trustieforge/lib/tasks/hjq_test.rake

namespace :hjq do
  namespace :news do
    desc "news order"
    task :users => :environment do
      a = []
      # news = News.where("course_id =?", 122)
      course.news.each do |new|
        unless new.comments.blank?
          latest_comment = new.comments.sort! { |a,b| a.created_on <=> b.created_on}.last
        end
        a << latest_comment
      end
      comments = a.map(&:commented_id).detect{|a.b| a.created_on <=> b.created_on}
     # comments = a.sort!{|a.b| a.created_on <=> b.created_on}
      news = News.where("id in (?)", comments)
    end
  end
end