ruby on rails - nested validation - model -

i have 2 linked models (simplified) :

ad :

class ad < activerecord::base has_many :propositions validates :pricemin validates :pricemax ... 

proposition :

class proposition < activerecord::base belongs_to :ad attr_accessible :price_proposition ... 

i'm trying add restriction price_proposition (in "proposition" model) between "pricemin" , "pricemax".

how ?

thanks help

client side validation via javascript 1 way go. if want server side validation, can this:

class proposition < activerecord::base    belongs_to :ad   attr_accessible :price_proposition    validate :price_proposition_in_range    def price_proposition_in_range     pricemin = self.ad.pricemin     pricemax = self.ad.pricemax     if self.price_proposition < pricemin || self.price_proposition > pricemax       errors.add(:price_proposition, "must between #{pricemin} , #{pricemax}")     end   end    .   .   . end 

and of course, can add further checks in method, depending on whether want allow blank or not etc etc.