LokiCat.Godot.R3.ObservableSignals 1.0.9

LokiCat.Godot.R3.ObservableSignals

R3-compatible source generator for turning [Signal] delegates in Godot C# into cached Observable<T> properties.

This package eliminates boilerplate when wiring up Godot's [Signal] system to R3's reactive observables. It generates cached, lazily-connected observables for every [Signal] delegate in your partial Godot classes.

✨ Features

• Automatically detects [Signal]-annotated delegate declarations in Godot C# scripts
• Generates type-safe Observable<T> or Observable<(T1, T2, ...)> properties
• Supports 0 to 5 parameters
• Emits clean diagnostic warnings for [Signal] delegates with more than 5 parameters
• Requires no manual wiring or Observable.Create logic
• Complies with .editorconfig and follows your R3 usage patterns
• Output is fully compatible with AddTo(this) disposal and R3 pipelines

📦 Installation

1. Add this NuGet package to your project:

dotnet add package LokiCat.Godot.R3.ObservableSignals

2. Ensure your Godot node classes are marked partial, and your [Signal] delegates are defined inside the class:

public partial class VisionCone2D : Node2D {
  [Signal]
  public delegate void BodyEnteredEventHandler(Node body);
}

3. Build your project. The generator will automatically emit:

private Observable<Node> _onBodyEntered;
public Observable<Node> OnBodyEntered =>
  this.Signal(nameof(BodyEntered), ref _onBodyEntered);

You can now subscribe:

visionCone.OnBodyEntered
  .Subscribe(body => GD.Print($"Entered: {body.Name}"))
  .AddTo(this);

✅ Supported Signal Forms

Signals with 6+ arguments will trigger a diagnostic warning and be skipped.

🧠 How It Works

• The generator looks for [Signal] delegate declarations inside partial classes.
• For each signal, it emits a private Observable<T>? field and a public Observable<T> property.
• It uses the Signal(...) extension method (also emitted by the generator) to wrap Godot.Connect(...) with Observable.Create(...).
• The generated observables are cached and lazily initialized on first access.

🛠 Example: Full Class

public partial class ButtonGroup : Node {
  [Signal]
  public delegate void PressedEventHandler(BaseButton button);
}

⬇️ Generates:

private Observable<BaseButton> _onPressed;
public Observable<BaseButton> OnPressed =>
  this.Signal(nameof(Pressed), ref _onPressed);

🧪 Troubleshooting

• Make sure your classes are marked partial
• Your [Signal] delegates must be declared inside the class
• Check .g.cs output in obj/Debug/.../generated/
• Use #nullable enable if you use nullable types in your [Signal] delegate
• You must rebuild your project to trigger generation

📄 License

MIT License

💡 Bonus Tip

Pair this generator with Chickensoft, R3, Godot, and other LokiCat Godot/.NET packages for fully reactive, event-driven game logic in idiomatic C#.