Notifying Users Who have Commented On A Post iOS - ios

Question

I have an iOS app with Facebook functionality and a Parse backend. In the social media app, there is an ActivityViewController that shows: likes, comments, followers. That code is connected to my js cloud code for push notifications through Parse.
While I have comment notifications working great if userA comments on usersB's post (userB is notified), I want to add notification for a "UserB replied to your comment" activity portion (where userA is notified that there's been a response from UserB while it's on their post). Probably explaining that terribly, but basically pretty similar to face book's notifications in the comments portion but right now notifications are only one sided. I have been to work it, but I seem to only get users notifying themselves that they replied to a post.
I'm having a little trouble wrapping my head around the best way to implement that. The constants, cloud code and caches should be set up correctly. Code Below.
- (BOOL)textFieldShouldReturn:(UITextField *)textField {
// Comment Portion, works fine
NSString *trimmedComment = [textField.text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
if (trimmedComment.length != 0 && [self.photo objectForKey:kPAPPhotoUserKey]) {
PFObject *comment = [PFObject objectWithClassName:kPAPActivityClassKey];
[comment setObject:trimmedComment forKey:kPAPActivityContentKey]; // Set comment text
[comment setObject:[self.photo objectForKey:kPAPPhotoUserKey] forKey:kPAPActivityToUserKey]; // Set toUser
[comment setObject:[PFUser currentUser] forKey:kPAPActivityFromUserKey]; // Set fromUser
[comment setObject:kPAPActivityTypeComment forKey:kPAPActivityTypeKey];
[comment setObject:self.photo forKey:kPAPActivityPhotoKey];
PFACL *ACL = [PFACL ACLWithUser:[PFUser currentUser]];
[ACL setPublicReadAccess:YES];
[ACL setWriteAccess:YES forUser:[self.photo objectForKey:kPAPPhotoUserKey]];
comment.ACL = ACL;
[[PAPCache sharedCache] incrementCommentCountForPhoto:self.photo];
// Show HUD view
[MBProgressHUD showHUDAddedTo:self.view.superview animated:YES];
// If more than 5 seconds pass since we post a comment, stop waiting for the server to respond
NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:5.0f target:self selector:#selector(handleCommentTimeout:) userInfo:#{#"comment": comment} repeats:NO];
[comment saveEventually:^(BOOL succeeded, NSError *error) {
[timer invalidate];
if (error && error.code == kPFErrorObjectNotFound) {
[[PAPCache sharedCache] decrementCommentCountForPhoto:self.photo];
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:NSLocalizedString(#"Could not post comment", nil) message:NSLocalizedString(#"This photo is no longer available", nil) delegate:nil cancelButtonTitle:nil otherButtonTitles:#"OK", nil];
[alert show];
[self.navigationController popViewControllerAnimated:YES];
}
[[NSNotificationCenter defaultCenter] postNotificationName:PAPPhotoDetailsViewControllerUserCommentedOnPhotoNotification object:self.photo userInfo:#{#"comments": #(self.objects.count + 1)}];
[MBProgressHUD hideHUDForView:self.view.superview animated:YES];
[self loadObjects];
}];
}
//Reply portion is getting me stuck
NSString *trimmedReply = [textField.text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
if (trimmedReply.length != 0 && [self.photo objectForKey:kPAPPhotoUserKey]) {
PFObject *reply = [PFObject objectWithClassName:kPAPActivityClassKey];
[reply setObject:trimmedReply forKey:kPAPActivityContentKey]; // Set reply text
[reply setObject:[self.photo objectForKey:kPAPPhotoUserKey] forKey:kPAPActivityFromUserKey]; //CHANGED TO FromUser
[reply setObject:[PFUser currentUser] forKey:kPAPActivityToUserKey]; // Changed ToUser
[reply setObject:kPAPActivityTypeReply forKey:kPAPActivityTypeKey];
[reply setObject:self.photo forKey:kPAPActivityPhotoKey];
PFACL *ACL = [PFACL ACLWithUser:[PFUser currentUser]];
[ACL setPublicReadAccess:YES];
[ACL setWriteAccess:YES forUser:[self.photo objectForKey:kPAPPhotoUserKey]];
reply.ACL = ACL;
[[PAPCache sharedCache] incrementReplyCountForPhoto:self.photo];
// Show HUD view
[MBProgressHUD showHUDAddedTo:self.view.superview animated:YES];
// If more than 5 seconds pass since we post a reply, stop waiting for the server to respond
NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:5.0f target:self selector:#selector(handleReplyTimeout:) userInfo:#{#"reply": reply} repeats:NO];
[reply saveEventually:^(BOOL succeeded, NSError *error) {
[timer invalidate];
if (error && error.code == kPFErrorObjectNotFound) {
[[PAPCache sharedCache] decrementReplyCountForPhoto:self.photo];
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:NSLocalizedString(#"Could not post reply", nil) message:NSLocalizedString(#"This photo is no longer available", nil) delegate:nil cancelButtonTitle:nil otherButtonTitles:#"OK", nil];
[alert show];
[self.navigationController popViewControllerAnimated:YES];
}
[[NSNotificationCenter defaultCenter] postNotificationName:PAPPhotoDetailsViewControllerUserRepliedOnPhotoNotification object:self.photo userInfo:#{#"replies": #(self.objects.count + 1)}];
[MBProgressHUD hideHUDForView:self.view.superview animated:YES];
[self loadObjects];
}];
}
///^^^
[textField setText:#""];
return [textField resignFirstResponder];
}