jets initializers haml example

haml.rb

# goes in config/initializers/haml.rb

puts "haml"

require "haml"
require "haml/template/options"

# check for a compatible Rails version when Haml is loaded
if (activesupport_spec = Gem.loaded_specs['activesupport'])
  if activesupport_spec.version.to_s < '4.0'
    raise Exception.new("\n\n** Haml now requires Rails 4.0 and later. Use Haml version 4.0.x\n\n")
  end
end

module Haml
  module Filters
    module RailsErb
      extend Plain
      extend TiltFilter
      extend PrecompiledTiltFilter
    end
  end
end

ActiveSupport.on_load(:action_view) do
  require "haml/template"

  if defined?(::Sass::Rails::SassTemplate) && app.config.assets.enabled
    require "haml/sass_rails_filter"
  end

  # Any object under ActionView::Template will be defined as the root constant with the same
  # name if it exists. If Erubi is loaded at all, ActionView::Template::Handlers::ERB::Erubi
  # will turn out to be a reference to the ::Erubi module.
  # In Rails 4.2, calling const_defined? results in odd exceptions, which seems to be
  # solved by looking for ::Erubi first.
  # However, in JRuby, the const_defined? finds it anyway, so we must make sure that it's
  # not just a reference to ::Erubi.
  if defined?(::Erubi) && const_defined?('ActionView::Template::Handlers::ERB::Erubi') &&
      ActionView::Template::Handlers::ERB::Erubi != ::Erubi
    require "haml/helpers/safe_erubi_template"
    Haml::Filters::RailsErb.template_class = Haml::SafeErubiTemplate
  else
    require "haml/helpers/safe_erubis_template"
    Haml::Filters::RailsErb.template_class = Haml::SafeErubisTemplate
  end
  Haml::Template.options[:filters] = { 'erb' => Haml::Filters::RailsErb }
end

Can you provide an example jbuilder file?