Accessing functions/variables inside a UITabBarController with or without global variables? - ios

Question

currently I have a layout like this with my app. I have a UITabBarcontroller as my root view controller inside app delegate, this is fine and works great.
#UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
var window: UIWindow?
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
FIRApp.configure()
window = UIWindow(frame: UIScreen.main.bounds)
window?.makeKeyAndVisible()
window?.rootViewController = Tabs()
UITabBar.appearance().tintColor = UIColor.init(r: 198, g: 214, b: 91)
UITabBar.appearance().barTintColor = UIColor.init(r: 47, g: 47, b: 47)
UINavigationBar.appearance().barTintColor = UIColor.init(r: 53, g: 57, b: 77)
UINavigationBar.appearance().tintColor = UIColor.init(r: 198, g: 214, b: 91)
However, in my layout with the tab controller, I have laid it out in a way where i have UITabBar at the top, followed by an override didload function that lays out all the views like this.
class Tabs: UITabBarController{
override func viewDidLoad() {
super.viewDidLoad()
tabBar.isTranslucent = true
let feed = feedController()
let feedArray = UINavigationController(rootViewController: feed)
let feedButton = UITabBarItem(title: nil, image: UIImage(named: "feed.png"), selectedImage: UIImage(named: "selectedimage.png"))
feedButton.imageInsets = UIEdgeInsets(top: 5, left: 0, bottom: -5, right: 0)
feedArray.tabBarItem = feedButton
let messages = messagesController()
let messagesArray = UINavigationController(rootViewController: messages)
let messagesButton = UITabBarItem(title: nil, image: UIImage(named: "messages.png"), selectedImage: UIImage(named: "selectedimage.png"))
messagesButton.imageInsets = UIEdgeInsets(top: 5, left: 0, bottom: -5, right: 0)
messagesArray.tabBarItem = messagesButton
let post = postController()
let postButton = UITabBarItem(title: nil, image: UIImage(named: "post.png"), selectedImage: UIImage(named: "selectedimage.png"))
postButton.imageInsets = UIEdgeInsets(top: 5, left: 0, bottom: -5, right: 0)
post.tabBarItem = postButton
let profile = profileController()
let profileArray = UINavigationController(rootViewController: profile)
let profileButton = UITabBarItem(title: nil, image: UIImage(named: "profile.png"), selectedImage: UIImage(named: "selectedimage.png"))
profileButton.imageInsets = UIEdgeInsets(top: 5, left: 0, bottom: -5, right: 0)
profile.tabBarItem = profileButton
let settings = settingsController()
let settingsArray = UINavigationController(rootViewController: settings)
let settingsButton = UITabBarItem(title: nil, image: UIImage(named: "settings.png"), selectedImage: UIImage(named: "selectedimage.png"))
settingsButton.imageInsets = UIEdgeInsets(top: 5, left: 0, bottom: -5, right: 0)
settingsArray.tabBarItem = settingsButton
if FIRAuth.auth()?.currentUser?.uid == nil {
DispatchQueue.main.async {
self.handleLogout()}
}
/* all views BOII */ viewControllers = [feedArray, messagesArray, post, profileArray, settingsArray]
However, when I try to access a function or whatever in a viewcontroller inside this tab controller from another viewcontroller inside. like this
class settingsController: UIViewController{
messagesController().removeMessages()
}
.......
class messagesController: UIViewController{
removeMessages(){
messages.removeAll()
messagesDictionary.removeAll()
tableView.reloadData()
print("working")
}
}
The functions get called (im putting it in a function on logout), I get the print message but anything I wanted affected on that viewcontroller does not seem to work. Currently, I have so far tried these methods (on settings controller).
I know this has to do with something with a tabbarcontroller in swift, something about how the views inside run parallel to each other.
What I did do and it worked, was put the declarations of the variables before the class in my tabs.swift file. So I took the let statements that set up the views and put them before the class was declared and under the import statements. This worked, but is this bad practice and is there a better way of doing it? As this let statements are now global.
Really would appreciate the help guys and Im so sorry for the long post, I just wanted you to try and understand what Im saying here, I'm new.

Answer 1

If your UIKit objects manipulates from current stack it won't work. Since object should be called from main thread.
DispatchQueue.main.async {
self.handleLogout()
}
I can only suggest you fast solution use next block for UI elements:
dispatch_async(dispatch_get_main_queue()) {
messages.removeAll()
messagesDictionary.removeAll()
tableView.reloadData()
}