Taking screenshot on react-native

Utils.m

- (NSURL *) takeScreenshot:(NSString *)imageName {

  UIViewController *root = [[[[UIApplication sharedApplication] delegate] window] rootViewController];
  UIGraphicsBeginImageContextWithOptions(root.view.bounds.size, NO, [UIScreen mainScreen].scale);

  [root.view.layer renderInContext:UIGraphicsGetCurrentContext()];

  UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
  NSData *imgData = UIImagePNGRepresentation(image);
  UIGraphicsEndImageContext();
  
  NSString *filePath = [NSString stringWithFormat:@"%@%@.png", NSTemporaryDirectory(), imageName];
  NSURL *fileURL = [NSURL fileURLWithPath:filePath];
  [imgData writeToFile:filePath atomically:YES];
  return fileURL;
}