Rails 3.2でコントローラーアクションの実行時に動的にSassテンプレートをCSS化する方法。 template.sass.erb => template.sass => CSS

styles_controller.rb

class StylesController
  def show
    # Local variables assign to ERb
    locals = {
      base_color: current_user.base_color
    }
 
    # Render ERb to Sass (app/views/styles/template.sass.erb)
    sass_contents = self.class.new.render_to_string('template',
                                                    formats: [:sass],
                                                    layout: false,
                                                    locals: locals)
 
    # Sass load paths
    load_paths = ['.']
 
    # add path to Compass (installed via Bundler)
    load_paths << "#{Gem.loaded_specs['compass'].full_gem_path}/frameworks/compass/stylesheets"
 
    # add path to application local stylesheets
    load_paths << Rails.root.join('app', 'assets', 'stylesheets')
 
    # Compile Sass to CSS
    css_contents = Sass.compile(sass_contents,
                                syntax: :sass,
                                load_paths: load_paths)
    logger.debug "*** css = #{css_contents}"
  end
end

template.sass.erb

// Compass
@import compass/reset
@import compass/utilities
@import compass/css3
 
// app/assets/stylesheets/shared/fonts
@import shared/fonts
 
body
  $base-color: <%= base_color || '#fff' %>