Command line utility to interrogate models
I’ve started working at a really great company recently (a little ass kissing never hurts), and one of the projects I’m working on has some pretty hairy interrelated models on the back end.
As both an exercise in meta-programming, and to help me get a handle on the code I’m working with, I’ve written a little command line script that dumps all kinds of information about a model (or about the general hierarchy of all the models).
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.
Leave a comment...