I need help regarding a problem that I have been wanting to solve for a long time. It is a navigation between view controllers (children) that take information from the parent. The parent is updated if there is a notification. And I want the children to update instantly along with the parent. It would be a Home controller where I show basic information. Then a button inside the Home controller that would take the View Controller that has the navigation that I mentioned.

I attach a basic scheme so you can understand it better

I would like to receive an idea even if it is basic in a programmatic way to start thinking about logic. It would also help me a lot how to make the TOP NAVIGATION BAR between steps (step 1, step 2...), and when I click on any step that opens the child corresponding to that step.

The User type is nothing more than a dictionary with Strings, Ints and some data. (I can did the notification system and works, i only mention that can work in this way)

I have also thought that when I press the home controller button it will load 4 view controllers (one for each step) and it will consume load time, right?

Any help would get me out of stress Thanks a lot!!

// Home controller
    class HomeController: UIViewController {
        
        let showSteps: UIButton = {
            let button = UIButton(type: .system)
            button.addTarget(self, action: #selector(showSteps), for: .touchUpInside)
            return button
        }()
        
        override func viewDidLoad() {
            super.viewDidLoad()
            addSubview(showSteps)
        }
        
        @objc func showSteps() {
            
            let controller = ShowSteps()
            self.present(controller, animated: true, completion: nil)
            
        }
        
    }


    // UIViewController with Navigation Bar
    class ShowSteps: UIViewController {

        private var user: User?
        
        override func viewDidLoad() {
            // update the User variable
            Service.shared.fetchUserData(uid: "XXX") { user in
                self.user = user
            }
            // listen notifications to update the user
            let nc = NotificationCenter.default
            nc.addObserver(self, selector: #selector(updateUser), name: NSNotification.Name(rawValue: "updateUser"), object: nil)
        
            /// 1. HERE I NEED TO ADD A NAVIGATION BAR IN THE TOP OF THE VIEW, THAT APPEAR IN ALL CHILDS
            /// 2. I NEED TO NAVIGATE TO OTHER STEPS WITH A FUNCTION
            
        
        }
        
        @objc func dissmissView(){
            /// 3. how can i remove from view all childs 4 in this case. but can be 6 o 7.... And then dismiss actual ShowSteps
            self.dismiss(animated: true, completion: nil)
        }
        
        @objc func updateUser() {
            // update user if notification called
            Service.shared.fetchUserData(uid: "XXX") { user in
                self.user = user
            }
        }

    }


    // that is a child example
    class VCexample1: UIViewController {
        
        /// 4. how can i see the navigation bar that has the parent? How can i send to other step from here?
        /// 5. how can i get the user variable from ShowSteps?
        /// 6. how can i navigate to other step from here?
        ///
        let BarButton: UIButton = {
            let button = UIButton(type: .system)
            button.addTarget(self, action: #selector(goToOtherStep), for: .touchUpInside)
            return button
        }()
        
        override func viewDidLoad() {
            super.viewDidLoad()
            /// show user data
        }
        

    }


    // that is a other child example
    class VCexample2: UIViewController {
        
        ...

    }
    // that is a other child example
    class VCexample3: UIViewController {
        
        ...

    }
    // that is a other child example
    class VCexample4: UIViewController {
        
        ...

    }

IS BASIC BASIC CODE. ITS NOT PERFECT. I HAVE PUT IT WITH ERRORS BUT SHORT SO THAT IT IS BETTER UNDERSTOOD

CodePudding user response：

To Me You can use PagingKit component:

PagingKit is one of the solutions you can use a lot of view controller in one view controller.

https://cocoapods.org/pods/PagingKit

this component help me.

CodePudding user response：

Simple example of delegation :

// User data
struct UserData {
    var name: String
}

// this how child get info from parentVC
protocol childVCDelegate {
    // delegete user func or var (only one may be usefull)
    func getUserData() -> UserData
    func getUserName() -> String
    var userData: UserData {get set}
}

// the parent view controller who keep the user data
class ParentVC: UIViewController, childVCDelegate {
    var userData: UserData = UserData(name: "nacho111")
    
    func getUserData() -> UserData {
        userData
    }

    func getUserName() -> String {
        userData.name
    }
}

// child VC with a label updated with user name from parentVC
class ChildVC: UIViewController {
    var label = UILabel()
    var delegate: childVCDelegate?
    
    // either a copy of user in child view
    var userInChildVC: UserData?
    
    // either access user in Parent VC
    var userInParentVC: UserData? {
        delegate?.userData
    }
    
    // fonction to register in notification center to get userData changes from parentVC
    func userDataChanged() {
        // only one of the 2 options is usefull
        userInChildVC = delegate?.getUserData()
        label.text = userInChildVC?.name
        
        label.text = delegate?.userData.name
        
        label.text = delegate?.getUserName()
    }
}

// the tab bar which create a childVC and connect it to the parent
// via delegate property of ChildVC
class TabBar: UIViewController {

    var childVC: [ChildVC] = []
    
    func createChildVC(withParentVC parentVC: ParentVC) {
        let ch1 = ChildVC()
        ch1.delegate = parentVC
        childVC.append(ch1)
    }
}