Question

I have a Rails 3 app with a presenter that lives in lib. The relevant part looks like:

lib/channels/channel.rb:

module Channels
  class Channel
    def current_user
      ApplicationController.current_controller.try(:current_or_guest_user)
    end

    def self.find_by_key(key)
      @@channels.find { |c| c.key == key.to_sym }
    end

    private

    def self.class_initialize
      @@channels = []
      Dir.glob("#{Rails.root}/lib/channels/channel_defs/*.rb").each do |f|
        require_dependency f
        @@channels << "Channels::#{File.basename(f, '.rb').camelize}".constantize.new
      end
    end

    class_initialize
  end
end

lib/channels/channel_defs/activity.rb

module Channels
  class Activity

    def current_user
      ApplicationController.current_controller.try(:current_or_guest_user)
    end

    def accessible?
      current_user.registered_user?
    end
  end
end

ApplicationController.current_controller is a hack so our presenter can get to helpers; we set it to self in a before_filter. This of course doesn’t work in console, and I want to be able to work with Channel.accessible? in console, so I tried overriding the method like so in .irbrc:

module Channels
  class Channel
    class << self
      puts "in irbrc"
      def current_user
        User.find(475)
      end
    end
  end
end

And it seems to work when called directly:

ruby-1.9.2-p290 :002 > Channels::Channel.current_user
=> #

But not when called from a channel itself:

Channels::Channel.find_by_key(:activity).accessible?NoMethodError: undefined method `registered_user?' for nil:NilClass
    from /Users/jay/.rvm/gems/ruby-1.9.2-p290/gems/activesupport-3.0.9/lib/active_support/whiny_nil.rb:48:in `method_missing'
    from /Users/jay/src/tiptap/2t2/lib/channels/channel_defs/activity.rb:16:in `accessible?'
    from (irb):1

This is probably either something about the eigenclass vs the class, or something about the timing of loading Channels::Channel. I’ve tried adding a require channels/channel in .irbrc before we reopen the class, but that doesn’t do it… ideas?

Answer 1

In development mode the model classes are defined as temporary copies and re-defined on reload! which can make extensions like this unreliable or ineffective.

It’s better to layer this sort of hackery in as some kind of configuration option. For instance:

def current_user
  ENV['USER_ID'] ? User.find(ENV['USER_ID']) : ApplicationController.current_controller.try(:current_or_guest_user)
end

This way you can start up with any user you’d like:

USER_ID=475 rails console