How to recursively count threads belonging to a chain of forums

rubyonrails-talk
1

class Forum::Forum < ActiveRecord::Base   belongs_to :parent_forum, :class_name => "Forum"   has_many :sub_forums, :class_name => "Forum", :foreign_key => :parent_id   has_many :threads

  def count_threads     threads.count   end end

Hi I am trying to count all the threads that belong to a forum right though the chain. Currently it counts the threads that belong to the forum you're on, so if you're on forum id 1 it will count threads that belong to forum id 1 only, however forum id 1 also has sub_forums such as forum id 4 which also has a sub_forum with a id of 8 and this could go on forever.

I would really appreciate some help here, I have grand plans to build my site in rails instead of zend framework but a few little snags are keeping me stuck sometimes.

2

Hi I am trying to count all the threads that belong to a forum right though the chain.

class Forum::Forum < ActiveRecord::Base belongs_to :parent_forum, :class_name => "Forum" has_many :sub_forums, :class_name => "Forum", :foreign_key => :parent_id has_many :threads

def count\_threads
  sub\_forums\.inject\(threads\.count\) \{ |memo, sub\_forum| memo \+=

sub_forum.count_threads }     end

end

That should recurse through all the sub-forums... make sure you don't nest an upper forum in one of the children because you'll get a stack overflow :slight_smile:

3

Cheers was a great help