Update the Book Show LiveView to show authors with their roles.

lib/decentralised_book_index_web/live/book_live/show.ex

@@ -1,12 +1,14 @@
 defmodule DecentralisedBookIndexWeb.BookLive.Show do
   use DecentralisedBookIndexWeb, :live_view
 
+  alias DecentralisedBookIndex.Metadata
+
   @impl true
   def render(assigns) do
     ~H"""
     <.header>
-      Book {@book.id}
+      {@book.title}
-      <:subtitle>This is a book record from your database.</:subtitle>
+      <:subtitle>{@authors_string}</:subtitle>
 
       <:actions>
         <.link patch={~p"/books/#{@book}/edit"}>
@@ -46,13 +48,31 @@ defmodule DecentralisedBookIndexWeb.BookLive.Show do
 
   @impl true
   def handle_params(%{"id" => id}, _, socket) do
+    book = Ash.get!(Metadata.Book, id, actor: socket.assigns.current_user, load: [:author_roles])
+    author_roles = Metadata.get_author_roles_by_book_id!(book.id, load: [:author])
+    authors_string = Enum.reduce(
+      author_roles, "",
+      fn author_role, acc ->
+        if acc != "" do
+          acc <> ", "
+        else
+          acc
+        end
+        <>
+        if author_role.role == "" do
+          "#{author_role.author.name}"
+        else
+          "#{author_role.author.name} (#{author_role.role})"
+        end
+      end
+    )
+
     {:noreply,
      socket
      |> assign(:page_title, page_title(socket.assigns.live_action))
-     |> assign(
+     |> assign(:book, book)
-       :book,
+     |> assign(:authors_string, authors_string)
-       Ash.get!(DecentralisedBookIndex.Metadata.Book, id, actor: socket.assigns.current_user)
+    }
-     )}
   end
 
   defp page_title(:show), do: "Show Book"