Scopes in Rails 4

Today we will see a quick tip about scopes in Rails 4.

You may have been used to this kind of scopes with Rails 3 :

 scope :active, where(active: true)

But in Rails 4, you need to give it a callable object like a Proc or a Lambda :

 scope :active, -> { where(active: true) } 

You can also pass it a parameter :

 scope :things, -> (type) { where(type: type)}    

You can still define class method if you prefer :

 self.active
      where(active: true)
 end

Whatever way you chose, always keep in mind that scopes have to be chainable. Therefore, they need to return an ActiveRecord::Relation object.