If you, like me, have tried to use helpers to generate complex chunks of HTML programmaticly, then you will have noticed that content_tag doesn’t really cut it for large chunks of HTML

content_tag will render the HTML inline unless you manually insert line breaks and tabs in order to make it readable, not to mention you end up with a horribly nested set of methods wrapping around the content you want to display

Looking something a little like this

def render_user_status
  if user_signed_in?
    inner_html = content_tag(:span, "Signed in as #{current_user.email}. Not you? \n #{link_to("Sign out", destroy_user_session_path)}")
  else
    inner_html = content_tag(:span, "#{link_to("Sign up", new_user_registration_path)} \n or \n #{link_to("Sign in", new_user_session_path)}")
  end
  return content_tag(:div, inner_html, :id => "user_nav")
end

As you can see the code looks quite unreadable, and it’s almost backwards in the way that it is generated, I’m creating the inner HTML first, and then wrapping it inside a div depending on if the user is logged in or not, there must be a better way to achieve the same result, while making it look nicer

Enter Builder

The builder gem is something that I have used most often for defining XML documents, however you can also call the Builder::XmlMarkup.new method within any other methods and generate XML markup inline. Using the same example, this is the execution using Builder::XmlMarkup instead of content_tag

def render_user_status
  xhtml = Builder::XmlMarkup.new :target => out=(''), :indent => 2
  xhtml.div(:id => "user_nav") do |x|
    if user_signed_in?
      x << "Signed in as #{current_user.email}. Not you? "
      x << link_to("Sign out", destroy_user_session_path)
    else
      x << link_to("Sign up", new_user_registration_path)
      x << " or "
      x << link_to("Sign in", new_user_session_path)
    end
  end
end

As you can see it’s much more readable than the previous example

However each to their own, but I think personally the Builder gem is incredibly useful for creating XML style markup instead of using Rails’ built in helpers to generate HTML. Give it a go, you might be pleasantly surprised!