Spark DSL extension for defining typed Phoenix channel event subscriptions.

Declares which Ash PubSub publications a channel intercepts. For each declared event, AshTypescript reads the publication's returns type and generates a typed TypeScript payload type. An event map and typed subscription helper are also generated for the channel.

The module must also be a Phoenix channel (use Phoenix.Channel) — the declared events are automatically intercepted so their payloads can be formatted with the configured output_field_formatter before reaching the client (see AshTypescript.TypedChannel.Interception). A compile warning is emitted when use Phoenix.Channel is missing.

The recommended way to get typed payloads is to use transform :some_calc on publications, pointing to a resource calculation with :auto typing. Ash auto-derives the returns type from the calculation expression. You can also use explicit returns: with an anonymous function transform.

Usage

defmodule MyAppWeb.OrgAdminChannel do
  use Phoenix.Channel
  use AshTypescript.TypedChannel

  @impl true
  def join("org_admin:" <> org_id, _payload, socket) do
    {:ok, socket}
  end

  typed_channel do
    resource MyApp.Post do
      publish :post_created
      publish :post_updated
    end

    resource MyApp.Comment do
      publish :comment_created
    end
  end
end