Rails- nested content_tag

You need a + to quick fix 😀

module InputHelper
  def editable_input(label,name)
    content_tag :div, :class => "field" do
      content_tag(:label,label) + # Note the + in this line
      text_field_tag(name,'', :class => 'medium new_value')
    end
  end
end

<%= editable_input 'Year Founded', 'companyStartDate' %>

Inside the block of content_tag :div, only the last returned string would be displayed.