gistfile1.erb

before: 

<%= if profile.has_experience? && profile.experience_public? %>
  <p><strong>Experience:</strong> <%= user_profile.experience %></p>
<% end %>

//after

<h2><%= user_profile.full_name %></h2>
<%= user_profile.bio_html %>
<% user_profile.with_experience do %>
  <p><strong>Experience:</strong> <%= user_profile.experience %></p>
<% end %>
<% user_profile.with_hobbies do %>
  <p><strong>Hobbies:<strong> <%= user_profile.hobbies %></p>
<% end %>

class ProfilePresenter < ::Presenter
  def with_experience(&block)
    if profile.has_experience? && profile.experience_public?
      block.call(view)
    end
  end
end

from http://www.saturnflyer.com/blog/jim/2013/10/21/how-to-make-your-code-imply-responsibilities/