Rails: Same name for a library module and a group of controllers?

Question

I'm in the process of organizing my code, so far I have successfully managed to groupcontrollers/helpers/views in folders "admin", but I used to have originally a library with the same module name "admin" that I'm not being able to call anymore. (name conflict?)

The new structure:

Directory Structure
  -> app
    -> controllers 
      -> admin #new
        -> admin_main
        -> admin_permissions

    -> Helpers
      -> admin #new
        -> admin_main_helper
        -> admin_permissions_helper

  -> lib
    -> admin
      -> pagerduty.rb

I used to be able to call my library from my helpers like this:

module Admin::AdminMainHelper #admin:: is new
  require "./lib/admin/pagerduty.rb"

  def pager_duty
    pagerduty = Admin::PagerDuty.new() #throws error after the new structure
    @on_call = pagerduty.first_on_call()
    @counts = pagerduty.open_incidents()
  end

end

The error is "uninitialized constant Admin::PagerDuty"

Do I have to rename my library to something else? or is there a way around this?

EDIT: It works if I rename my library module to "AdminLib" instead of "Admin" for example. So the question is if there is a way around this.

Have you tried `::PagerDuty.new()` instead of `Admin::PagerDuty.new()`? What about `PagerDuty.new()` only? — MrYoshiji, Aug 16 '13 at 15:51
no I don't think so, there must be a way to make it work. If not, it would be a bad thing that you can't have the same structure in the Helper & Lib & combine them... — MrYoshiji, Aug 16 '13 at 15:54

score 4 · Answer 1 · edited May 23 '17 at 12:29

4

To require dependencies the right way in Ruby you should:

rename pagerduty.rb => pager_duty.rb
require it with: require 'admin/pager_duty'

This is possible because Rails already adds your lib folder on your LOAD_PATH. This will work great in production for finished code (as libraries usually are).

But if you wish to develop your lib files in development - without the need to restart server each time you make a modification, you can change your setup like that:

add this line to you config/application.rb:

config.autoload_paths += %W(#{config.root}/lib)
remove any explicit require statements of lib files inside controllers or models (any app/* file)

This will work good as well. But it is a common antipattern. Because:

The lib code should be completely independent of your app so you can share it among applications. And if you are using the autoloading mechanism it implies it is a first-class citizen of your application. In this case it is much better to set up a new folder inside app (e.g. app/tools) and set up autoloading for it. Otherwise you can end up with a cluttered lib folder filled with app dependent code. More info here.
Autoloading will not work for classes that are already defined or are defined in multiple places (e.g. monkeypatches). More info here

edited May 23 '17 at 12:29

Community

1
1

answered Aug 16 '13 at 16:27

jurglic

3,599
1
17
13

Sure. No problem with class name. – jurglic Aug 16 '13 at 16:52
by the way, every time I change any code I need to restart the rails server now. unlike before where I only restart when I change the code in Lib – Aug 16 '13 at 21:59
yeah correct I used to restart the server when I change the lib folder which was totally okay, but now it's whenever I change anything in any controller! very weird. – Aug 17 '13 at 16:24
http://stackoverflow.com/questions/18291542/rails-nameerror-uninitialized-constant-error-after-modifying-controller-code – Aug 17 '13 at 17:33
I think you might have some inconsistencies in the naming of files and models/controllers. Which can break autoloading of app classes. Do you really have the controller code in admin/admin_main.rb? It should be admin/admin_main_controller.rb. That's definately not OK. And the controller name is then Admin::AdminMainController, right? – jurglic Aug 17 '13 at 17:40

Adrian CB · Accepted Answer · 2013-08-16T16:03:47.250

2

I think the problem lies with the load path. I think the require should be:

require "#{Rails.root}/lib/admin/pagerduty.rb"

Another solution, albeit a little heavy handed, is to load all of the lib subdirectories in the LOAD_PATH, eg:

In application.rb for config.autoload_path:

config.autoload_paths += Dir["#{config.root}/lib/**/"]

edited Aug 16 '13 at 16:03

answered Aug 16 '13 at 15:56

Adrian CB

651
3
5

Yes it works! very confusing sorry, #{Rails.root} is case sensitive by the way. – Aug 16 '13 at 16:01
If you are using Windows to run your app, you should use `Rails.root.join('lib', 'admin', 'pagerduty.rb')` (it will deal with the slash/backslash depending on the Operating System) @Newbie – MrYoshiji Aug 16 '13 at 16:03
we're not on windows machines. will test more. – Aug 16 '13 at 16:03
by the way, every time I change any code I need to restart the rails server now. unlike before where I only restart when I change the code in Lib – Aug 16 '13 at 21:53
Hopefully this link helps: http://www.williambharding.com/blog/rails/automatically-reload-modules-on-change-in-rails/ – Adrian CB Aug 17 '13 at 00:15

Rails: Same name for a library module and a group of controllers?

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