better_component.ex

defmodule BetterComponent do
  defmodule Live do
    defmacro __using__(opts) do
      quote do
        import BetterComponent

        use Surface.LiveComponent

        def update(assigns, socket) do
          case assigns[:__event__] do
            event when is_binary(event) ->
              case handle_event(event, assigns[:__event_payload__] || %{}, socket) do
                {:noreply, socket} ->
                  {:ok, socket}

                {:reply, _map, _socket} ->
                  raise "Can't return `{:reply, socket}` from event handler for \"#{event}\" because it is being called synthetically"
              end

            _ ->
              better_update(assigns, socket)
          end
        end

        def handle_event(_event, _payload, socket) do
          {:noreply, socket}
        end

        def better_update(assigns, socket) do
          {:ok, assign(socket, assigns)}
        end

        defoverridable handle_event: 3, better_update: 2
      end
    end
  end

  defmodule LiveView do
    defmacro __using__(opts) do
      quote generated: true do
        import BetterComponent

        use Surface.LiveView

        def handle_event(_event, _payload, socket) do
          {:noreply, socket}
        end

        def handle_info({:__event__, event_name, payload}, socket) do
          case handle_event(event, assigns[:__event_payload__] || %{}, socket) do
            {:noreply, socket} ->
              {:ok, socket}

            {:reply, _map, _socket} ->
              raise "Can't return `{:reply, socket}` from event handler for \"#{event}\" because it is being called synthetically"
          end
        end

        defoverridable handle_event: 3, better_update: 2
      end
    end
  end

  defmodule Catalogue do
    defmacro __using__(opts) do
      quote generated: true do
        import BetterComponent

        def handle_event(_event, _payload, socket) do
          {:noreply, socket}
        end

        def handle_info({:__event__, event_name, payload}, socket) do
          case handle_event(event, assigns[:__event_payload__] || %{}, socket) do
            {:noreply, socket} ->
              {:ok, socket}

            {:reply, _map, _socket} ->
              raise "Can't return `{:reply, socket}` from event handler for \"#{event}\" because it is being called synthetically"
          end
        end

        defoverridable handle_event: 3
      end
    end
  end

  defmacro __using__(_) do
    quote do
      use Surface.Component
      import BetterComponent
    end
  end

  defmacro my_event(myself, name, id \\ nil) do
    quote do
      {unquote(myself), unquote(name), __MODULE__, unquote(id)}
    end
  end

  defmacro html_event(data) do
    quote do
      case unquote(data) do
        nil ->
          nil

        {target, event, _, _} ->
          %{name: event, target: target}
      end
    end
  end

  def call_event(nil, _), do: :ok

  def call_event({target, event, module, id}, payload \\ %{}) do
    if target == :live_view do
      send(self(), {:__event__, event, payload})
    else
      if is_nil(id) do
        raise "Can't call an event when a nil id is provided, make this a better message?"
      end

      Phoenix.LiveView.send_update(module, id: id, __event__: event, __event_payload__: payload)
    end
  end
end