Pass arguments in scope

Question

Can someone provide an example on how to use

scope

and parameters?

For example:

class Permission < ActiveRecord         


        

Answer 1

new syntax (ruby 1.9+), that will prevent errors even if you don't supply the user -

scope :default_permissions_for, ->(user = nil) { ... }

Answer 2

Use lambda scopes:

scope :default_permissions_for, lambda{|user| { :conditions => { :user_id => user.id, :is_default => true } }

Be careful because not passing a parameter to a lambda when it expects one will raise an exception.