-module Rails
- class << self
- def boot!
- unless booted?
- preinitialize
- pick_boot.run
- end
- end
-
- def booted?
- defined? Rails::Initializer
- end
-
- def pick_boot
- (vendor_rails? ? VendorBoot : GemBoot).new
- end
-
- def vendor_rails?
- File.exist?("#{RAILS_ROOT}/vendor/rails")
- end
-
- def preinitialize
- load(preinitializer_path) if File.exist?(preinitializer_path)
- end
-
- def preinitializer_path
- "#{RAILS_ROOT}/config/preinitializer.rb"
- end
- end
-
- class Boot
- def run
- load_initializer
- Rails::Initializer.run(:set_load_path)
- end
- end
-
- class VendorBoot < Boot
- def load_initializer
- require "#{RAILS_ROOT}/vendor/rails/railties/lib/initializer"
- Rails::Initializer.run(:install_gem_spec_stubs)
- Rails::GemDependency.add_frozen_gem_path
- end
- end
-
- class GemBoot < Boot
- def load_initializer
- self.class.load_rubygems
- load_rails_gem
- require 'initializer'
- end
-
- def load_rails_gem
- if version = self.class.gem_version
- gem 'rails', version
- else
- gem 'rails'
- end
- rescue Gem::LoadError => load_error
- $stderr.puts %(Missing the Rails #{version} gem. Please `gem install -v=#{version} rails`, update your RAILS_GEM_VERSION setting in config/environment.rb for the Rails version you do have installed, or comment out RAILS_GEM_VERSION to use the latest version installed.)
- exit 1
- end
-
- class << self
- def rubygems_version
- Gem::RubyGemsVersion rescue nil
- end
-
- def gem_version
- if defined? RAILS_GEM_VERSION
- RAILS_GEM_VERSION
- elsif ENV.include?('RAILS_GEM_VERSION')
- ENV['RAILS_GEM_VERSION']
- else
- parse_gem_version(read_environment_rb)
- end
- end
-
- def load_rubygems
- require 'rubygems'
- min_version = '1.3.1'
- unless rubygems_version >= min_version
- $stderr.puts %Q(Rails requires RubyGems >= #{min_version} (you have #{rubygems_version}). Please `gem update --system` and try again.)
- exit 1
- end
-
- rescue LoadError
- $stderr.puts %Q(Rails requires RubyGems >= #{min_version}. Please install RubyGems and try again: http://rubygems.rubyforge.org)
- exit 1
- end
-
- def parse_gem_version(text)
- $1 if text =~ /^[^#]*RAILS_GEM_VERSION\s*=\s*["']([!~<>=]*\s*[\d.]+)["']/
- end
-
- private
- def read_environment_rb
- File.read("#{RAILS_ROOT}/config/environment.rb")
- end
- end
- end
-end
-
-# All that for this:
-Rails.boot!