Nanoc helper to list articles related to the current item

related_articles_help.rb

def related_articles
  articles = []
  if item[:tags] != nil
    # Iterate over the all the tags and collect the articles
    # with the same tags. If the article shares more than one tag then
    # weight the article.
    @item[:tags].each do | tag|
      @items.each do |item|
        if item[:tags] != nil and item[:tags].include? tag
          article = (articles.select { |a| a[:item] == item }).first
          if article == nil
            article = { :item => item }
            articles << article
          end
          article[:count] = (article[:count] || 0) + 1
        end
      end
    end
    # Sort the articles list by the number of tags they share
    articles.sort! { |a, b| b[:count] <=> a[:count] }
    # Ignore any items which don't share more than two tags
    articles.reject! { |a| a[:count] < 2 }
    # Only return the items
    articles.collect! { |a| a[:item] }  
  end
  articles
end

Thank you for this. Really useful. As a side note, if one is only interested in the articles that are different from the current one, instead of iterating on all items (@items.each do |item|) it is enough to iterate on (@items - [item]).each do |item|.