Speed up development by only reloading classes if dependencies files changed.

This can be turned off by setting `config.reload_classes_only_on_change` to false.

Extensions like Active Record should add their respective files like db/schema.rb and db/structure.sql to `config.watchable_files` if they want their changes to affect classes reloading.

Thanks to https://github.com/paneq/active_reload and Pastorino for the inspiration. <3

1 files changed, 12 insertions, 0 deletions

diff --git a/railties/lib/rails/railtie/configuration.rb b/railties/lib/rails/railtie/configuration.rb
index f888684117..cf9e4ad500 100644
--- a/railties/lib/rails/railtie/configuration.rb
+++ b/railties/lib/rails/railtie/configuration.rb
@@ -7,6 +7,18 @@ module Rails
         @@options ||= {}
       end
 
+      # Add files that should be watched for change.
+      def watchable_files
+        @@watchable_files ||= []
+      end
+
+      # Add directories that should be watched for change.
+      # The key of the hashes should be directories and the values should
+      # be an array of extensions to match in each directory.
+      def watchable_dirs
+        @@watchable_dirs ||= {}
+      end
+
       # This allows you to modify the application's middlewares from Engines.
       #
       # All operations you run on the app_middleware will be replayed on the