Move the compile action from the Actions module to the Compiler class.

Refactor the compass project compiler to be easier to read.

lib/compass/actions.rb

@@ -63,26 +63,6 @@ module Compass
       ERB.new(contents).result(ctx)
     end
 
-    # Compile one Sass file
-    def compile(sass_filename, css_filename, options)
-      if options[:force] || Sass::Plugin.exact_stylesheet_needs_update?(css_filename, sass_filename)
-        logger.record :compile, basename(sass_filename) unless options[:quiet]
-        engine = ::Sass::Engine.new(open(sass_filename).read,
-                                    :filename => sass_filename,
-                                    :line_comments => options[:line_comments],
-                                    :style => options[:style],
-                                    :css_filename => css_filename,
-                                    :load_paths => options[:load_paths],
-                                    :cache_location => options[:cache_location])
-        css_content = logger.red do
-          engine.render
-        end
-        write_file(css_filename, css_content, options.merge(:force => true))
-      else
-        logger.record :unchanged, basename(sass_filename) unless options[:quiet]
-      end
-    end
-
     def remove(file_name)
       if File.exists?(file_name)
         File.unlink file_name

lib/compass/compiler.rb

@@ -10,7 +10,11 @@ module Compass
       self.from, self.to = from, to
       self.logger = options.delete(:logger)
       self.options = options
-      self.options[:cache_location] ||= File.join(from, ".sass-cache")
+      self.options[:cache_location] ||= determine_cache_location
+    end
+
+    def determine_cache_location
+      Compass.configuration.cache_path || Sass::Plugin.options[:cache_location] || File.join(working_path, ".sass-cache")
     end
 
     def sass_files(options = {})
@@ -34,6 +38,7 @@ module Compass
       css_files.map{|css_file| File.dirname(css_file)}.uniq.sort.sort_by{|d| d.length }
     end
 
+    # Returns the sass file that needs to be compiled, if any.
     def out_of_date?
       Compass.configure_sass_plugin! unless Compass.sass_plugin_configured?
       sass_files.zip(css_files).each do |sass_filename, css_filename|
@@ -42,6 +47,7 @@ module Compass
       false
     end
 
+    # Determines if the configuration file is newer than any css file
     def new_config?
       config_file = Compass.detect_configuration_file
       return false unless config_file
@@ -52,34 +58,78 @@ module Compass
       nil
     end
 
-    def cache_location
-      Compass.configuration.cache_path || Sass::Plugin.options[:cache_location] || "./.sass-cache"
-    end
-
     def run
       if new_config?
-        FileUtils.rm_rf cache_location
+        # Wipe out the cache and force compilation if the configuration has changed.
+        FileUtils.rm_rf options[:cache_location]
         options[:force] = true
       end
+
+      # We use the Sass::Plugin to check dependencies so we have configure it.
       Compass.configure_sass_plugin! unless Compass.sass_plugin_configured?
-      target_directories.each do |dir|
-        directory dir
-      end
+
+      # Make sure the target directories exist
+      target_directories.each {|dir| directory dir}
+
+      # Compile each sass file.
       sass_files.zip(css_files).each do |sass_filename, css_filename|
         begin
-          compile sass_filename, css_filename, options
+          compile_if_required sass_filename, css_filename
         rescue Sass::SyntaxError => e
-          full_exception = Compass.configuration.environment == :development
-          logger.record :error, basename(sass_filename), "(Line #{e.sass_line}: #{e.message})"
-          contents = if Sass::SyntaxError.respond_to?(:exception_to_css)
-                       Sass::SyntaxError.exception_to_css(e, :full_exception => full_exception)
+          handle_exception(sass_filename, css_filename, e)
+        end
+      end
+    end
+
+    def compile_if_required(sass_filename, css_filename)
+      if should_compile?(sass_filename, css_filename)
+        compile sass_filename, css_filename
       else
-                       Sass::Plugin.options[:full_exception] ||= Compass.configuration.environment == :development
+        logger.record :unchanged, basename(sass_filename) unless options[:quiet]
+      end
+    end
+
+    # Compile one Sass file
+    def compile(sass_filename, css_filename)
+      logger.record :compile, basename(sass_filename) unless options[:quiet]
+      css_content = logger.red do
+        engine(sass_filename, css_filename).render
+      end
+      write_file(css_filename, css_content, options.merge(:force => true))
+    end
+
+    def should_compile?(sass_filename, css_filename)
+      options[:force] || Sass::Plugin.exact_stylesheet_needs_update?(css_filename, sass_filename)
+    end
+
+    # A sass engine for compiling a single file.
+    def engine(sass_filename, css_filename)
+      opts = options.merge :filename => sass_filename, :css_filename => css_filename
+      Sass::Engine.new(open(sass_filename).read, opts)
+    end
+
+    # Place the syntax error into the target css file,
+    # formatted to display in the browser (in development mode)
+    # if there's an error.
+    def handle_exception(sass_filename, css_filename, e)
+      logger.record :error, basename(sass_filename), "(Line #{e.sass_line}: #{e.message})"
+      write_file css_filename, error_contents(e), options.merge(:force => true)
+    end
+
+    # Haml refactored this logic in 2.3, this is backwards compatibility for either one
+    def error_contents(e)
+      if Sass::SyntaxError.respond_to?(:exception_to_css)
+        Sass::SyntaxError.exception_to_css(e, :full_exception => show_full_exception?)
+      else
+        Sass::Plugin.options[:full_exception] ||= show_full_exception?
         Sass::Plugin.send(:exception_string, e)
       end
-          write_file css_filename, contents, options.merge(:force => true)
-        end
-      end
-    end
+    end
+
+    # We don't want to show the full exception in production environments.
+    def show_full_exception?
+      Compass.configuration.environment == :development
+    end
+
   end
 end