From 43f59f20388186864b3c6e488beef958201b9ec6 Mon Sep 17 00:00:00 2001
From: Igor Fedoronchuk <fedoronchuk@gmail.com>
Date: Thu, 21 May 2026 10:24:09 +0200
Subject: [PATCH] fix: register IndexAsCalendar at gem-require time, not via
 to_prepare

`config.to_prepare` fires after the application's initializers, which
is too late for consuming engines that `require` AA resource files
from an initializer (a pattern AA permits via `config.load_paths`).
Those resources hit:

  NameError: uninitialized constant ActiveAdmin::Views::IndexAsCalendar

Adopt the pattern used by sibling AA plugins (`active_admin_sidebar`,
etc.): `require "activeadmin"` at the top of the gem's main file so
`ActiveAdmin::Views` is guaranteed to exist, then eagerly require the
view component. The Engine class is kept (empty) so Propshaft / AA 4
can still discover `app/assets/stylesheets/activeadmin_calendar.css`.
---
 lib/activeadmin_calendar.rb        | 7 +++++++
 lib/activeadmin_calendar/engine.rb | 7 ++++---
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/lib/activeadmin_calendar.rb b/lib/activeadmin_calendar.rb
index 9f5564a..526a853 100644
--- a/lib/activeadmin_calendar.rb
+++ b/lib/activeadmin_calendar.rb
@@ -1,8 +1,15 @@
 # frozen_string_literal: true
 
+# Load ActiveAdmin first so `ActiveAdmin::Views` exists by the time we
+# register the view component. AA doesn't publish a load hook for itself
+# (only `:active_admin_controller`), and `config.to_prepare` would fire
+# too late for engines that require AA resources from an initializer.
+# Sibling plugins (active_admin_sidebar, etc.) use the same pattern.
+require "activeadmin"
 require "activeadmin_calendar/version"
 
 module ActiveadminCalendar
 end
 
 require "activeadmin_calendar/engine" if defined?(Rails)
+require "activeadmin_calendar/index_as_calendar"
diff --git a/lib/activeadmin_calendar/engine.rb b/lib/activeadmin_calendar/engine.rb
index 00a6416..ac5da81 100644
--- a/lib/activeadmin_calendar/engine.rb
+++ b/lib/activeadmin_calendar/engine.rb
@@ -3,9 +3,10 @@
 require "rails/engine"
 
 module ActiveadminCalendar
+  # Empty engine — kept so Propshaft / Tailwind can discover this gem's
+  # `app/assets/stylesheets` directory on AA 4. The view component
+  # itself is required eagerly from `lib/activeadmin_calendar.rb` so it
+  # is available before AA resources are loaded.
   class Engine < ::Rails::Engine
-    config.to_prepare do
-      require "activeadmin_calendar/index_as_calendar"
-    end
   end
 end