ruby on rails - Using Parameter in Validation -

i have validation needs apply per project user in. solution came call model method controller:

controller:

client.validate_uniq_record(params[:project_id]) 

model:

def self.validate_uniq_record(proj_id)     validates_uniqueness_of :item, scope: :price, conditions: -> {where(project_id: proj_id)} end 

from reading other questions, looks passing param model big nono: how access params in callback of rails model? not figure out how through virtual attribute either.

how validates_uniqueness_of current project user in?

note, client object has project_id column fk