Activerecord has_many custom method

Hi,
I’m trying to create this method:

has_many :cars do

Car.where(color: ‘red’).all

end

I’m using a class without Activerecord and outside rails:

module API

class User < Base

include ActiveRecord::Associations

has_many :cars do

Car.where(color: ‘red’).all

end

end

end

When I run:

undefined method `dangerous_attribute_method?’

How can I use a has_many and create my own implementation ?

Thanks.

Have a look at rails scope. I’m pretty sure this is the functionality you are looking for.
http://guides.rubyonrails.org/active_record_querying.html#scopes

Basically, you define your association, then define a scope to retrieve the records how you’d like to.