♻️ Handle an AppcuesFrameView being registered with multiple IDs

appcues · Aug 15, 2023 · c3459fa · c3459fa
1 parent 37faf5a
commit c3459fa
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diff --git a/Sources/AppcuesKit/Presentation/ExperienceRendering/ExperienceRenderer.swift b/Sources/AppcuesKit/Presentation/ExperienceRendering/ExperienceRenderer.swift
@@ -33,8 +33,10 @@ internal enum ExperienceRendererError: Error {
 @available(iOS 13.0, *)
 internal class ExperienceRenderer: ExperienceRendering, StateMachineOwning {
 
+    // Conformance to `StateMachineOwning`.
     /// State machine for `RenderContext.modal`
     var stateMachine: ExperienceStateMachine?
+    var renderContext: RenderContext?
 
     private var stateMachines = StateMachineDirectory()
     private var potentiallyRenderableExperiences: [RenderContext: [ExperienceData]] = [:]
@@ -62,6 +64,12 @@ internal class ExperienceRenderer: ExperienceRendering, StateMachineOwning {
             existingFrameView.reset()
         }
 
+        // If the machine being started is already registered for a different context,
+        // reset it back to its unregistered state before potentially showing new content.
+        if owner.stateMachine != nil, let frameView = owner as? AppcuesFrameView {
+            frameView.reset()
+        }
+
         owner.stateMachine = ExperienceStateMachine(container: container)
         stateMachines[ownerFor: context] = owner
         if let pendingExperiences = potentiallyRenderableExperiences[context] {

diff --git a/Sources/AppcuesKit/Presentation/ExperienceRendering/StateMachineDirectory.swift b/Sources/AppcuesKit/Presentation/ExperienceRendering/StateMachineDirectory.swift
@@ -9,6 +9,7 @@
 import Foundation
 
 internal protocol StateMachineOwning: AnyObject {
+    var renderContext: RenderContext? { get set }
     @available(iOS 13.0, *)
     var stateMachine: ExperienceStateMachine? { get set }
 }
@@ -37,7 +38,15 @@ internal class StateMachineDirectory {
             stateMachines[key]?.value
         }
         set(newValue) {
+            // Enforce uniqueness (a StateMachineOwning may only be registered for a single RenderContext).
+            if let oldRenderContext = newValue?.renderContext, oldRenderContext != key {
+                stateMachines.removeValue(forKey: oldRenderContext)
+            }
+
             stateMachines[key] = WeakStateMachineOwning(newValue)
+
+            // Save the current renderContext so it can be easily removed in the above uniqueness check.
+            newValue?.renderContext = key
         }
     }
 

diff --git a/Sources/AppcuesKit/Presentation/UI/AppcuesFrameView.swift b/Sources/AppcuesKit/Presentation/UI/AppcuesFrameView.swift
@@ -16,6 +16,9 @@ public class AppcuesFrameView: UIView, StateMachineOwning {
         case fade
     }
 
+    // Managed by the StateMachineDirectory
+    internal var renderContext: RenderContext?
+
     private var _stateMachine: Any?
     @available(iOS 13.0, *)
     internal var stateMachine: ExperienceStateMachine? {