shop_controller.ex

defmodule UselessWeb.ShopController do
  # ...

  def new(conn, %{"hmac" => _, "shop" => shopify_domain}) do
    shop = ShopifyApp.find_shop_by(%{shopify_domain: shopify_domain})
    conn
    |> put_layout({UselessWeb.EmbeddedAppView, "layout.html"})
    |> render("show.html", shop: shop)
  end

  def new(conn, %{"shop" => shop_name}) when is_bitstring(shop_name),
    do: signup(conn, %{"shop" => %{"shopify_domain" => shop_name}})

  def new(conn, _params) do
    changeset = ShopifyApp.change_shop(%Shop{})
    render(conn, "new.html", changeset: changeset)
  end
  
  # ...
end