ruby on rails - How do I define instance abilities in cancan without defining class abilities? -

ruby on rails - How do I define instance abilities in cancan without defining class abilities? -

how define instance abilities in cancan without defining class abilities?

i want allow :manage action particular course instances, not course class.

# ability.rb can :manage, course of study |course| # check if user helper course of study courserole.get_role(user, course) == "helper" end

this works fine instance variables:

# some_view.rb can? :manage, @course # checks instance see if :manage allowed

but if this:

# some_view.rb can? :manage, course of study

it returns true, bad.

some context:

class user < activerecord::base has_many :course_roles has_many :courses, :through => :course_roles ... class courseroles < activerecord::base belongs_to :user belongs_to :course ... class courses < activerecord::base has_many :course_roles has_many :users, :through => :course_roles

instead of can? :manage, course, can utilize can? :manage, course.new , sure new course of study objects fail block passed in ability.rb

ruby-on-rails ruby cancan