From 87958a5daf0bbeeb9f3e3b7fb746539bbc9a3847 Mon Sep 17 00:00:00 2001
From: Andreas Grosam <couchdeveloper@gmail.com>
Date: Tue, 9 Dec 2025 18:19:41 +0100
Subject: [PATCH] Add configurable key prefix to AppSettingValues

- Added `prefix` property to `AppSettingValues` for runtime key prefix configuration
- Automatic bundle identifier fallback when prefix is not customized
- Thread-safe access via `OSAllocatedUnfairLock<Config>`
- Updated documentation with prefix configuration examples
---
 README.md                                 | 33 +++++++++++++++------
 Sources/Settings/SwiftUI/AppSetting.swift | 35 +++++++++++++++++++----
 2 files changed, 54 insertions(+), 14 deletions(-)

diff --git a/README.md b/README.md
index 7148ea2..d3f0c9d 100644
--- a/README.md
+++ b/README.md
@@ -46,7 +46,7 @@ dependencies: [
 Or in Xcode:
 1. File → Add Package Dependencies
 2. Enter: `https://github.com/couchdeveloper/Settings.git`
-3. Select version: 0.2.0 or later
+3. Select version: 0.3.0 or later
 
 ## Features
 
@@ -94,6 +94,26 @@ import SettingsMock
 #endif
 ```
 
+## Set a global key prefix:
+
+```swift 
+@main
+struct MyApp: App {
+    init() {
+        AppSettingValues.prefix = "myapp_"
+    }
+    
+    var body: some Scene {
+        WindowGroup {
+            MainView()
+        }
+    }
+}
+```
+
+> **Note:** When the prefix is not customized, Settings library will use the bundle identifier from the main bundle to derive a unique prefix for every key.
+
+
 ## Custom Settings Container
 
 ```swift
@@ -186,8 +206,8 @@ struct Settings {
 
 ## Requirements
 
-- Swift 6.1
-- macOS 10.15+ / iOS 13.0+ / tvOS 13.0+ / watchOS 6.0+
+- Swift 6.2
+- macOS 10.15+ / iOS 17.0+ / tvOS 17.0+ / watchOS 10.0+
 
 ## Installation
 
@@ -195,7 +215,7 @@ struct Settings {
 
 ```swift
 dependencies: [
-    .package(url: "https://github.com/couchdeveloper/UserDefaults.git", from: "0.1.0")
+    .package(url: "https://github.com/couchdeveloper/Settings.git", from: "0.3.0")
 ]
 ```
 
@@ -230,11 +250,6 @@ for try await name in Settings.$user.stream(for: \.name) {
 }
 ```
 
-## Requirements
-
-- Swift 6.1 or later
-- iOS 17.0+ / macOS 15.0+ / tvOS 17.0+ / watchOS 10.0+
-
 ## Contributing
 
 Contributions are welcome! Please see [CONTRIBUTING.md](CONTRIBUTING.md) for guidelines.
diff --git a/Sources/Settings/SwiftUI/AppSetting.swift b/Sources/Settings/SwiftUI/AppSetting.swift
index 87b110d..a78bf1c 100644
--- a/Sources/Settings/SwiftUI/AppSetting.swift
+++ b/Sources/Settings/SwiftUI/AppSetting.swift
@@ -49,16 +49,41 @@ import os
 /// AppSettingValues.resetStore()
 /// ```
 public struct AppSettingValues: __Settings_Container {
-    private static let _store = OSAllocatedUnfairLock<any UserDefaultsStore>(initialState: UserDefaults.standard)
+    struct Config {
+        var store: any UserDefaultsStore = UserDefaults.standard
+        var prefix: String? = nil
+    }
+
+    private static let _config = OSAllocatedUnfairLock<Config>(initialState: Config())
+    
     public internal(set) static var store: any UserDefaultsStore {
         get {
-            _store.withLock { store in
-                store
+            _config.withLock { config in
+                config.store
+            }
+        }
+        set {
+            _config.withLock { config in
+                config.store = newValue
             }
         }
+    }
+
+    public static var prefix: String {
+        get {
+            _config.withLock { config in
+                if let prefix = config.prefix {
+                    return prefix
+                }
+                guard let identifier = Bundle.main.bundleIdentifier else {
+                    return "app_"
+                }
+                return identifier.replacing(".", with: "_") + "_"
+            }   
+        }
         set {
-            _store.withLock { store in
-                store = newValue
+            _config.withLock { config in
+                config.prefix = newValue
             }
         }
     }