Enables customizing name of nested spice store

Author: simonbs

Examples/SwiftUIExample/AppSpiceStore.swift

@@ -13,8 +13,7 @@ final class AppSpiceStore: SpiceStore {
         try await Task.sleep(for: .seconds(1))
         URLCache.shared.removeAllCachedResponses()
     }
-
-    let featureFlags = FeatureFlagsSpiceStore()
+    @Spice var featureFlags = FeatureFlagsSpiceStore()
 }
 
 final class FeatureFlagsSpiceStore: SpiceStore {

Examples/UIKitExample/AppSpiceStore.swift

@@ -16,8 +16,7 @@ final class AppSpiceStore: SpiceStore {
         try await Task.sleep(for: .seconds(1))
         URLCache.shared.removeAllCachedResponses()
     }
-
-    let featureFlags = FeatureFlagsSpiceStore()
+    @Spice var featureFlags = FeatureFlagsSpiceStore()
 
     private init() {}
 }

README.md

@@ -76,8 +76,7 @@ class AppSpiceStore: SpiceStore {
         try await Task.sleep(for: .seconds(1))
         URLCache.shared.removeAllCachedResponses()
     }
-
-    let featureFlags = FeatureFlagsSpiceStore()
+    @Spice var featureFlags = FeatureFlagsSpiceStore()
 }
 
 class FeatureFlagsSpiceStore: SpiceStore {
@@ -294,7 +293,7 @@ Spice stores can be nested to create a hierarchical user interface.
 
 ```swift
 final class AppSpiceStore: SpiceStore {
-    let featureFlags = FeatureFlagsSpiceStore()
+    @Spice var featureFlags = FeatureFlagsSpiceStore()
 }
 
 final class FeatureFlagsSpiceStore: SpiceStore {
@@ -303,8 +302,6 @@ final class FeatureFlagsSpiceStore: SpiceStore {
 }
 ```
 
-Note that nested spice stores should not use the `@Spice` property wrapper.
-
 ### Require Restart
 
 Setting `requiresRestart` to true will cause the app to be shut down after changing the value. Use this only when necessary, as users do not expect a restart.

Sources/Spices/Internal/MenuItems/ChildSpiceStoreMenuItem.swift

@@ -2,5 +2,6 @@ import Foundation
 
 struct ChildSpiceStoreMenuItem: MenuItem {
     let id = UUID().uuidString
+    let name: Name
     let spiceStore: any SpiceStore
 }

Sources/Spices/Internal/Storage/ThrowingStorage.swift

@@ -7,17 +7,19 @@ final class ThrowingStorage<Value>: Storage {
         }
         // swiftlint:disable:next unused_setter_value
         set {
-            fatalError("\(type(of: self)) does not support persisting values")
+            fatalError(setterMessage)
         }
     }
 
     let publisher: AnyPublisher<Value, Never>
 
     private let initialValue: Value
+    private let setterMessage: String
     private let passthroughSubject = PassthroughSubject<Value, Never>()
 
-    init(default initialValue: Value) {
+    init(default initialValue: Value, setterMessage: String) {
         self.initialValue = initialValue
+        self.setterMessage = setterMessage
         self.publisher = passthroughSubject.eraseToAnyPublisher()
     }
 }

Sources/Spices/Internal/Views/ChildSpiceStoreMenuItemView.swift

@@ -8,12 +8,12 @@ struct ChildSpiceStoreMenuItemView: View {
         NavigationLink {
             MenuItemListView(
                 items: menuItem.spiceStore.menuItems,
-                title: menuItem.spiceStore.name,
+                title: menuItem.name.rawValue,
                 dismiss: dismiss
             )
             .navigationBarTitleDisplayMode(.inline)
         } label: {
-            Text(menuItem.spiceStore.name)
+            Text(menuItem.name.rawValue)
         }
     }
 }

Sources/Spices/Spice.swift

@@ -143,7 +143,10 @@ import Foundation
     ) where Value == ButtonHandler {
         self.initialValue = wrappedValue
         self.name = Name(name)
-        self.storage = AnyStorage(ThrowingStorage(default: wrappedValue))
+        self.storage = AnyStorage(ThrowingStorage(
+            default: wrappedValue,
+            setterMessage: "Cannot set closure of Spices button."
+        ))
         self.userDefaultsStorage = nil
         self.menuItem = ButtonMenuItem(
             name: self.name,
@@ -152,7 +155,7 @@ import Foundation
         )
     }
 
-    /// Initializes a `Spice` property wrapper for a assynchronous button action.
+    /// Initializes a `Spice` property wrapper for a asynchronous button action.
     /// - Parameters:
     ///   - wrappedValue: The closure representing the button's action.
     ///   - name: The display name of the setting. Defaults to a formatted version of the property name.
@@ -164,7 +167,10 @@ import Foundation
     ) where Value == AsyncButtonHandler {
         self.initialValue = wrappedValue
         self.name = Name(name)
-        self.storage = AnyStorage(ThrowingStorage(default: wrappedValue))
+        self.storage = AnyStorage(ThrowingStorage(
+            default: wrappedValue,
+            setterMessage: "Cannot set closure of Spices button."
+        ))
         self.userDefaultsStorage = nil
         self.menuItem = AsyncButtonMenuItem(
             name: self.name,
@@ -173,6 +179,21 @@ import Foundation
         )
     }
 
