[Enhancement] HybridWebView.SetInvokeJavaScriptTarget() Multi-target support OR Generator to produce target

[Sane7222]

Hello!

First off, I love what the HybridWebView has introduced into MAUI. However, an immediate issue I encountered is the SetInvokeJavaScriptTarget() method only supports 1 object. If I have many C# classes with methods I want to call from JavaScript, then I would have to write out some duplicate class to pass in.

Related issues: #9424, #27258, #27382

A potential solution is to make a custom attribute

[AttributeUsage(AttributeTargets.Method)]
public class JsTargetAttribute : Attribute { }

Mark methods across classes and files

public interface IFormFactor {
    [JsTarget]
    public string GetFormFactor();
}

public interface IPlatform {
    [JsTarget]
    public string GetPlatform();
}

Have a generator make a source file to pass into SetInvokeJavaScriptTarget()

[Generator]
public class JsTargetGenerator : IIncrementalGenerator {
    public void Initialize(IncrementalGeneratorInitializationContext context) {
        var methods = context.SyntaxProvider.ForAttributeWithMetadataName("JsTargetAttribute");

        var source = """
        public class InvokeJsTarget {
            public string GetFormFactor() => IFormFactor.GetFormFactor();
            public string GetPlatform() => IPlatform.GetPlatform();
        }
        """;

        context.AddSource(InvokeJsTarget.g.cs, source);
    }
}

Would love to hear everyone's thoughts 🙂