counter_cache through, is this possible?

rubyonrails-talk
1

Say I have A which has many B which has many C, ideally I want the quickest way to get the count of C for A, a counter cache through an association with B would do - but I don't think that exists. Any ideas?

2

No the counter_cache is on the belongs_to and if I try adding through on the belongs to then it whinges, e.g. on C:

belongs_to :a, through => :b, :counter_cache => true

I get the error undefined local variable or method 'through'

-D

3

What I've ended up doing is the following

class C < ActiveRecord::Base     belongs_to :B

    after_create :increment_A_counter_cache     after_destroy :decrement_A_counter_cache

    private

    def increment_A_counter_cache         A.increment_counter( 'c_count', self.B.A.id )     end

    def decrement_A_counter_cache         A.decrement_counter( 'c_count', self.B.A.id )     end end

It seems to work, I was just wondering if there was a way to do it through the framework.

-D