How do I get Rails to stop re-loading my gems?

Question

I have a gem:

# in /Library/Ruby/Gems/1.8/gems/my_gem-1.0.0/lib/my_gem.rb
module MyGem
  def do_stuff
    ..
  end
end

And I loaded it in Rails:

# in [rails_root]/config/environment.rb:
config.gem 'my_gem', :version => '1.0.0'

And used it:

# in [rails_root]/app/controllers/application_controller.rb
class ApplicationController < ActionController::Base
  include MyGem
end

But I need to monkey-patch it a bit in an environment-specific way:

# in [rails_root]/config/environments/development.rb:
MyGem.class_eval do
  def do_stuff
    raise 'Ack! - just testing'
  end
end

Unfortunately, MyGem reloads on every request, so my monkey-patching is useless.

I've checked load_once_paths:

ActiveSupport::Dependencies.load_once_paths
# => ["/Library/Ruby/Gems/1.8/gems/my_gem-1.0.0/lib", "other stuff"]

Any idea how I can get the effect I want?

Answer 1

Seems you are working in development mode where Rails loads all classes in every request to help the developer to reflect the code changes + you have included the gem in your controller. To overcome this go to project_path/config/environments/development.rb and add this line

config.cache_classes = true 

Notice that you won't have your code changes reflected unless you restart the server.

Update 1: Also as a second solution you can add the moneky patch after you you include the gem in that controller. You can add it to the bottom of your controller file.

Update 2: A third solution (recommended) If you can add the following snippet to my_gem.rb

class ActionController::Base
  include MyGem
end

then things should work as you won't need to manually include it in your application controller.

Answer 2

If you're including the gem in your environment.rb you shouldn't need to include it in your controller.

You might want to think about how the gem hooks into ActionController - it sounds like you want to add class methods to ActionController::Base, which is quite straightforward. Have a look at how many common gems implement this.

It sounds too, like you might even want to check for the existence & value of RAILS_ENV to ensure different behaviour for different environments.