hello_world_controller.rb

class HelloWorldController < AbstractController::Base
  include AbstractController::Rendering
  include AbstractController::Layouts
  include AbstractController::Helpers
  include AbstractController::Translation
  include AbstractController::AssetPaths
  include ActionController::UrlWriter

  # Uncomment if you want to use helpers defined in ApplicationHelper in your views
  # helper ApplicationHelper

  # Make sure your controller can find views
  self.view_paths = "app/views"

  # You can define custom helper methods to be used in views here
  # helper_method :current_admin
  # def current_admin; nil; end

  def show
    render template: "hello_world/show"
    # or, for partials:
    # render partial: "hello_world/show"
  end
end

show.html.erb

<h1>Hello, World!</h1>

usage.rb

# From your model, observer or library, call:

HelloWorldController.new.show
# => "<h1>Hello, World!</h1>\n" 

I have updated the gist. Looks like you have to call render method now -- both versions (template and partial) work for me on 3.0.4

please let me know if it doesn't work...

I had to call it the old fashioned way by going 'render :partial => "hello_world/show"'

Another GOTCHA is you'll need to set this: self.assets_dir = '/app/public' if you want to use something like image_tag in your views

yes, pretty sure both are expected behaviors

I want to render with the assets, I have to do anything else?

any idea how to get this to work on Rails 3.2, specifically with proper digested asset urls? The above code doesn't work with rails 3.2