Rails flash messages + Twitter bootstrap + HAML + Coffee

app.js.coffee

$ ->
  $('.flash_msgs').on 'click', 'a.close', ->
    $(@).parent().hide()

app_helper.rb

module ApplicationHelper
  def flash_class(level)
    case level
      when :notice then "info"
      when :error then  "error"
      when :alert then  "warning"
    end
  end
end

app_layout.haml

- [:notice, :error, :alert].each do |level|
  - unless flash[level].blank?
    .alert.flash_msgs{ class: flash_class(level) }
      %a.close ×
      = content_tag :p, flash[level]