Acts_as_versioned Rails Plugin

Versioning models with the acts_as_versioned plugin

cd rails/app
./script/plugin install git://github.com/technoweenie/acts_as_versioned.git
./script/generate model post title:string body:text

In your model

class Post < ActiveRecord::Base
  acts_as_versioned
end

In db/migrate/****_create_posts.rb

  def self.up
    create_table :posts do |t|
      t.string :title
      t.text :body
      t.timestamps
    end
    Post.create_versioned_table
  end

  def self.down
    drop_table :posts
    Post.drop_versioned_table
  end

Migrate your db

rake db:migrate

Usage

p = Post.create :body => "hello world"
p.body = "HELLO WORLD"
p.save

p.versions.size
p.versions.last
p.revert_to(p.versions.first)
p.body # => hello world

*Quick Note If you want to revert to an older version in a controller or something, don't do

@post = @post.revert_to(2)

Revert_to method will return a TrueClass, Boolean type. Instead use

@post.revert_to(2)

This method will update the attributes for you and when you call them you'll get that version.

More information is available here http://ar-versioned.rubyforge.org/ and http://www.urbanhonking.com/ideasfordozens/archives/2006/02/learns_to_use_a_1.html

Install MySQLdb for Python on Mac OS X

I don’t do much python development. I really like the language and there are a lot of great software projects out there for it. Tornado, for example, is a fast non-blocking web server in python, just open sourced by Facebook that is the engine behind FriendFeed.com.

I downloaded the source, available at, http://tornadoweb.org, and started playing around. It comes with a database wrapper for mysql. Using “easy_install”, I suppose the python equivalent to gems, it goes something like this…

sudo easy_install MySQLdb-python

Nope at least not on OS X. Time to do it the hard way. Luckily not too hard. It just can’t find the right path to mysql_config. Sound familiar? http://seanbehan.com/databases/install-do_mysql-ruby-gem-on-mac-os-x/

Anyway, here are the commands that worked for me…

wget http://dl.sourceforge.net/sourceforge/mysql-python/MySQL-python-1.2.3c1.tar.gz
tar xzvf MySQL-python-1.2.3c1.tar.gz
cd MySQL-python-1.2.3c1

In the setup_posix.py file change

mysql_config.path = "mysql_config"

to

mysql_config.path = "/opt/local/lib/mysql5/bin/mysql_config"

Next install it with these commands

 python setup.py clean
 python setup.py build
 sudo python setup.py install

That should do it.

Regular Expression for finding absolute URLs

Regular Expression for finding absolute URLs in a bunch of text… like a log file.

/(http:(.*?)\s)/

Non Standard Port Number with SSH and Git

Here is an example using the port 4567 to connect with over ssh and git

ssh remote add origin ssh://sean@seanbehan.com:4567/path/to/git
git push origin master