A haml filter that let's you call client javascript in ruby, utilizing Rjs

gistfile1.rb

# In config/initializers/haml_filters.rb
module Haml
  module Filters
    module Client
      include Base

      def compile(precompiler, text)
        return if precompiler.options[:suppress_eval]
        precompiler.instance_eval do
          push_silent <<-FIRST.gsub("\n", ';') + text + <<-LAST.gsub("\n", ';')
            update_page do |page|
            page.instance_exec do
          FIRST
            end
            end
          LAST
        end
      end
    end
  end
end

# In application_helper.rb
def ready_tag string = nil
  string = yield if block_given?
  javascript_tag '$(function() {'+string+'})'
end

# Your template:
#   #testing
#     - foo = "Hello from Ruby"
#     - ready_tag do
#       :client
#         alert foo
# Output:
# <div id="testing">
#   <script type="text/javascript">
#     //<![CDATA[
#     $(function() {
#       alert("Hello from Ruby");
#     })
#     //]]>
#   </script>
# </div>