Rails: validates_uniqueness_of with conditions not working as expected
activerecord, ruby-on-rails, validation
Solution
You can use the `scope` and `if` modifiers in conjunction for this:
scope :active, where(:active => true)
validates :name, :uniqueness => {:message => 'That name is in use', :if => :active?, :scope => :active}
This will cause only items that are active to trigger the validation, and the validation will consider uniqueness only among items that are active.
I have confirmed that this works in Rails 3 and 4.
Problem
I have a model that uses an 'active' flag to soft-delete items instead of destroying them. The model has a 'name' property, which must be unique among active items. I was trying to use the `conditions` modifier with `validates_uniqueness_of`, but it still seems to be checking for uniqueness across both active and inactive items. What am I doing wrong? ``` class Foo < ActiveRecord::Base attr_accessible :name, :active validates_uniqueness_of :name, conditions: -> { where(active:true) } end ```