fixes #123, block DNP creation without linked tag

lib/philomena_web/controllers/dnp_entry_controller.ex

@@ -11,6 +11,7 @@ defmodule PhilomenaWeb.DnpEntryController do
   import Ecto.Query
 
   plug PhilomenaWeb.FilterBannedUsersPlug when action in [:new, :create]
+  plug :set_tags when action in [:new, :create, :edit, :update, :create]
 
   plug :load_and_authorize_resource,
     model: DnpEntry,
@@ -83,15 +84,14 @@ defmodule PhilomenaWeb.DnpEntryController do
 
     render(conn, "new.html",
       title: "New DNP Listing",
-      changeset: changeset,
+      changeset: changeset
-      selectable_tags: selectable_tags(conn)
     )
   end
 
   def create(conn, %{"dnp_entry" => dnp_entry_params}) do
     case DnpEntries.create_dnp_entry(
            conn.assigns.current_user,
-           selectable_tags(conn),
+           conn.assigns.selectable_tags,
            dnp_entry_params
          ) do
       {:ok, dnp_entry} ->
@@ -100,7 +100,7 @@ defmodule PhilomenaWeb.DnpEntryController do
         |> redirect(to: Routes.dnp_entry_path(conn, :show, dnp_entry))
 
       {:error, changeset} ->
-        render(conn, "new.html", changeset: changeset, selectable_tags: selectable_tags(conn))
+        render(conn, "new.html", changeset: changeset)
     end
   end
 
@@ -109,15 +109,14 @@ defmodule PhilomenaWeb.DnpEntryController do
 
     render(conn, "edit.html",
       title: "Editing DNP Listing",
-      changeset: changeset,
+      changeset: changeset
-      selectable_tags: selectable_tags(conn)
     )
   end
 
   def update(conn, %{"dnp_entry" => dnp_entry_params}) do
     case DnpEntries.update_dnp_entry(
            conn.assigns.dnp_entry,
-           selectable_tags(conn),
+           conn.assigns.selectable_tags,
            dnp_entry_params
          ) do
       {:ok, dnp_entry} ->
@@ -126,7 +125,7 @@ defmodule PhilomenaWeb.DnpEntryController do
         |> redirect(to: Routes.dnp_entry_path(conn, :show, dnp_entry))
 
       {:error, changeset} ->
-        render(conn, "edit.html", changeset: changeset, selectable_tags: selectable_tags(conn))
+        render(conn, "edit.html", changeset: changeset)
     end
   end
 
@@ -174,4 +173,16 @@ defmodule PhilomenaWeb.DnpEntryController do
         conn
     end
   end
+
+  defp set_tags(conn, _opts) do
+    tags = selectable_tags(conn)
+
+    case tags do
+      [] ->
+        PhilomenaWeb.NotAuthorizedPlug.call(conn)
+
+      _ ->
+        assign(conn, :selectable_tags, tags)
+    end
+  end
 end