Losing namespace information in a rails namespaced model - ruby-on-rails

Question

When you create a namespaced model with rails scaffolding, you get two files. For example, this scaffold:
rails generate model Staff::Location name:string address:string
Generates these files:
/app/models/staff.rb
module Staff
def self.table_name_prefix
"staff_"
end
...
/app/models/staff/location.rb
class Staff::Location < ActiveRecord::Base
...
I am running into problems when in development mode where rails unloads the Staff module and never reloads it. This causes several annoying bugs such as Location not able to access it's table due to the missing table_name_prefix. The problem seems to crop up when I don't access the models directly, such as through a polymorphic relationship.
I can't seem to get the module loaded on a consistent basis. Is this the best practice way to do namespaced models? If it is, what am I missing?

Answer 1

Although I wasn't able to reproduce the problem in Rails 3.2.2, I've run into something like this before. The generic way to hack around this problem in development mode is through an ActionDispatch callback. Add this to config/environments/development.rb:
MyApp::Application.configure do
ActionDispatch::Callbacks.before do
load Rails.root.join('app', 'models', 'staff.rb')
end
end
Anything you do in that block will be executed before each request, so make sure you're only doing it in development mode.† Otherwise, you're going to suffer a performance hit in production.
I logged a message inside the staff.rb file and within the Staff module itself, and both messages appeared in the log for each request.
† I tried using the to_prepare callback, since that seems to be the documented way to execute code before each request only when cache_classes is false. But that only seemed to execute after restarting the application. There's at least one other open Stack Overflow question regarding this, although he's using a slightly different syntax than I used. If you can get to_prepare to work, I'd suggest that instead of before.

Answer 2

About a year later, I have finally found the answer to this question. This answer is specifically for rails 3.1. I am not sure if it is a problem in rails 3.2.
The problem occurs when setting up a model. If scaffolding is used, no helper file is generated. This would normally be in /app/helpers/staff/location_helper.rb. There are two ways to setup this file:
module Staff::LocationHelper
...
end
module Staff
module LocationHelper
...
end
end
In rails 3.1, specifically for helpers, you must use the first solution. You do not have to use it for other modules that use a namespace in other parts of the rails project. In fact, some structures in ruby require the second solution.
If you use the second solution when declaring a helper, in certain cases the Staff module in the helper file will override the module in /app/models/staff.rb. It will silently replace it with the empty Staff module in the file. This does not happen 100% of the time because helpers are not always loaded.