Conditional Class Selectors in Haml
You can assign a class selector to a tag in HAML like so:
%div.active
You can conditionally assign a class selector in a concise manner like so:
%div{ class: ( "active" if @thing.active? ) }
You can do multiple conditional class selectors with array syntax:
%div{ class: [ ("active" if @thing.active?), ("highlight" if @thing.important?) ] }