This project tried to provide custom MVU-first implementation to the new control interfaces of Maui (ILabel, IButton, etc.), and not rely on the MVVM-focused controls from Microsoft.Maui.Controls. Unfortunately those interfaces are missing a lot of features, and Microsoft.Maui.Core is lacking plenty of handlers (eg. NavigationView has no iOS implementation).
Since this will very likely be a multi-year effort from the Maui team, it means Fabulous.Maui can't provide a full MVU-first experience for the moment.
Instead, while waiting for the Maui team to fully migrate to the new architecture, we wanted to allow you to mix Fabulous and Microsoft.Maui.Controls-implemented widgets. But this approach is not going to work as any Microsoft.Maui.Controls widgets require child controls to be inherit from the MVVM Microsoft.Maui.Controls.View class, effectively preventing us to mix Fabulous & Maui widgets.
We might reconsider this library in the future.
In the meantime, please use Fabulous.MauiControls
Fabulous.Maui brings the great development experience of Fabulous to .NET MAUI, allowing you to take advantage of the latest cross-platform UI framework from Microsoft with a tailored declarative UI DSL and clean architecture.
Deploy to any platform supported by .NET MAUI, such as Android, iOS, macOS, Windows, Linux and more!
/// A simple Counter app
type Model =
{ Count: int }
type Msg =
| Increment
| Decrement
let init () =
{ Count = 0 }
let update msg model =
match msg with
| Increment -> { model with Count = model.Count + 1 }
| Decrement -> { model with Count = model.Count - 1 }
let view model =
Application() {
Window(
VStack(spacing = 16.) {
Image(Aspect.AspectFit, "fabulous.png")
Label($"Count is {model.Count}")
TextButton("Increment", Increment)
TextButton("Decrement", Decrement)
}
)
}You can start your new Fabulous.Maui app in a matter of seconds using the dotnet CLI templates.
For a starter guide see our Get Started with Fabulous.Maui.
dotnet new install Fabulous.Maui.Templates
dotnet new fabulous-maui -n MyAppThe full documentation for Fabulous.Maui can be found at docs.fabulous.dev/v2/maui.
Other useful links:
Additionally, we have the Fabulous Discord server where you can ask any of your Fabulous related questions.
The simplest way to show us your support is by giving this project and the Fabulous project a star.
You can also support us by becoming our sponsor on the GitHub Sponsors program.
This is a fantastic way to support all the efforts going into making Fabulous the best declarative UI framework for dotnet.
If you need support see Commercial Support section below.
Have you found a bug or have a suggestion of how to enhance Fabulous? Open an issue and we will take a look at it as soon as possible.
Do you want to contribute with a PR? PRs are always welcome, just make sure to create it from the correct branch (main) and follow the Contributor Guide.
For bigger changes, or if in doubt, make sure to talk about your contribution to the team. Either via an issue, GitHub discussion, or reach out to the team either using the Discord server.
If you would like us to provide you with:
- training and workshops,
- support services,
- and consulting services.
Feel free to contact us: [email protected]
.NET MAUI is still transitioning from the old architecture to the new one, so we need to use a hybrid approach to support both.
The Core folder contains the widgets and modifiers targeting the new architecture.
The Compatibility folder contains the widgets and modifiers targeting the old architecture.
When MAUI migrates a control to the new architecture, we will need to remove the old widget from Compatibility and add the new one to Core.
To allow to use both old and new widgets in a same app, we rely on marker interfaces to ensure compatibility:
Microsoft.Maui.IButtonare the marker interfaces from the new architecture in .NET MAUI. They are also the base marker interfaces for Core and Compatibility widgets.Fabulous.Maui.IFabButtonare marker interfaces for Core widgets.Fabulous.Maui.Compatibility.IFabCompatButtonare marker interfaces for Compatibility widgets.
graph LR;
A[Microsoft.Maui.IButton]-->B[Fabulous.Maui.Controls.IFabButton]
A-->C[Fabulous.Maui.Compatibility.IFabCompatTextButton]
B-->D[Fabulous.Maui.Controls.FabButton]
C-->E[Microsoft.Maui.Controls.Button]
You need to make sure to apply the right kind of marker interfaces to avoid casting errors.
All modifiers need to target only the corresponding marker interfaces as they directly cast to the underlying type, which will be different between old and new architecture.
On the other hand, to enable mixing old and new widgets in a same tree, all "children" modifiers (such as Layout.Children, ContentView.Content, etc) need to target the base marker interfaces (from Microsoft.Maui). e.g.
// Here, the children marker interface is Microsoft.Maui.IView
// Like this, we can pass either a Core or Compatibility widget as a child
static member inline VStack<'msg>(?spacing: float) =
CollectionBuilder<'msg, IFabCompatVerticalStackLayout, IView>(VerticalStackLayout.WidgetKey, LayoutOfView.Children)
// This textColor modifier actually relies on BindableProperty, so we need to make sure to target only the Compatibility marker interface Fabulous.Maui.Compatibility.IFabCompatButton
static member inline textColor(this: WidgetBuilder<'msg, #IFabCompatButton>, light: FabColor, ?dark: FabColor) =
this.AddScalar(Button.TextColor.WithValue(AppTheme.create light dark))