Separate the project type default configuration from the installer.

lib/compass/app_integration.rb

@@ -1,3 +1,24 @@
 %w(stand_alone rails merb).each do |lib|
   require "compass/app_integration/#{lib}"
 end
+
+module Compass
+  module AppIntegration
+    module Helpers
+      def lookup(project_type)
+        eval "Compass::AppIntegration::#{camelize(project_type)}"
+      rescue NameError
+        raise Compass::Error, "No application integration exists for #{project_type}"
+      end
+
+      protected
+
+      # Stolen from ActiveSupport
+      def camelize(s)
+        s.to_s.gsub(/\/(.?)/) { "::#{$1.upcase}" }.gsub(/(?:^|_)(.)/) { $1.upcase }
+      end
+
+    end
+    extend Helpers
+  end
+end

lib/compass/app_integration/rails.rb

@@ -5,4 +5,22 @@ end
 require 'compass/app_integration/rails/runtime' if defined?(ActionController::Base)
 
 
+module Compass
+  module AppIntegration
+    module Rails
+
+      extend self
+
+      def installer(*args)
+        Installer.new(*args)
+      end
+
+      def configuration
+        Compass::Configuration::Data.new.
+          extend(ConfigurationDefaults)
+      end
+
+    end
+  end
+end
 

lib/compass/app_integration/stand_alone.rb

@@ -1,3 +1,22 @@
 %w(configuration_defaults installer).each do |lib|
   require "compass/app_integration/stand_alone/#{lib}"
-end
+end
+
+module Compass
+  module AppIntegration
+    module StandAlone
+
+      extend self
+
+      def installer(*args)
+        Installer.new(*args)
+      end
+
+      def configuration
+        Compass::Configuration::Data.new.
+          extend(ConfigurationDefaults)
+      end
+
+    end
+  end
+end

lib/compass/commands/installer_command.rb

@@ -6,8 +6,8 @@ module Compass
       include Compass::Installers
 
       def configure!
-        Compass.add_configuration(installer.default_configuration)
-        Compass.add_project_configuration
+        Compass.add_configuration(options[:project_type] || :stand_alone)
+        Compass.add_project_configuration unless respond_to?(:is_project_creation?) && is_project_creation?
         Compass.add_configuration(options)
         Compass.add_configuration(installer.completed_configuration)
         if File.exists?(Compass.configuration.extensions_path)
@@ -15,19 +15,16 @@ module Compass
         end
       end
 
-      def installer
-        installer_class = if options[:bare]
-          "Compass::Installers::BareInstaller"
-        else
-          project_type = options[:project_type] || Compass.configuration.project_type
-          "Compass::AppIntegration::#{camelize(project_type)}::Installer"
-        end
-        @installer = eval("#{installer_class}.new *installer_args")
+      def app
+        @app ||= Compass::AppIntegration.lookup(Compass.configuration.project_type)
       end
 
-      # Stolen from ActiveSupport
-      def camelize(s)
-        s.to_s.gsub(/\/(.?)/) { "::#{$1.upcase}" }.gsub(/(?:^|_)(.)/) { $1.upcase }
+      def installer
+        @installer ||= if options[:bare]
+          Compass::Installers::BareInstaller.new(*installer_args)
+        else
+          app.installer(*installer_args)
+        end
       end
 
       def installer_args

lib/compass/commands/write_configuration.rb

@@ -51,7 +51,7 @@ module Compass
             end
           end
         else
-          directory projectize(File.dirname(options[:configuration_file]))
+          directory File.dirname(options[:configuration_file])
           installer.write_configuration_files(options[:configuration_file])
         end
       end

lib/compass/configuration/defaults.rb

@@ -85,6 +85,7 @@ module Compass
 
       def http_join(*segments)
         segments.map do |segment|
+          next unless segment
           segment = http_pathify(segment)
           segment[-1..-1] == "/" ? segment[0..-2] : segment
         end.join("/")
@@ -104,4 +105,4 @@ module Compass
 
     end
   end
-end
+end

lib/compass/configuration/helpers.rb

@@ -16,7 +16,16 @@ module Compass
 
       def add_configuration(config, filename = nil)
         return if config.nil?
-        data = if config.is_a?(Compass::Configuration::Data)
+
+        data = configuration_for(config, filename)
+
+        data.inherit_from!(configuration)
+        data.on_top!
+        @configuration = data
+      end
+
+      def configuration_for(config, filename = nil)
+        if config.is_a?(Compass::Configuration::Data)
           config
         elsif config.respond_to?(:read)
           Compass::Configuration::Data.new_from_string(config.read, filename)
@@ -24,12 +33,11 @@ module Compass
           Compass::Configuration::Data.new(config)
         elsif config.is_a?(String)
           Compass::Configuration::Data.new_from_file(config)
+        elsif config.is_a?(Symbol)
+          Compass::AppIntegration.lookup(config).configuration
         else
           raise "I don't know what to do with: #{config.inspect}"
         end
-        data.inherit_from!(configuration)
-        data.on_top!
-        @configuration = data
       end
 
       # Support for testing.
@@ -57,7 +65,20 @@ module Compass
       # Read the configuration file for this project
       def add_project_configuration(configuration_file_path = nil)
         configuration_file_path ||= detect_configuration_file
-        Compass.add_configuration(configuration_file_path) if configuration_file_path
+        if configuration_file_path
+
+          data = configuration_for(configuration_file_path) 
+
+          if data.raw_project_type
+            add_configuration(data.raw_project_type.to_sym)
+          else
+            add_configuration(:stand_alone)
+          end
+
+          add_configuration(data)
+        else
+          add_configuration(configuration.project_type || :stand_alone)
+        end
       end
 
       # Returns a full path to the relative path to the project directory

lib/compass/exec/project_options_parser.rb

@@ -8,6 +8,10 @@ module Compass::Exec::ProjectOptionsParser
       self.options[:configuration_file] = configuration_file
     end
 
+    opts.on('--app APP', 'Tell compass what kind of application it is integrating with. E.g. rails') do |project_type|
+      self.options[:project_type] = project_type.to_sym
+    end
+
     opts.on('--sass-dir SRC_DIR', "The source directory where you keep your sass stylesheets.") do |sass_dir|
       self.options[:sass_dir] = sass_dir
     end