Railsのビューヘルパー内でHamlを使う

application_helper.rb

module ApplicationHelper
  def render_thumbsup_button(options)
    options[:url]    ||= thumbsup_path
    options[:method] ||= :put
    options[:count]  ||= 0
    # ローカル変数を渡したいときのみ locals が必要
    render inline: <<-HAML.strip_heredoc, type: :haml, locals: options
      .thumbsup
        = form_tag url, method: method do
          %button.btn.btn-xs
            = t('label.thumbsup')
          - if count > 0
            .span.badge
              %span.glyphicon.glyphicon-thumbs-up
              %span= count
    HAML
  end
end