From: bdarcus@...
Date: 2005-06-26T23:30:39+09:00
Subject: grouping/sorting [newbie question]

I'm trying to do something fairly simple that I understand how to do in
XSLT, but not in Ruby.

I have a list of film recommendations, with comments, in a yaml file
that looks like this:

  -
    title: Lost in translation
    setting: Tokyo
    comments: Some comments..
  -
    title: Chungking Express
    setting: Hong Kong
    comments: >
        Some comments.

Since a film may have more than one entry, I want to create a list that
groups the comments by film.  So I'd like output like:

Some Film
=======
Comment 1.

Comment 2.

However, while I figured out how to sort the list correctly, I don't
really understand how to do the grouping. Could someone please explain?

Current code:

require 'yaml'

films = YAML::load(File.open("film.yaml"))

sorted = films.sort_by{|film| film["title"]}

sorted.each do |item|
  # I want to put the title for a group here,
  #  then list the comments.
  if item["comments"] : puts item["comments"]
  else ''
  end
end

Bruce