shiny-stores

name	shiny-stores
description	Generate and configure Shiny Stores for .NET - cross-platform key/value stores with source-generated property binding for mobile, desktop, and Blazor WebAssembly
auto_invoke	true
triggers	["IKeyValueStore","AddShinyStores","AddShinyWebAssemblyStores","StoreKeys","Shiny.Stores","BindAttribute","Shiny.Extensions.Stores","Shiny.Extensions.Stores.Web"]

Shiny Stores Skill

You are an expert in Shiny Extensions Stores, a .NET library providing cross-platform key/value store abstraction with source-generated property binding.

When to Use This Skill

Invoke this skill when the user wants to:

• Use cross-platform key/value stores (settings, secure storage, memory)
• Persist properties to a backing store using the [Bind] source generator
• Use key/value stores in Blazor WebAssembly (localStorage)
• Create custom key/value store implementations

Library Overview

Documentation: https://shinylib.net/extensions/stores/ Repository: https://github.com/shinyorg/Shiny.Extensions Packages: Shiny.Extensions.Stores, Shiny.Extensions.Stores.Web

Built-in Store Keys

Stores are registered as keyed singletons in DI using StoreKeys constants:

Key	Platform	Implementation
StoreKeys.Default ("settings")	Android	SharedPreferences
StoreKeys.Default ("settings")	iOS / Mac Catalyst / macOS (net10.0-macos)	NSUserDefaults
StoreKeys.Default ("settings")	Windows (packaged)	ApplicationData.LocalSettings
StoreKeys.Default ("settings")	Linux / other desktop / unpackaged Windows	FileKeyValueStore (JSON file)
StoreKeys.Default ("settings")	Blazor	localStorage
StoreKeys.Secure ("secure")	Android	EncryptedSharedPreferences
StoreKeys.Secure ("secure")	iOS / Mac Catalyst / macOS (net10.0-macos)	Keychain
StoreKeys.Secure ("secure")	Windows	DPAPI (packaged: ApplicationData; unpackaged: over file)
StoreKeys.Secure ("secure")	Linux / other desktop	FileKeyValueStore (JSON file, not encrypted)

net10.0-macos (plain macOS desktop apps) uses Foundation NSUserDefaults + Security.framework Keychain — the same code as iOS/Mac Catalyst — so it gets real secure storage, not the plaintext file fallback. Any target that resolves the base net10.0 asset (Linux, unpackaged Windows, other desktop) uses FileKeyValueStore, which persists to {LocalApplicationData}/{EntryAssemblyName} — so settings survive restarts instead of living only in memory. Override the folder via Shiny.Stores.FileStoreDirectory before first access. On these file fallbacks Secure is a plain JSON file and is not encrypted (unpackaged Windows keeps DPAPI over the file); do not put genuinely sensitive secrets there.

On Apple platforms (iOS, Mac Catalyst, net10.0-macos) the default store is scoped to the app's own persistent domain. NSUserDefaults.StandardUserDefaults is a search list — it resolves a key through the argument domain, the app's domain, the global domain and the registration domain — so Contains/Get/Remove ask PersistentDomainForName(bundleId) rather than the merged list, and Clear drops that domain. Without this, an ordinary key name (AutoRecord, UseMetric, Enabled) that any linked framework registered a default for reads back as present having never been written, so store.Get(key, defaultValue) and [Bind(Default = ...)] silently return the foreign value instead of the declared default. Keys the app itself wrote are unaffected — the app's own domain outranks the global and registration domains.

Setup

// Mobile / desktop — platform-native stores
services.AddShinyStores();

// Blazor WebAssembly — localStorage (still needs UseShinyStores after Build,
// because IJSRuntime is only available post-build)
services.AddShinyWebAssemblyStores();

On mobile/desktop you do not need a post-build UseShinyStores() call. Shiny.Stores.Default / Shiny.Stores.Secure are self-bootstrapping: on first access they lazily create the platform-native store (SharedPreferences / NSUserDefaults / Keychain / DPAPI) or a persistent FileKeyValueStore on desktop targets that resolve the base net10.0 asset. AddShinyStores() just registers those same instances into DI so keyed IKeyValueStore injections share them.

For Blazor (where the store needs IJSRuntime from the built provider) call host.Services.UseShinyStores() after host.Build() to snapshot the keyed IKeyValueStore registrations into the static accessor.

