Rails strong parameters incremental addition -

does know, if strong_parameters gem, can incrementally add attributes below:

def user_params   params[:user].permit(:name, :email)    if current_user.admin?     params[:user].permit(:is_admin)   end end 

here incrementally asking code permit :is_admin parameter if current user admin. shouldn't add permitted list of parameters (:name , :email)?

they way have done put params in class strong-parameters railscast..

this way have this

 class permittedparams < struct.new(:params,:admin)     def administrator_attributes        allowed = [:email, :name, :password, :password_confirmation, :password_digest]     if admin.has_any_role? :realm_admin, :system_admin       allowed << :active << :roles     end     allowed    end     .... other models ....        def method_missing(method,*args,&block)     attributes_name = method.to_s + '_attributes'     if respond_to? attributes_name, false       params.require(method).send(:permit, *method(attributes_name).call)     else       super     end   end  end 

then in controller call @administrator.update_attributes(permitted_params.administrator)

as array can build array, , use * pass permit.