Export CSV with Mongoid and FasterCSV

export_csv.rb

def export_inverts
  require 'fastercsv'
  inverts = Invert.all
  filename = params[:action] + ".csv"

  #this is required if you want this to work with IE
  if request.env['HTTP_USER_AGENT'] =~ /msie/i
    headers['Pragma'] = 'public'
    headers["Content-type"] = "text/plain"
    headers['Cache-Control'] = 'no-cache, must-revalidate, post-check=0, pre-check=0'
    headers['Content-Disposition'] = "attachment; filename=\"#{filename}\""
    headers['Expires'] = "0"
  else
    headers["Content-Type"] ||= 'text/csv'
    headers["Content-Disposition"] = "attachment; filename=\"#{filename}\""
    headers["Content-Transfer-Encoding"] = "binary"
  end

  csv_string = FasterCSV.generate do |csv|
    csv << ["Genus","Species","Common Name","Pet Name","Gender"]
    inverts.each do |i|
      csv << [i.scientific_name,i.scientific_name,i.common_name,i.pet_name,i.gender]
    end
  end
  render :text => csv_string
end