Sorting forum topics by the most recent replies

I have built a simple forum but am having difficult getting the topics
to display in the order of their latest reply.

The associations are as follows:

class Forum < ActiveRecord::Base
has_many :topics, :order => “sticky DESC, created_at DESC”
has_many :replies, :through => :topics

class Topic < ActiveRecord::Base
belongs_to :forum
has_many :replies, :order => “created_at”, :dependent => :destroy

class Reply < ActiveRecord::Base
belongs_to :topic

And in my controller I am calling @topics = @forum.topics

What I would like to do is sort the topics by the created_at of their
most recent posts.

Any advice appreciated.



On 3/23/2010 2:56 PM, DanC wrote:

belongs_to :forum
Any advice appreciated.

Add a last_reply_at field to Topic. Add a after_save to Reply that
updates last_reply_at. When you find all topics sort by last_reply_at.



Jack C.
[email protected]