+    /// Initializes a `Spice` property wrapper for a child spice store.
+    /// - Parameters:
+    ///   - wrappedValue: The spice store to creaete hierarchial navigation to.
+    ///   - name: The display name of the spice store. Defaults to a formatted version of the property name.
+    public init(wrappedValue: Value, name: String? = nil) where Value: SpiceStore {
+        self.initialValue = wrappedValue
+        self.name = Name(name)
+        self.storage = AnyStorage(ThrowingStorage(
+            default: wrappedValue,
+            setterMessage: "Cannot assign new reference to nested spice store."
+        ))
+        self.userDefaultsStorage = nil
+        self.menuItem = ChildSpiceStoreMenuItem(name: self.name, spiceStore: wrappedValue)
+    }
+
     /// A static subscript that provides access to the `Spice` property wrapper's value within a `SpiceStore`.
     ///
     /// This allows for reading and writing the value of the setting.
@@ -196,6 +217,14 @@ extension Spice: Preparable {
     func prepare(propertyName: String, ownedBy spiceStore: some SpiceStore) {
         name.rawValue = propertyName.camelCaseToNaturalText()
         userDefaultsStorage?.prepare(propertyName: propertyName, ownedBy: spiceStore)
+        if let childSpiceStore = initialValue as? any SpiceStore {
+            if childSpiceStore.parent != nil {
+                fatalError("A child spice store can only be referenced from one parent.")
+            }
+            childSpiceStore.parent = spiceStore
+            childSpiceStore.propertyName = propertyName
+            childSpiceStore.prepareIfNeeded()
+        }
     }
 }
 

Sources/Spices/SpiceStore.swift

@@ -52,15 +52,6 @@ extension SpiceStore {
         }
     }
 
-    var name: String {
-        get {
-            objc_getAssociatedObject(self, &nameKey) as? String ?? "<name unavailable>"
-        }
-        set {
-            objc_setAssociatedObject(self, &nameKey, newValue, .OBJC_ASSOCIATION_COPY_NONATOMIC)
-        }
-    }
-
     var propertyName: String {
         get {
             objc_getAssociatedObject(self, &propertyNameKey) as? String ?? "<name unavailable>"
@@ -70,21 +61,21 @@ extension SpiceStore {
         }
     }
 
-    private var isPrepared: Bool {
+    var parent: (any SpiceStore)? {
         get {
-            (objc_getAssociatedObject(self, &isPreparedKey) as? Bool) ?? false
+            objc_getAssociatedObject(self, &parentKey) as? any SpiceStore
         }
         set {
-            objc_setAssociatedObject(self, &isPreparedKey, newValue, .OBJC_ASSOCIATION_ASSIGN)
+            objc_setAssociatedObject(self, &parentKey, newValue, .OBJC_ASSOCIATION_ASSIGN)
         }
     }
 
-    private var parent: (any SpiceStore)? {
+    private var isPrepared: Bool {
         get {
-            objc_getAssociatedObject(self, &parentKey) as? any SpiceStore
+            (objc_getAssociatedObject(self, &isPreparedKey) as? Bool) ?? false
         }
         set {
-            objc_setAssociatedObject(self, &parentKey, newValue, .OBJC_ASSOCIATION_ASSIGN)
+            objc_setAssociatedObject(self, &isPreparedKey, newValue, .OBJC_ASSOCIATION_ASSIGN)
         }
     }
 
@@ -100,13 +91,10 @@ extension SpiceStore {
         prepareIfNeeded()
         let mirror = Mirror(reflecting: self)
         return mirror.children.compactMap { _, value in
-            if let spice = value as? MenuItemProvider {
-                return spice.menuItem
-            } else if let spiceStore = value as? any SpiceStore {
-                return ChildSpiceStoreMenuItem(spiceStore: spiceStore)
-            } else {
+            guard let spice = value as? MenuItemProvider else {
                 return nil
             }
+            return spice.menuItem
         }
     }
 
@@ -131,21 +119,11 @@ extension SpiceStore {
     private func prepare() {
         let mirror = Mirror(reflecting: self)
         for (name, value) in mirror.children {
-            guard let name else {
+            guard let name, let spice = value as? Preparable else {
                 continue
             }
-            if let spice = value as? Preparable {
-                let propertyName = name.removing(prefix: "_")
-                spice.prepare(propertyName: propertyName, ownedBy: self)
-            } else if let spiceStore = value as? any SpiceStore {
-                if spiceStore.parent != nil {
-                    fatalError("A child spice store can only be referenced from one parent.")
-                }
-                spiceStore.parent = self
-                spiceStore.propertyName = name
-                spiceStore.name = name.camelCaseToNaturalText()
-                spiceStore.prepareIfNeeded()
-            }
+            let propertyName = name.removing(prefix: "_")
+            spice.prepare(propertyName: propertyName, ownedBy: self)
         }
     }
 }