Question

Is there any way to eager load a named_scope from an association?

I have my Article model:

class Article < ActiveRecord::Base   has_many :comments end 

and my Comment model:

class Comment < ActiveRecord::Base   belongs_to :article    named_scope :approved, :conditions => { :approved => true }   named_scope :unapproved, :conditions => { :approved => false } end 

I could eager load all comments for an article with:

@article = Article.find(params[:id], :include => :comments) 

How can I do the same, but only for approved comments?

Answer 1

It is not built-in to rails at this time, but Ryan Daigle created a plugin called utility_scopes that adds a with() scope so you can do:

Article.approved.with(:comments) 

Blog Post: http://ryandaigle.com/articles/2008/8/20/named-scope-it-s-not-just-for-conditions-ya-know Github Repo: http://github.com/yfactorial/utility_scopes

[Updated per comment]

My bad. I didn’t read well enough. I don’t think there’s anything that will let you call on an association named_scope like that. The closest thing I can think of would be creating a named_scope on Article:

class Article < ActiveRecord::Base    named_scope :with_approved_comments, {:include => :comments, :conditions => ['comments.approved = ?', true]} end 

Hope this helps.