Custom bindings

Protocol binding implementations are distributed separately in ByteBard.AsyncAPI.NET.Bindings. For supported protocols, add the binding package and register its parsers with the reader. For example, BindingsCollection.All registers all built-in parser implementations; protocol-specific coverage is documented in the bindings section.

To implement a binding that is not supplied, derive from the abstract generic binding class for its location: ServerBinding<T>, ChannelBinding<T>, OperationBinding<T>, or MessageBinding<T>. T is the concrete class itself and must implement the corresponding binding interface and have a parameterless constructor. A channel binding is sketched below:

public sealed class FooBinding : ChannelBinding<FooBinding>
{
    public string Foo { get; set; }
    public string Bar { get; set; }

    public override string BindingKey => "foo";

    protected override FixedFieldMap<FooBinding> FixedFieldMap => new()
    {
        { "bindingVersion", (binding, node) => { binding.BindingVersion = node.GetScalarValue(); } },
        { "foo", (binding, node) => { binding.Foo = node.GetScalarValue(); } },
        { "bar", (binding, node) => { binding.Bar = node.GetScalarValue(); } },
    };

    public override void SerializeV2(IAsyncApiWriter writer) => SerializeV3(writer);

    public override void SerializeV3(IAsyncApiWriter writer) => SerializeProperties(writer);

    public override void SerializeProperties(IAsyncApiWriter writer)
    {
        writer.WriteStartObject();
        writer.WriteRequiredProperty("foo", Foo);
        writer.WriteRequiredProperty("bar", Bar);
        writer.WriteOptionalProperty(AsyncApiConstants.BindingVersion, BindingVersion);
        writer.WriteExtensions(Extensions);
        writer.WriteEndObject();
    }
}

Register the binding parser on the reader settings' Bindings collection to enable deserialization:

var settings = new AsyncApiReaderSettings();
settings.Bindings.Add(new FooBinding());
var document = new AsyncApiStringReader(settings).Read(input, out var diagnostics);

The binding's key and serialized fields must follow the relevant AsyncAPI binding specification. Custom bindings are separate from protocol-specific binding support already covered under bindings; this page only documents the extension point. Confirm the exact parser type and signatures against the referenced package version when implementing a binding.