Rails /lib modules and

class, module, ruby, ruby-on-rails

Solution

There are two ways that files get loaded in Rails:

- It is registered in the autoload process, and you reference a constant that corresponds to the file name. For instance, if you have `app/controllers/pages_controller.rb` and reference PagesController, `app/controllers/pages_controller.rb` will automatically be loaded. This happens for a preset list of directories in the load path. This is a feature of Rails, and is not part of the normal Ruby load process.

- Files are explicitly `require`d. If a file is `require`d, Ruby looks through the entire list of paths in your load paths, and find the first case where the file you `require`d is in the load path. You can see the entire load path by inspecting $LOAD_PATH (an alias for $:).

Since `lib` is in your load path, you have two options: either name your files with the same names as the constants, so Rails will automatically pick them up when you reference the constant in question, or explicitly require the module.

I also notice that you might be confused about another thing. ApplicationController is not the root object in the system. Observe:

module MyModule
  def im_awesome
    puts "#{self} is so awesome"
  end
end

class ApplicationController < ActionController::Base
  include MyModule
end

class AnotherClass
end

AnotherClass.new.im_awesome
# NoMethodError: undefined method `im_awesome' for #<AnotherClass:0x101208ad0>

You will need to include the module into whatever class you want to use it in.

class AnotherClass
  include MyModule
end

AnotherClass.new.im_awesome
# AnotherClass is so awesome

Of course, in order to be able to include the module in the first place, you'll need to have it available (using either of the techniques above).

Problem

I am writing a custom wrapper for `open_flash_chart` plugin. It's placed in `/lib` and load it as a module in `ApplicationController`. However, I have either a problem with the Class hierarchy or some other problem. From any controller I can access `open_flash_chart` functions as `OpenFlashChart`, `Line` etc. However, in a class in a `/lib` module, it doesnt work! Any ideas?

Original source

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