Polymorphic associations with ownership

rubyonrails-talk
1

Hi everyone,

I'm sure the answer is out there and quite simple, but I haven't been able to find it.

Suppose I have the following classes with polymorphic associations:

class Comment < ActiveRecord::Base   belongs_to :commentable, :polymorphic => true end

class Camera < ActiveRecord::Base   has_many :comments, :as => :commentable end

class Computer < ActiveRecord::Base   has_many :comments, :as => :commentable end

class Book < ActiveRecord::Base   has_many :comments, :as => :commentable end

How do I also make the Comment class belong_to a User class? Would the User class be parallel to the Camera, Computer, and Book classes? For example, would I define the relationship between User and Comment as such:

class User < ActiveRecord::Base   has_many :comments, :as => :commentable end

And how would I go about referencing the comments through the User-

Camera/Computer/Book association? Would it be as such?

@user.computers.comments.empty? # For example

Thanks in advance!

Mike

2

Just in case this wasn't clear, I would like every comment to belong to a user and only be editable by that user, but be associated with a product type (Camera, Book, etc.). This is why I doubt the simple class definition I outlined below would suffice.

Best,

Mike

3

Sounds like you could just add a “belongs_to :user” to the Comment class.

But since you already have “comments” on the user, you’ll need to give the reverse association another name. Perhaps “comments_owned”

So add “has_many :comments_owned, :class_name => Comment” to User.

4

Thanks, Tim

Actually, and I haven't fully tested this out yet, I think it's simpler than that. Currently, I hvae the following:

class Comment < ActiveRecord::Base   belongs_to :user   belongs_to :commentable, polymorphic => true ... end

and that seems to be working. I have another issue now that I'll outline in a subsequent email.

Best,

Mike