NavigateAndLoad: Cancel loading on dismiss (#757)

* NavigateAndLoad: Cancel loading on dismiss

* Update Examples/CaseStudies/SwiftUICaseStudies/03-Navigation-NavigateAndLoad.swift

Co-authored-by: Stephen Celis <stephen.celis@gmail.com>

* Update Examples/CaseStudies/SwiftUICaseStudies/03-Navigation-Sheet-PresentAndLoad.swift

Co-authored-by: Stephen Celis <stephen.celis@gmail.com>

* Add cancellation to UIKitCaseStudies/NavigateAndLoad.swift

* Add cancellation to LoadThenNavigate studies

Co-authored-by: Stephen Celis <stephen.celis@gmail.com>

Examples/CaseStudies/SwiftUICaseStudies/03-Navigation-Lists-LoadThenNavigate.swift

@@ -26,6 +26,7 @@ struct LoadThenNavigateListState: Equatable {
 
 enum LoadThenNavigateListAction: Equatable {
   case counter(CounterAction)
+  case onDisappear
   case setNavigation(selection: UUID?)
   case setNavigationSelectionDelayCompleted(UUID)
 }
@@ -57,6 +58,9 @@ let loadThenNavigateListReducer =
       case .counter:
         return .none
 
+      case .onDisappear:
+        return .cancel(id: CancelId())
+
       case let .setNavigation(selection: .some(navigatedId)):
         for row in state.rows {
           state.rows[id: row.id]?.isActivityIndicatorVisible = row.id == navigatedId
@@ -119,6 +123,7 @@ struct LoadThenNavigateListView: View {
         }
       }
       .navigationBarTitle("Load then navigate")
+      .onDisappear { viewStore.send(.onDisappear) }
     }
   }
 }

Examples/CaseStudies/SwiftUICaseStudies/03-Navigation-LoadThenNavigate.swift

@@ -17,6 +17,7 @@ struct LoadThenNavigateState: Equatable {
 }
 
 enum LoadThenNavigateAction: Equatable {
+  case onDisappear
   case optionalCounter(CounterAction)
   case setNavigation(isActive: Bool)
   case setNavigationIsActiveDelayCompleted
@@ -38,12 +39,20 @@ let loadThenNavigateReducer =
     with: Reducer<
       LoadThenNavigateState, LoadThenNavigateAction, LoadThenNavigateEnvironment
     > { state, action, environment in
+
+      struct CancelId: Hashable {}
+
       switch action {
+
+      case .onDisappear:
+        return .cancel(id: CancelId())
+
       case .setNavigation(isActive: true):
         state.isActivityIndicatorVisible = true
         return Effect(value: .setNavigationIsActiveDelayCompleted)
           .delay(for: 1, scheduler: environment.mainQueue)
           .eraseToEffect()
+          .cancellable(id: CancelId())
 
       case .setNavigation(isActive: false):
         state.optionalCounter = nil
@@ -90,6 +99,7 @@ struct LoadThenNavigateView: View {
           }
         }
       }
+      .onDisappear { viewStore.send(.onDisappear) }
     }
     .navigationBarTitle("Load then navigate")
   }

Examples/CaseStudies/SwiftUICaseStudies/03-Navigation-NavigateAndLoad.swift

@@ -37,17 +37,19 @@ let navigateAndLoadReducer =
     with: Reducer<
       NavigateAndLoadState, NavigateAndLoadAction, NavigateAndLoadEnvironment
     > { state, action, environment in
+      struct CancelId: Hashable {}
       switch action {
       case .setNavigation(isActive: true):
         state.isNavigationActive = true
         return Effect(value: .setNavigationIsActiveDelayCompleted)
           .delay(for: 1, scheduler: environment.mainQueue)
           .eraseToEffect()
+          .cancellable(id: CancelId())
 
       case .setNavigation(isActive: false):
         state.isNavigationActive = false
         state.optionalCounter = nil
-        return .none
+        return .cancel(id: CancelId())
 
       case .setNavigationIsActiveDelayCompleted:
         state.optionalCounter = CounterState()

Examples/CaseStudies/SwiftUICaseStudies/03-Navigation-Sheet-LoadThenPresent.swift

