ([self forceRTL]) return YES;
+  return NO;
+}
+
+- (BOOL)forceRTL
+{
+  BOOL rtlStatus = [[NSUserDefaults standardUserDefaults]
+                            boolForKey:@"RCTI18nUtil_forceRTL"];
+  return rtlStatus;
+}
+
+- (void)setForceRTL:(BOOL)rtlStatus
+{
+  [[NSUserDefaults standardUserDefaults] setBool:rtlStatus forKey:@"RCTI18nUtil_forceRTL"];
+  [[NSUserDefaults standardUserDefaults] synchronize];
+}
+
+@end