archive.rb

def archives filter = "", tag = nil
  entries = ! self.articles.empty??
    self.articles.select do |a|
      filter !~ /^\d{4}/ || File.basename(a) =~ /^#{filter}/
    end.reverse.map do |article|
      Article.new article, @config
    end : []

  if tag.nil?
    { :archives => Archives.new(entries, @config) }
  else 
    tagged = entries.select do |article|
      article_tag = article.tags
      article_tag && article.tags.gsub(/\s+/, "").split(",").include?(tag)
    end 
    { :tag => tag, :archives => tagged } if tagged.size > 0 
  end
end