@@ -17,6 +17,7 @@ struct LoadThenPresentState: Equatable {
 }
 
 enum LoadThenPresentAction {
+  case onDisappear
   case optionalCounter(CounterAction)
   case setSheet(isPresented: Bool)
   case setSheetIsPresentedDelayCompleted
@@ -38,12 +39,20 @@ let loadThenPresentReducer =
     with: Reducer<
       LoadThenPresentState, LoadThenPresentAction, LoadThenPresentEnvironment
     > { state, action, environment in
+
+      struct CancelId: Hashable {}
+
       switch action {
+
+      case .onDisappear:
+        return .cancel(id: CancelId())
+
       case .setSheet(isPresented: true):
         state.isActivityIndicatorVisible = true
         return Effect(value: .setSheetIsPresentedDelayCompleted)
           .delay(for: 1, scheduler: environment.mainQueue)
           .eraseToEffect()
+          .cancellable(id: CancelId())
 
       case .setSheet(isPresented: false):
         state.optionalCounter = nil
@@ -93,6 +102,7 @@ struct LoadThenPresentView: View {
         )
       }
       .navigationBarTitle("Load and present")
+      .onDisappear { viewStore.send(.onDisappear) }
     }
   }
 }

Examples/CaseStudies/SwiftUICaseStudies/03-Navigation-Sheet-PresentAndLoad.swift

@@ -35,17 +35,19 @@ let presentAndLoadReducer =
     with: Reducer<
       PresentAndLoadState, PresentAndLoadAction, PresentAndLoadEnvironment
     > { state, action, environment in
+      struct CancelId: Hashable {}
       switch action {
       case .setSheet(isPresented: true):
         state.isSheetPresented = true
         return Effect(value: .setSheetIsPresentedDelayCompleted)
           .delay(for: 1, scheduler: environment.mainQueue)
           .eraseToEffect()
+          .cancellable(id: CancelId())
 
       case .setSheet(isPresented: false):
         state.isSheetPresented = false
         state.optionalCounter = nil
-        return .none
+        return .cancel(id: CancelId())
 
       case .setSheetIsPresentedDelayCompleted:
         state.optionalCounter = CounterState()

Examples/CaseStudies/UIKitCaseStudies/LoadThenNavigate.swift

@@ -9,6 +9,7 @@ struct LazyNavigationState: Equatable {
 }
 
 enum LazyNavigationAction: Equatable {
+  case onDisappear
   case optionalCounter(CounterAction)
   case setNavigation(isActive: Bool)
   case setNavigationIsActiveDelayCompleted
@@ -30,12 +31,16 @@ let lazyNavigationReducer =
     with: Reducer<
       LazyNavigationState, LazyNavigationAction, LazyNavigationEnvironment
     > { state, action, environment in
+      struct CancelId: Hashable {}
       switch action {
+      case .onDisappear:
+        return .cancel(id: CancelId())
       case .setNavigation(isActive: true):
         state.isActivityIndicatorHidden = false
         return Effect(value: .setNavigationIsActiveDelayCompleted)
           .delay(for: 1, scheduler: environment.mainQueue)
           .eraseToEffect()
+          .cancellable(id: CancelId())
       case .setNavigation(isActive: false):
         state.optionalCounter = nil
         return .none
@@ -120,6 +125,11 @@ class LazyNavigationViewController: UIViewController {
   @objc private func loadOptionalCounterTapped() {
     self.viewStore.send(.setNavigation(isActive: true))
   }
+
+  override func viewDidDisappear(_ animated: Bool) {
+    super.viewDidDisappear(animated)
+    self.viewStore.send(.onDisappear)
+  }
 }
 
 struct LazyNavigationViewController_Previews: PreviewProvider {

Examples/CaseStudies/UIKitCaseStudies/NavigateAndLoad.swift

@@ -30,16 +30,20 @@ let eagerNavigationReducer =
     with: Reducer<
       EagerNavigationState, EagerNavigationAction, EagerNavigationEnvironment
     > { state, action, environment in
+
+      struct CancelId: Hashable {}
+
       switch action {
       case .setNavigation(isActive: true):
         state.isNavigationActive = true
         return Effect(value: .setNavigationIsActiveDelayCompleted)
           .delay(for: 1, scheduler: environment.mainQueue)
           .eraseToEffect()
+          .cancellable(id: CancelId())
       case .setNavigation(isActive: false):
         state.isNavigationActive = false
         state.optionalCounter = nil
-        return .none
+        return .cancel(id: CancelId())
       case .setNavigationIsActiveDelayCompleted:
         state.optionalCounter = CounterState()
         return .none