In some instances you might create a class method that essentially aliases a named scope or represents a named scope procedure. Ex:

  class User
    def self.teenager
      age_gte(13).age_lte(19)
    end
  end

This is obviously a very basic example, but notice how we are utilizing already existing named scopes so that we do not have to repeat ourself. This method makes a lot more sense when you are dealing with complicated named scope.

There is a problem though. What if you want to use this in your controller‘s via the ‘search’ method:

  User.search(:teenager => true)

You would expect that to work, but how does Searchlogic::Search tell the difference between your ‘teenager’ method and the ‘destroy_all’ method. It can‘t, there is no way to tell unless we actually call the method, which we obviously can not do.

The being said, we need a way to tell searchlogic that this is method is safe. Here‘s how you do that:

  User.alias_scope :teenager, lambda { age_gte(13).age_lte(19) }

This feels better, it feels like our other scopes, and it provides a way to tell Searchlogic that this is a safe method.

Alias for alias_scope