iOS: Update RCTAlertManager to use new RCTAlertController

React/CoreModules/RCTAlertManager.mm

@@ -13,6 +13,7 @@
 #import <React/RCTConvert.h>
 #import <React/RCTLog.h>
 #import <React/RCTUtils.h>
+#import <React/RCTAlertController.h>
 
 #import "CoreModulesPlugins.h"
 
@@ -99,27 +100,7 @@ - (void)invalidate
     }
   }
 
-  UIViewController *presentingController = RCTPresentedViewController();
-  if (presentingController == nil) {
-    RCTLogError(@"Tried to display alert view but there is no application window. args: %@", @{
-      @"title" : args.title() ?: [NSNull null],
-      @"message" : args.message() ?: [NSNull null],
-      @"buttons" : RCTConvertOptionalVecToArray(
-          args.buttons(),
-          ^id(id<NSObject> element) {
-            return element;
-          })
-          ?: [NSNull null],
-      @"type" : args.type() ?: [NSNull null],
-      @"defaultValue" : args.defaultValue() ?: [NSNull null],
-      @"cancelButtonKey" : args.cancelButtonKey() ?: [NSNull null],
-      @"destructiveButtonKey" : args.destructiveButtonKey() ?: [NSNull null],
-      @"keyboardType" : args.keyboardType() ?: [NSNull null],
-    });
-    return;
-  }
-
-  UIAlertController *alertController = [UIAlertController alertControllerWithTitle:title
+  RCTAlertController *alertController = [RCTAlertController alertControllerWithTitle:title
                                                                            message:nil
                                                                     preferredStyle:UIAlertControllerStyleAlert];
   switch (type) {
@@ -170,7 +151,7 @@ - (void)invalidate
     } else if ([buttonKey isEqualToString:destructiveButtonKey]) {
       buttonStyle = UIAlertActionStyleDestructive;
     }
-    __weak UIAlertController *weakAlertController = alertController;
+    __weak RCTAlertController *weakAlertController = alertController;
     [alertController
         addAction:[UIAlertAction
                       actionWithTitle:buttonTitle
@@ -202,7 +183,7 @@ - (void)invalidate
   [_alertControllers addObject:alertController];
 
   dispatch_async(dispatch_get_main_queue(), ^{
-    [presentingController presentViewController:alertController animated:YES completion:nil];
+    [alertController show:YES completion:nil];
   });
 }
 

React/Views/RCTAlertController.h

@@ -0,0 +1,7 @@
+#import <UIKit/UIKit.h>
+
+@interface RCTAlertController : UIAlertController
+
+- (void)show:(BOOL)animated completion:(void (^)(void))completion;
+
+@end

React/Views/RCTAlertController.m

@@ -0,0 +1,25 @@
+#import "RCTAlertController.h"
+
+@interface RCTAlertController ()
+
+@property (nonatomic, strong) UIWindow *alertWindow;
+
+@end
+
+@implementation RCTAlertController
+
+- (UIWindow *)alertWindow {
+    if (_alertWindow == nil) {
+        _alertWindow = [[UIWindow alloc] initWithFrame:[[UIApplication sharedApplication] keyWindow].bounds];
+        _alertWindow.rootViewController = [UIViewController new];
+        _alertWindow.windowLevel = UIWindowLevelAlert + 1;
+    }
+    return _alertWindow;
+}
+
+- (void)show:(BOOL)animated completion:(void (^)(void))completion {
+    [self.alertWindow makeKeyAndVisible];
+    [self.alertWindow.rootViewController presentViewController:self animated:animated completion:completion];
+}
+
+@end