Ruby on Rails ActiveRecord Validations Conditional validation
Example
Sometimes you may need to validate record only under certain conditions.
class User < ApplicationRecord
validates :name, presence: true, if: :admin?
def admin?
conditional here that returns boolean value
end
end
If you conditional is really small, you can use a Proc:
class User < ApplicationRecord
validates :first_name, presence: true, if: Proc.new { |user| user.last_name.blank? }
end
For negative conditional you can use unless:
class User < ApplicationRecord
validates :first_name, presence: true, unless: Proc.new { |user| user.last_name.present? }
end
You can also pass a string, which will be executed via instance_eval:
class User < ApplicationRecord
validates :first_name, presence: true, if: 'last_name.blank?'
end
