sprockets example for the sinatra application

assets.rb

require_relative 'sprockets/env_directive_processor'

class Assets
  def self.get(root)
    assets = Sprockets::Environment.new(root)

    assets.append_path File.join(root, 'assets', 'stylesheets')
    assets.append_path File.join(root, 'assets', 'javascripts')
    assets.append_path File.join(root, 'assets', 'images')

    # we are using this directive for loading development related scripts
    assets.register_preprocessor('application/javascript', Sprockets::EnvDirectiveProcessor)

    assets
  end
end

example.rb

require 'json'
require 'yaml'

require 'sprockets'
require 'sprockets-helpers'

# we need to pick boot classes of our client
require File.expand_path('../../assets',  __FILE__)
require File.expand_path('../../global_settings', __FILE__)

namespace :client_assets do
  CLIENT_PATH = File.join(File.dirname(__FILE__), '..', '..')

  task :precompile => :clean do
    precompile
  end

  def precompile
    log "Precompiling assets..."

    assets   = Assets.get(CLIENT_PATH)
    manifest = Sprockets::Manifest.new(assets, GlobalSettings.assets_manifest_path)

    Sprockets::Helpers.configure do |config|
      config.environment = assets
      config.digest      = true
      config.debug       = false
      config.prefix      = GlobalSettings.assets_prefix
      config.public_path = GlobalSettings.public_folder
      config.manifest    = manifest
    end

    assets.context_class.class_eval do
      include Sprockets::Helpers
    end
    assets.css_compressor = YUI::CssCompressor.new
    assets.js_compressor  = YUI::JavaScriptCompressor.new

    manifest.compile

    log "Done"
  end

  desc "Clean assets folder"
  task :clean do
    log "Destroying client/public/assets..."
    rm_rf GlobalSettings.assets_path, :secure => true
    log "Done"
  end

  def log(message)
    Rake.rake_output_message(message)
  end
end

begin
  Rake::Task["assets:precompile:nondigest"].enhance do
    Rake.rake_output_message('Begin enhance assets:precompile:nondigest')
    Rake::Task['client_assets:precompile'].invoke
    Rake.rake_output_message('Done enhance assets:precompile:nondigest')
  end
rescue => boom
  Rake.rake_output_message(boom.message)
end