initializer.rb

require "pathname"

require 'rails/initializable'
require 'rails/application'
require 'rails/railties_path'
require 'rails/version'
require 'rails/gem_dependency'
require 'rails/rack'
require 'rails/paths'
require 'rails/core'
require 'rails/configuration'

RAILS_ENV = (ENV['RAILS_ENV'] || 'development').dup unless defined?(RAILS_ENV)

module Rails
  class Initializer
    class Error < StandardError ; end

    class Base
      class << self
        def run(&blk)
          define_method(:run, &blk)
        end

        def config=(config)
          @@config = config
        end

        def config
          @@config || Configuration.new
        end
        alias configuration config

        def gems_dependencies_loaded
          config.gems_dependencies_loaded
        end

        def plugin_loader
          @plugin_loader ||= configuration.plugin_loader.new(self)
        end
      end

      def gems_dependencies_loaded
        self.class.gems_dependencies_loaded
      end

      def plugin_loader
        self.class.plugin_loader
      end
    end

    class Runner

      attr_reader :names, :initializers
      attr_accessor :config
      alias configuration config

      def initialize(parent = nil)
        @names        = parent ? parent.names.dup        : {}
        @initializers = parent ? parent.initializers.dup : []
      end

      def add(name, options = {}, &block)
        # If :before or :after is specified, set the index to the right spot
        if other = options[:before] || options[:after]
          raise Error, "The #{other.inspect} initializer does not exist" unless @names[other]
          index = @initializers.index(@names[other])
          index += 1 if options[:after]
        end

        @initializers.insert(index || -1, block)
        @names[name] = block
      end

      def delete(name)
        @names[name].tap do |initializer|
          @initializers.delete(initializer)
          @names.delete(name)
        end
      end

      def run_initializer(initializer)
        init_block = initializer.is_a?(Proc) ? initializer : @names[initializer]
        container = Class.new(Base, &init_block).new
        container.run if container.respond_to?(:run)
      end

      def run(initializer = nil)
        Rails.configuration = Base.config = @config

        if initializer
          run_initializer(initializer)
        else
          @initializers.each {|block| run_initializer(block) }
        end
      end
    end

    def self.default
      @default ||= Runner.new
    end

    def self.run(initializer = nil, config = nil)
      # TODO: Clean this all up
      if initializer
        default.config = config
        default.run(initializer)
      else
        Rails.application = Class.new(Application)
        yield Rails.application.config if block_given?
        # Trigger the initializer
        Rails.application.new
        default.config = Rails.application.config
        default.run
      end
    end
  end

  # Initializes framework-specific settings for each of the loaded frameworks
  # (Configuration#frameworks). The available settings map to the accessors
  # on each of the corresponding Base classes.
  Initializer.default.add :initialize_framework_settings do
    configuration.frameworks.each do |framework|
      base_class = framework.to_s.camelize.constantize.const_get("Base")

      configuration.send(framework).each do |setting, value|
        base_class.send("#{setting}=", value)
      end
    end
    configuration.active_support.each do |setting, value|
      ActiveSupport.send("#{setting}=", value)
    end
  end

  # Sets +ActionController::Base#view_paths+ and +ActionMailer::Base#template_root+
  # (but only for those frameworks that are to be loaded). If the framework's
  # paths have already been set, it is not changed, otherwise it is
  # set to use Configuration#view_path.
  Initializer.default.add :initialize_framework_views do
    if configuration.frameworks.include?(:action_view)
      view_path = ActionView::PathSet.type_cast(configuration.view_path)
      ActionMailer::Base.template_root  = view_path if configuration.frameworks.include?(:action_mailer) && ActionMailer::Base.view_paths.blank?
      ActionController::Base.view_paths = view_path if configuration.frameworks.include?(:action_controller) && ActionController::Base.view_paths.blank?
    end
  end

  Initializer.default.add :initialize_metal do
    # TODO: Make Rails and metal work without ActionController
    if configuration.frameworks.include?(:action_controller)
      Rails::Rack::Metal.requested_metals = configuration.metals
      Rails::Rack::Metal.metal_paths += plugin_loader.engine_metal_paths

      configuration.middleware.insert_before(
        :"ActionDispatch::ParamsParser",
        Rails::Rack::Metal, :if => Rails::Rack::Metal.metals.any?)
    end
  end

  Initializer.default.add :check_for_unbuilt_gems do
    unbuilt_gems = config.gems.select {|gem| gem.frozen? && !gem.built? }
    if unbuilt_gems.size > 0
      # don't print if the gems:build rake tasks are being run
      unless $gems_build_rake_task
        abort <<-end_error
The following gems have native components that need to be built
#{unbuilt_gems.map { |gemm| "#{gemm.name}  #{gemm.requirement}" } * "\n  "}

You're running:
ruby #{Gem.ruby_version} at #{Gem.ruby}
rubygems #{Gem::RubyGemsVersion} at #{Gem.path * ', '}

Run `rake gems:build` to build the unbuilt gems.
        end_error
      end
    end
  end

  Initializer.default.add :load_gems do
    unless $gems_rake_task
      config.gems.each { |gem| gem.load }
    end
  end

