richard_gill

Simple Versioning for DataMapper Models

richard_gill tracks changes of your objects over time by storing serialized hashes of changesets.

This can be used to implement version control (by traversing up the changeset chain) or to create a log of activity.

Usage

Watch SomeModel:

class SomeModel
  is :watched

See is_watched in richard_gill.rb for options.

Working with versions

# Revert an object to a previous version
@some_object.revert

# Revert an object to two versions prior
@some_object.revert(2) 

# Show all object versions
@some_object.versions

Note that calling revert does not make any changes to the object, and you must #save the object after calling revert. To do this in one step use object.revert!.

Storing the user with the changeset

It's nice to know WHO made the changes on the object. By default, RichardGill stores this as updated_by. This can be explicitly set when saving a version or ... instead of passing around the user, create a User::current method!

class User
  class << self
    def current
      Thread.current[:user]
    end

    def current=(user)
      raise(ArgumentError,
        "Invalid user. Expected an object of class 'User', got #{user.inspect}") unless user.is_a?(User)
      Thread.current[:user] = user
    end
  end
end

If Richard Gill sees that the "User" class responds to a #current method, it will use that instead of requiring an explicit updated_by to be passed in during object updates.

Erata

Named for the character of Special Agent Richard Gill from the best movie to ever grace the silver screen, Hackers.

"I'm watching yoooou." - Special Agent Richard Gill

Note on Patches/Pull Requests

• Fork the project.
• Make your feature addition or bug fix.
• Add tests for it. This is important so I don't break it in a future version unintentionally.
• Commit, do not mess with rakefile, version, or history. (if you want to have your own version, that is fine but bump version in a commit by itself I can ignore when I pull)
• Send me a pull request. Bonus points for topic branches.

Copyright

Copyright (c) 2010 Asher Van Brunt. See LICENSE for details.