Sass default configuration for rails.

lib/sass-rails/railtie.rb

@@ -1,18 +1,40 @@
 module Sass::Rails
   class Railtie < ::Rails::Railtie
     config.sass = ActiveSupport::OrderedOptions.new
+    # Establish static configuration defaults
+    # Emit scss files during stylesheet generation of scaffold
     config.sass.preferred_syntax = :scss
+    # Use expanded output instead of the sass default of :nested
+    config.sass.style            = :expanded
+    # Set the sass cache location to tmp/sass-cache
+    config.sass.cache_location   = File.join(Rails.root, "tmp/sass-cache")
+    # Write sass cache files to tmp/sass-cache for performance
+    config.sass.cache            = true
+    # Read sass cache files from tmp/sass-cache for performance
+    config.sass.read_cache       = true
+    # Display line comments above each selector as a debugging aid
+    config.sass.line_comments    = true
 
     initializer :setup_sass do |app|
+      # Only emit one kind of syntax because though we have registered two kinds of generators
       syntax     = app.config.sass.preferred_syntax.to_sym
       alt_syntax = syntax == :sass ? "scss" : "sass"
-
       app.config.generators.hide_namespace alt_syntax
+
+      # Set the stylesheet engine to the preferred syntax
       config.app_generators.stylesheet_engine syntax
+
+      # Establish configuration defaults that are evironmental in nature
+      if config.sass.full_exception.nil?
+        # Display a stack trace in the css output when in development-like environments.
+        config.sass.full_exception = app.config.consider_all_requests_local
+      end
+
     end
 
     initializer :setup_compression do |app|
       if app.config.assets.compress
+        # Use sass's css_compressor
         app.config.assets.css_compressor = CssCompressor.new
       end
     end