Use query attribute

Bad Smell

<% if @user.login.blank? %>
  <%= link_to 'login', new_session_path %>
<% end %>

<% if @user.login.present? %>
  <%= @user.login %>
<% end %>

It's not bad, but rails provides a cleaner way, we should use query attributes to make codes simpler

Refactor

<% unless @user.login? %>
  <%= link_to 'login', new_session_path %>
<% end %>

<% if @user.login? %>
  <%= @user.login %>
<% end %>

As you seen, the query attribute is almost the same as the present? method call on attribute, or the opposite of blank? method call. Each attribute of ActiveRecord's model has a query method, so you don't need to use the present? or blank? for ActiveRecord's attributes.