refactor(backend): extract convert_ecto_errors in the Mobilizon.Storage.Ecto module

And use it to log refreshing instance errors

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

lib/mobilizon/storage/ecto.ex

@@ -7,6 +7,7 @@ defmodule Mobilizon.Storage.Ecto do
   import Ecto.Changeset, only: [fetch_change: 2, put_change: 3, get_field: 2]
   alias Ecto.{Changeset, Query}
   alias Mobilizon.Web.Endpoint
+  alias Mobilizon.Web.Gettext, as: GettextBackend
   alias Mobilizon.Web.Router.Helpers, as: Routes
 
   @doc """
@@ -56,4 +57,30 @@ defmodule Mobilizon.Storage.Ecto do
       changeset
     end
   end
+
+  def convert_ecto_errors(%Ecto.Changeset{} = changeset),
+    do: Ecto.Changeset.traverse_errors(changeset, &translate_error/1)
+
+  # Translates an error message using gettext.
+  defp translate_error({msg, opts}) do
+    # Because error messages were defined within Ecto, we must
+    # call the Gettext module passing our Gettext backend. We
+    # also use the "errors" domain as translations are placed
+    # in the errors.po file.
+    # Ecto will pass the :count keyword if the error message is
+    # meant to be pluralized.
+    # On your own code and templates, depending on whether you
+    # need the message to be pluralized or not, this could be
+    # written simply as:
+    #
+    #     dngettext "errors", "1 file", "%{count} files", count
+    #     dgettext "errors", "is invalid"
+    #
+
+    if count = opts[:count] do
+      Gettext.dngettext(GettextBackend, "errors", msg, msg, count, opts)
+    else
+      Gettext.dgettext(GettextBackend, "errors", msg, opts)
+    end
+  end
 end