railtie

问题 OS is Ubuntu 12.04, 64 bit. New to rails. Relatively new to Ruby. Following the ruby.railstutorial.org tutorial, chapter 3. The tutorial has been updated to use ruby 2.0.0 and Rails 4.0.0.rc1. Previously the gemfile was specifying Rails 3.2.13 and not specifying Ruby version. After moving to the latest Gemfile in the tutorial, ruby 2.0.0 and Rails 4.0.0.rc1, I'm getting the following error when running rails commands. Example here is rails server user@machine:~/bin/railslearn/sample_app$

问题 I read a few documents on these arguments, but I did not understand clearly what they are, what are the differences between them and if one of them fits my needs. I need to write a piece of application which can be plugged in other application and I want to include it in other applications as a gem. Essentially I need a couple of models, one controller and no views, plus some initialization, support for configuration parameters coming from the hosting app and a generator. Am I on the right