Ruby on Rails - conditional validation in ruby on rails - ruby on rails tutorial - rails guides - rails tutorial - ruby rails
Sometimes we 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
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- If we conditional is really small,
- We can use a Proc:
class User < ApplicationRecord
validates :first_name, presence: true, if: Proc.new { |user| user.last_name.blank? }
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Negative conditional we can use unless:
class User < ApplicationRecord
validates :first_name, presence: true, unless: Proc.new { |user| user.last_name.present? }
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we 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