Improve Backend Error page

Mostly handle things properly when the front-end is missing

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

lib/web/views/error_view.ex

@@ -7,8 +7,13 @@ defmodule Mobilizon.Web.ErrorView do
   import Mobilizon.Web.Views.Utils
 
   def render("404.html", %{conn: conn}) do
-    tags = Instance.build_tags()
-    inject_tags(tags, get_locale(conn))
+    with tags <- Instance.build_tags(),
+         {:ok, html} <- inject_tags(tags, get_locale(conn)) do
+      html
+    else
+      {:error, error} ->
+        return_error(conn, error)
+    end
   end
 
   def render("404.json", _assigns) do
@@ -38,12 +43,18 @@ defmodule Mobilizon.Web.ErrorView do
     }
   end
 
-  def render("500.html", _assigns) do
+  def render("500.html", assigns) do
     Mobilizon.Config.instance_config()
     |> Keyword.get(:default_language, "en")
     |> Gettext.put_locale()
 
-    render("500_page.html", %{})
+    assigns =
+      assigns
+      |> Map.update(:details, [], & &1)
+      |> Map.put(:instance, Mobilizon.Config.instance_name())
+      |> Map.put(:contact, Mobilizon.Config.contact())
+
+    render("500_page.html", assigns)
   end
 
   # In case no render clause matches or no