  # Loads all plugins in <tt>config.plugin_paths</tt>.  <tt>plugin_paths</tt>
  # defaults to <tt>vendor/plugins</tt> but may also be set to a list of
  # paths, such as
  #   config.plugin_paths = ["#{RAILS_ROOT}/lib/plugins", "#{RAILS_ROOT}/vendor/plugins"]
  #
  # In the default implementation, as each plugin discovered in <tt>plugin_paths</tt> is initialized:
  # * its +lib+ directory, if present, is added to the load path (immediately after the applications lib directory)
  # * <tt>init.rb</tt> is evaluated, if present
  #
  # After all plugins are loaded, duplicates are removed from the load path.
  # If an array of plugin names is specified in config.plugins, only those plugins will be loaded
  # and they plugins will be loaded in that order. Otherwise, plugins are loaded in alphabetical
  # order.
  #
  # if config.plugins ends contains :all then the named plugins will be loaded in the given order and all other
  # plugins will be loaded in alphabetical order
  Initializer.default.add :load_plugins do
    plugin_loader.load_plugins
  end

  # TODO: Figure out if this needs to run a second time
  # load_gems

  Initializer.default.add :check_gem_dependencies do
    unloaded_gems = config.gems.reject { |g| g.loaded? }
    if unloaded_gems.size > 0
      configuration.gems_dependencies_loaded = false
      # don't print if the gems rake tasks are being run
      unless $gems_rake_task
        abort <<-end_error
Missing these required gems:
#{unloaded_gems.map { |gemm| "#{gemm.name}  #{gemm.requirement}" } * "\n  "}

You're running:
ruby #{Gem.ruby_version} at #{Gem.ruby}
rubygems #{Gem::RubyGemsVersion} at #{Gem.path * ', '}

Run `rake gems:install` to install the missing gems.
        end_error
      end
    else
      configuration.gems_dependencies_loaded = true
    end
  end

  # # bail out if gems are missing - note that check_gem_dependencies will have
  # # already called abort() unless $gems_rake_task is set
  # return unless gems_dependencies_loaded

  Initializer.default.add :load_application_initializers do
    if gems_dependencies_loaded
      Dir["#{configuration.root_path}/config/initializers/**/*.rb"].sort.each do |initializer|
        load(initializer)
      end
    end
  end

  # Fires the user-supplied after_initialize block (Configuration#after_initialize)
  Initializer.default.add :after_initialize do
    if gems_dependencies_loaded
      configuration.after_initialize_blocks.each do |block|
        block.call
      end
    end
  end

  # # Setup database middleware after initializers have run
  Initializer.default.add :initialize_database_middleware do
    if configuration.frameworks.include?(:active_record)
      if configuration.frameworks.include?(:action_controller) && ActionController::Base.session_store &&
          ActionController::Base.session_store.name == 'ActiveRecord::SessionStore'
        configuration.middleware.insert_before :"ActiveRecord::SessionStore", ActiveRecord::ConnectionAdapters::ConnectionManagement
        configuration.middleware.insert_before :"ActiveRecord::SessionStore", ActiveRecord::QueryCache
      else
        configuration.middleware.use ActiveRecord::ConnectionAdapters::ConnectionManagement
        configuration.middleware.use ActiveRecord::QueryCache
      end
    end
  end

  # TODO: Make a DSL way to limit an initializer to a particular framework

  # # Prepare dispatcher callbacks and run 'prepare' callbacks
  Initializer.default.add :prepare_dispatcher do
    next unless configuration.frameworks.include?(:action_controller)
    require 'rails/dispatcher' unless defined?(::Dispatcher)
    Dispatcher.define_dispatcher_callbacks(configuration.cache_classes)
  end

  # Routing must be initialized after plugins to allow the former to extend the routes
  # ---
  # If Action Controller is not one of the loaded frameworks (Configuration#frameworks)
  # this does nothing. Otherwise, it loads the routing definitions and sets up
  # loading module used to lazily load controllers (Configuration#controller_paths).
  Initializer.default.add :initialize_routing do
    next unless configuration.frameworks.include?(:action_controller)

    ActionController::Routing.controller_paths += configuration.controller_paths
    ActionController::Routing::Routes.add_configuration_file(configuration.routes_configuration_file)
    ActionController::Routing::Routes.reload!
  end
  #
  # # Observers are loaded after plugins in case Observers or observed models are modified by plugins.
  Initializer.default.add :load_observers do
    if gems_dependencies_loaded && configuration.frameworks.include?(:active_record)
      ActiveRecord::Base.instantiate_observers
    end
  end

  # Eager load application classes
  Initializer.default.add :load_application_classes do
    next if $rails_rake_task

    if configuration.cache_classes
      configuration.eager_load_paths.each do |load_path|
        matcher = /\A#{Regexp.escape(load_path)}(.*)\.rb\Z/
        Dir.glob("#{load_path}/**/*.rb").sort.each do |file|
          require_dependency file.sub(matcher, '\1')
        end
      end
    end
  end

  # Disable dependency loading during request cycle
  Initializer.default.add :disable_dependency_loading do
    if configuration.cache_classes && !configuration.dependency_loading
      ActiveSupport::Dependencies.unhook!
    end
  end

  # Configure generators if they were already loaded
  Initializer.default.add :initialize_generators do
    if defined?(Rails::Generators)
      Rails::Generators.no_color! unless config.generators.colorize_logging
      Rails::Generators.aliases.deep_merge! config.generators.aliases
      Rails::Generators.options.deep_merge! config.generators.options
    end
  end
end