Ability to invalidate a view

Author: anconaesselmann

Sources/LoadableView/Protocols/LoadableView/BaseLoadableView.swift

@@ -57,6 +57,8 @@ internal extension BaseLoadableView {
                 loaded(cached)
             } else {
                 switch vm.viewState {
+                case .invalidated:
+                    EmptyView()
                 case .notLoaded:
                     notLoaded()
                 case .loaded(let element):

Sources/LoadableView/Protocols/LoadableView/BaseLoadableViewModel.swift

@@ -81,6 +81,8 @@ public extension BaseLoadableViewModel {
             if !equal(oldItem, item) {
                 viewState = .loaded(item)
             }
+        case .invalidated:
+            viewState = .loaded(item)
         }
     }
 
@@ -93,6 +95,7 @@ public extension BaseLoadableViewModel {
             if !equal(oldItem, item) {
                 viewState = .loaded(newItem)
             }
+        case .invalidated: ()
         }
     }
 

Sources/LoadableView/Protocols/LoadableView/IDedLoadableViewModel.swift

@@ -101,6 +101,9 @@ public extension IDedLoadableViewModel {
 
     func refresh(showLoading: Bool) async throws {
         do {
+            guard !viewState.isInvalid else {
+                return
+            }
             guard let id = self.id else {
                 throw LoadableViewError.noId
             }
@@ -129,6 +132,7 @@ public extension IDedLoadableViewModel {
                         viewState = .loaded(item)
                     }
                 }
+            case .invalidated: ()
             }
             setIsLoading(false)
         }
@@ -155,6 +159,10 @@ public extension IDedLoadableViewModel {
         return true
     }
 
+    func invalidate() {
+        viewState = .invalidated
+    }
+
     func _refresh(ifID id: UUID, showLoading: Bool) {
         guard self.id == id as? Self.ID else {
             return

Sources/LoadableView/Protocols/LoadableView/LoadableViewModel.swift

@@ -59,6 +59,8 @@ public extension LoadableViewModel {
                         viewState = .loaded(item)
                     }
                 }
+            case .invalidated:
+                return
             }
             setIsLoading(false)
         }
@@ -81,6 +83,10 @@ public extension LoadableViewModel {
         return true
     }
 
+    func invalidate() {
+        viewState = .invalidated
+    }
+
     func _refresh(ifID id: UUID, showLoading: Bool) {
         self.refresh(showLoading: showLoading)
     }

Sources/LoadableView/ViewState.swift

@@ -4,6 +4,7 @@
 import Foundation
 
 public enum ViewState<T> {
+    case invalidated
     case notLoaded
     case loaded(T)
 }
@@ -12,13 +13,20 @@ public extension ViewState {
     var loaded: T? {
         switch self {
         case .loaded(let loaded): return loaded
-        case .notLoaded: return nil
+        case .notLoaded, .invalidated: return nil
         }
     }
 
     var hasLoaded: Bool {
         loaded != nil
     }
+
+    var isInvalid: Bool {
+        switch self {
+        case .invalidated: return true
+        case .loaded, .notLoaded: return false
+        }
+    }
 }
 
 public enum Overlay {