Add lifecycle signal in RxViewModel

Author: lm2343635

RxController/Classes/RxViewController.swift

@@ -56,11 +56,37 @@ open class RxViewController<ViewModel: RxViewModel>: UIViewController, RxViewCon
     open override func viewDidLoad() {
         super.viewDidLoad()
 
+        viewModel.viewDidLoadSubject.onNext(())
+        
         subviews().forEach { view.addSubview($0) }
         createConstraints()
         bind().forEach { $0.disposed(by: disposeBag) }
     }
 
+    open override func viewWillAppear(_ animated: Bool) {
+        super.viewWillAppear(animated)
+        
+        viewModel.viewWillAppearSubject.onNext(())
+    }
+    
+    open override func viewDidAppear(_ animated: Bool) {
+        super.viewDidAppear(animated)
+        
+        viewModel.viewDidAppearSubject.onNext(())
+    }
+    
+    open override func viewWillDisappear(_ animated: Bool) {
+        super.viewWillDisappear(animated)
+        
+        viewModel.viewWillDisappearSubject.onNext(())
+    }
+    
+    open override func viewDidDisappear(_ animated: Bool) {
+        super.viewDidDisappear(animated)
+        
+        viewModel.viewDidDisappearSubject.onNext(())
+    }
+    
     open func subviews() -> [UIView] {
         Log.debug("[WARNING] \(type(of: self)).subview() has not been overrided")
         return []
@@ -74,10 +100,9 @@ open class RxViewController<ViewModel: RxViewModel>: UIViewController, RxViewCon
         Log.debug("[WARNING] \(type(of: self)).bind() has not been overrided.")
         return []
     }
-
+    
     /**
      Add a child view controller to the root view of the parent view controller.
-
      @param childController: a child view controller.
      */
     override open func addChild(_ childController: UIViewController) {
@@ -89,11 +114,11 @@ open class RxViewController<ViewModel: RxViewModel>: UIViewController, RxViewCon
         guard let childController = childController as? RxViewControllerProtocol else { return }
         viewModel.addChild(childController.rxViewModel)
     }
-
+    
     /**
      Add a child view controller to the a container view of the parent view controller.
      The edges of the child view controller is same as the container view by default.
-
+     
      @param childController: a child view controller.
      @param containerView: a container view of childController.
      */
@@ -102,7 +127,7 @@ open class RxViewController<ViewModel: RxViewModel>: UIViewController, RxViewCon
         // Add child view controller to a container view of the parent view controller.
         containerView.addSubview(childController.view)
         childController.didMove(toParent: self)
-
+        
         // Create constraints for the root view of the child view controller.
         childController.view.translatesAutoresizingMaskIntoConstraints = false
         childController.view.leftAnchor.constraint(equalTo: containerView.leftAnchor).isActive = true

RxController/Classes/RxViewModel.swift

@@ -29,6 +29,12 @@ import RxFlow
 
 open class RxViewModel: NSObject, Stepper {
 
+    let viewDidLoadSubject = PublishSubject<Void>()
+    let viewWillAppearSubject = PublishSubject<Void>()
+    let viewDidAppearSubject = PublishSubject<Void>()
+    let viewWillDisappearSubject = PublishSubject<Void>()
+    let viewDidDisappearSubject = PublishSubject<Void>()
+    
     public let steps = PublishRelay<Step>()
     public let events = PublishRelay<RxControllerEvent>()
     public let disposeBag = DisposeBag()
@@ -97,6 +103,25 @@ open class RxViewModel: NSObject, Stepper {
         return events
     }
 
+    public var viewDidLoad: Observable<Void> {
+        viewDidLoadSubject.asObservable()
+    }
+    
+    public var viewWillAppear: Observable<Void> {
+        viewWillAppearSubject.asObservable()
+    }
+    
+    public var viewDidAppear: Observable<Void> {
+        viewDidAppearSubject.asObservable()
+    }
+    
+    public var viewWillDisappear: Observable<Void> {
+        viewWillDisappearSubject.asObservable()
+    }
+    
+    public var viewDidDisappear: Observable<Void> {
+        viewDidDisappearSubject.asObservable()
+    }
 }
 
 extension RxViewModel: RxControllerEventBinder {}