Static Shiny.Stores Accessor

The simplest way to read/write — self-bootstraps on first access. No initialization required for mobile/desktop.

Shiny.Stores.Default.Set("theme", "dark");
var theme = Shiny.Stores.Default.Get<string>("theme");

Shiny.Stores.Secure.Set("token", "abc123");

// Arbitrary keyed stores (must be registered with Stores.Register or via DI + UseShinyStores)
Shiny.Stores.Keyed("my-store").Set("k", "v");

Overrides / Tests / Custom Keys

// Swap any key for a test double or custom backend
Shiny.Stores.Register(StoreKeys.Default, new MemoryKeyValueStore());
Shiny.Stores.Register("redis", new RedisKeyValueStore(...));

// Or snapshot keyed IKeyValueStore registrations from a built provider:
serviceProvider.UseShinyStores();
// Equivalent low-level call:
Shiny.Stores.Initialize(serviceProvider);

// Reset between tests:
Shiny.Stores.Reset();

DI-Style Access

public class SettingsService(
    [FromKeyedServices(StoreKeys.Default)] IKeyValueStore settings,
    [FromKeyedServices(StoreKeys.Secure)] IKeyValueStore secure
)
{
    public void SaveTheme(string theme) => settings.Set("theme", theme);
    public string GetTheme() => settings.Get<string>("theme") ?? "light";
}

AddShinyStores() also registers the default store unkeyed, so a plain IKeyValueStore parameter resolves to the same instance as [FromKeyedServices(StoreKeys.Default)].

Third-party containers

Container adapters that predate .NET 8 keyed services — Prism's DryIoc container is the common one, it still sits on DryIoc 5.x — silently ignore [FromKeyedServices] and resolve the plain service type instead. The unkeyed registration above is what keeps the default store working there. StoreKeys.Secure has no such fallback (registering two different stores under one service type would be ambiguous), so when generating code for an app on a non-Microsoft container, reach for the static accessor instead:

public class SettingsService
{
    readonly IKeyValueStore secure = Shiny.Stores.Secure;   // or Shiny.Stores.Keyed("my-store")
}

A DryIoc Error.UnableToFindCtorWithAllResolvableArgs naming a type that injects a keyed store is this problem — DryIoc's ConstructorWithResolvableArguments rule reports the outermost type, not the dependency that actually failed.

Source-Generated [Bind] Properties

The DI source generator (from Shiny.Extensions.DependencyInjection) recognizes [Bind] on partial properties and emits getter/setter bodies that round-trip through the static Shiny.Stores accessor.

using Shiny;

[Singleton]
public partial class AppSettings
{
    [Bind]                                   // default store
    public partial string Theme { get; set; }

    [Bind("secure")]                         // secure store
    public partial string Token { get; set; }

    [Bind(Key = "ui_density")]               // override storage key
    public partial int Density { get; set; }
}

No INotifyPropertyChanged, no runtime reflection. Generated property bodies call Shiny.Stores.Default/Secure/Keyed(...).Get<T>(...) and .Set(...).

Store Extension Methods

store.Get<T>(key, defaultValue);        // Get with default
store.GetRequired<T>(key);              // Throws if not found
store.SetOrRemove(key, value);          // Removes if value is null
store.SetDefault<T>(key, value);        // Only sets if key doesn't exist
store.IncrementValue(key);              // Thread-safe integer increment

Code Generation Instructions

• Use AddShinyStores() for mobile/desktop, AddShinyWebAssemblyStores() for Blazor
• For persistent settings, prefer [Singleton] + [Bind] partial properties over manual Set/Get calls
• The class with [Bind] properties must be partial; properties must also be partial
• For sensitive data (tokens, credentials), pass "secure" to [Bind("secure")]
• Use Shiny.Stores.Default/Secure/Keyed(...) for direct ad-hoc access

Best Practices

1. Use [Bind] for settings classes — eliminates boilerplate, no INPC needed, AOT-clean
2. Target the secure store — always use [Bind("secure")] for sensitive values
3. Mobile/desktop needs no post-build call — Shiny.Stores self-bootstraps on first access. UseShinyStores() is only needed for Blazor (because IJSRuntime requires the built provider) or when you've registered custom keyed IKeyValueStores in DI that you want snapshotted into the static accessor
4. Use Stores.Register in tests — pair with Stores.Reset() between tests to swap in MemoryKeyValueStore or any custom double