If you run the script with no arguments, it prints a little tree showing the object hierarchy:
$ show_model ActionMailer::Base Notifier ActiveRecord::Base Tag Posting Comment Entry Preferences User Group
Note that, in this example, comments and entries are subclasses of Postings (using single table inheritance).
More useful, though, is getting a quick reference on what class methods, instance methods, associations, and table columns a model has:
User < ActiveRecord::Base Class Methods: login Instance Methods: has_access_to? password_confirmation password_confirmation= posts_about tags Associations: has_many Comments has_many Entries has_many Groups has_many Postings has_many Postings as non_comment_postings has_one Preferences as preferences DB Columns: active (boolean) admin (boolean) birth_date (date) created_on (datetime) email (string) first_name (string) id (integer) last_login (datetime) last_name (string) password (string) prev_login (datetime) updated_on (datetime)
Anyways, I thought I’d post this in case it helps anyone else. You can download it here. Should also say that it currently assumes that you’re in the base RAILS_DIR directory.
Next up is a rails2dot that doesn’t suck.