Recommended way to initialize Akavache with RxAppBuilder vs CreateSplatBuilder?

[rahul7720]

Hi 👋

I’m updating an app to use the newer RxAppBuilder pattern introduced in ReactiveUI 21.0.1 and I’m a bit unsure about the recommended way to initialize Akavache.

The ReactiveUI docs show this style of initialization:

IAppInstance appInstance = RxAppBuilder.CreateReactiveUIBuilder()
    .WithMaui()
    .WithAkavacheCacheDatabase<SystemJsonSerializer>(builder =>
        builder.WithApplicationName("MyApp")
               .WithSqliteProvider()
               .WithSqliteDefaults())
    .Build();

However, the Akavache documentation still shows the older CreateSplatBuilder pattern:

AppBuilder.CreateSplatBuilder()
    .WithAkavacheCacheDatabase<SystemJsonSerializer>(builder =>
        builder.WithApplicationName("MyApp")
               .WithSqliteProvider()
               .WithSqliteDefaults());

My questions are:

1. For new applications using ReactiveUI 21+ and Akavache, is RxAppBuilder.CreateReactiveUIBuilder() now the recommended best practice, or should we still be using AppBuilder.CreateSplatBuilder() for Akavache setup?

2. Are there any functional or behavioral differences between these two initialization approaches (e.g., registration order, lifetimes, logging, or composition with other services)?

3. Is there an up-to-date, canonical example for a MAUI + ReactiveUI + Akavache setup that you would recommend following?

Thanks in advance for any guidance!

[ChrisPulman]

Hi there is an extension method currently missing that will assist with this.
It will be added in the upcoming release

public static IReactiveUIBuilder UsingSplatBuilder(this IReactiveUIBuilder reactiveUIBuilder, Action<IAppBuilder>? appBuilder)
{
    appBuilder?.Invoke(reactiveUIBuilder);
    return reactiveUIBuilder;
}

In addition to this there will be a UseReactiveUI extension for Maui which will then allow the following

public static class MauiProgram
{
    /// <summary>
    /// Creates the maui application.
    /// </summary>
    /// <returns>A <see cref="MauiApp"/>.</returns>
    public static MauiApp CreateMauiApp()
    {
        var builder = MauiApp.CreateBuilder();
        builder
            .UseMauiApp<App>()
            .UseReactiveUI(reactiveUIBuilder =>
            {
                reactiveUIBuilder
                    .WithMaui()
                    .UsingSplatBuilder(splatBuilder =>
                    {
                        splatBuilder.WithAkavacheCacheDatabase<SystemJsonSerializer>(
                            builder =>
                        {
                            builder
                            .WithSqliteProvider()
                            .WithSqliteDefaults();
                        },
                            "ReactiveUI.Builder.MauiApp");
                    })
                    .BuildApp();
            })
            .ConfigureFonts(fonts =>
            {
                fonts.AddFont("OpenSans-Regular.ttf", "OpenSansRegular");
                fonts.AddFont("OpenSans-Semibold.ttf", "OpenSansSemibold");
            });

#if DEBUG
        builder.Logging.AddDebug();
#endif

        return builder.Build();
    }
}

Thank you for raising this missing element.