I wanted to be able to pretty print ActiveRecord objects, and do so in a way that’s a little bit more involved than what pp gives you:

module ActiveRecordPrettyPrint

  def pprint(ar, maxdepth=1)
    pp_helper(ar, "", 0, [], maxdepth - 1)
  end

  private
  def pp_helper(ar, buf, level, seen, maxdepth)
    if level > maxdepth || seen.member?(ar)
      buf << (" " * level) + "#{ar}n"
      return buf
    end

    seen << ar

    reflections = ar.class.reflections
    rcolumns = reflections.collect { |k, v| v.primary_key_name }

    buf << "#{ar.class}:n"
    ar.attributes.keys.reject { |k| rcolumns.member? k }.each do |k|
      buf << (" " * level) + "#{k}  =>  " + ar.send(k).to_s + "n"
    end

    reflections.keys.each do |k|

      buf << (" " * level) + k.to_s + " =>  "
      res = ar.send(k)
      if res.nil?
        buf << "[nil]n"
      elsif res.class == Array
        res.each do |o|
          pp_helper(o, buf, level + 1, seen, maxdepth)
        end
      else
        pp_helper(res, buf, level + 1, seen, maxdepth)
        buf << "n"
      end
    end

    return buf
  end

end

I suspect I’ll fix it up more as I go along, but this is the basic idea… Be careful with maxdepth, though, or else you risk hitting the database too much.