Question

I have something like this my user model

class User < ActiveRecord::Base 

has_many :received_msgs, class_name:"Message", foreign_key: "recipient_id", :conditions =>['owner_id = ?', self.id]
has_many :sent_msgs, class_name: "Message", foreign_key: "sender_id", :conditions =>['owner_id = ?', self.id]

where I want the owner_id to almost act as a secondary foreign key since each message is duplicated for independent deletion.

However, I’m getting an error saying id isn’t defined for the object. How do I access self.id in this case? Or is there a better way of doing this?

Thanks

Answer 1

Are you sure you don’t just want the foreign_key to be owner_id? That way, you won’t need that conditions array at all.

Anyhow, the reason you can’t access self.id in the associations definition is because of what scope the code is evaluated in. The associations are evaluated when loading the class, and not when actually calling the #received_msgs method on a User instance.

I believe you could access the self.id of the instance by wrapping the conditions array in a lambda. That way it will not be evaluated until you call it.