hoge_helper.rb

# # if Zero
# = switch_if(0) do
#   h1
#     ...
# # => <div class='zero' id='zero'><h1>...</h1></div>
#
# # if One
# = switch_if(1) do
#   h1
#     ...
# # => <div class='one' id='one'><h1>...</h1></div>
#
module HogeHelper
  def switch_if(num)
    if num == 0
      content_tag :div, class: 'zero', id: 'zero' do
        yield
      end
    elsif num == 1
      content_tag :div, class: 'one', id: 'one' do
        yield
      end
    else
      content_tag :div do
        yield
      end
    end
  end
end