Sandreas.Avalonia.SimplePreferences 0.0.4

Avalonia.SimplePreferences

Cross-Platform preferences library for AvaloniaUI

Since this is a dependency free implementation of simple Preferences, you might also be able to use this in other projects apart from AvaloniaUI.

Install

📦 NuGet: dotnet add package Sandreas.Avalonia.SimplePreferences

Features

• IoC / Dependency Injection and static use possible
• No dependencies
• Implementation of custom storages possible

Limitations

This library is not meant to store secret information as in passwords, passphrases or tokens, because it does not store preferences encrypted. If you'd like to do so, it is strongly recommended to either implement your own Storages or use a completely different approach.

Default API

The default API aims to be compatible with MAUI IPreferences interface with some async extensions (see below).

var defaultValue = -1;
        
// retrieve value
var counter = Preferences.Get("Counter", defaultValue);
if (counter == defaultValue)
{
    // store value
    Preferences.Set("Counter", 1);
}

// remove single value
Preferences.Remove("Counter");

// remove all values
Preferences.Clear();

Async API

The async API works similar to the default API with some extensions regarding return types and cancellation tokens.

var cts = new CancellationTokenSource();
var defaultValue = -1;

// retrieve value
var counter = await Preferences.GetAsync("Counter", defaultValue, null, cts.Token);
if (counter == defaultValue)
{
    // store value (with success indicator)
    var success = await Preferences.SetAsync("Counter", 1, null, cts.Token);
    if (!success)
    {
        Console.WriteLine("Failed to set counter");
        return;
    }
}

// remove single value (with success indicator)
var removeSuccess = await Preferences.RemoveAsync("Counter");
if (!removeSuccess)
{
    Console.WriteLine("Failed to remove counter");
    return;
}

// remove all values (with removed items count)
// Note: This value is not accurate on some platforms, e.g. browser)
var removedItemsCount = await Preferences.ClearAsync();
Console.WriteLine($"Removed items: {removedItemsCount} ");

IoC / Dependency Injection

If you prefer IoC / Dependency injection for some reason (e.g. Unit-Testing), you can do the following:

// Program.cs
services.AddSingleton<PreferencesService>();

// ViewModels/HomeViewModel.cs
public partial class HomeViewModel : ViewModelBase
{
    private readonly PreferencesService _preferences;

    public HomeViewModel(PreferencesService prefs)
    {
        _preferences = prefs;
    }
    // ...
}

The service can be used like the static Preferences:

var defaultValue = -1;
        
// retrieve value
var counter = _preferences.Get("Counter", defaultValue);
if (counter == defaultValue)
{
    // store value
    _preferences.Set("Counter", 1);
}

// remove single value
_preferences.Remove("Counter");

// remove all values
_preferences.Clear();

Implementing storages

If you need to implement a custom storage, you can do this by implementing IAsyncPreferences or use the AbstractStorage for convenience. It's recommended to take a look at the existing storages to get an idea.

// MyCustomStorage.cs
class MyCustomStorage: AbstractStorage {
// ... implement mandatory members ...
}

// Program.cs
services.AddSingleton<PreferencesService>(s => new PreferencesService(new MyCustomStorage());
// alternatively: Preferences.Current = new MyCustomStorage();