How to write if-condition in Haml?

Question

How to write if and if-else statements in Haml for a Ruby on Rails application?

Answer 1

If you want to put condition inside your tag

%section{:class => "#{'new-class' if controller.action_name == 'index'}"}

UPDATE

Here is another variation

%nav(class="navbar"){class: content_for?(:navbar_class) ? yield(:navbar_class) : nil}