About Ackbar

Ackbar is an adapter for ActiveRecord (the Rails ORM layer) to the KirbyBase pure-ruby plain-text DBMS. Because KirbyBase does not support SQL, joins or transactions, this is not a 100% fit. There are some changes to the ActiveRecord interface (see below), but it may still be useful in some cases.

URIs

Ackbar: ackbar.rubyforge.org

KirbyBase: www.netpromi.com/kirbybase_ruby.html

Rails: www.rubyonrails.com

Pimki: pimki.rubyforge.org

Goals

Ackbar’s project goals, in order of importance, are:

1. Support Pimki with a pure-ruby, cross-platform hassle-less install DBMS
2. An exercise for me to learn ActiveRecord inside out
3. Support other "shrink-wrapped" Rails projects with similar needs

As can be seen, the main reason I need Ackbar is so I distribute Pimki across multiple platforms without requiring non-Ruby 3rd party libraries. KirbyBase will work wherever Ruby works, and so will Pimki. That alleviates the need to repackage other bits, end users will not have to install extra software, I have full control on the storage, the storage is in plain text. Just what I need to "shrink wrap" a Rails project for end-user distribution.

What’s Covered

Ackbar currently passes through a small bootstrap test suite, and through about 80% of the ActiveRecord test suite. I will never pass 100% of the tests because KirbyBase does not support all required functionality.

Ackbar includes a SQL fragment translator, so that simple cross-database code should be maintainable. For example the following will work as expected,

  Book.find :all, :conditions => "name = 'Pickaxe'"
  Book.find :all, :conditions => ["name = ?", 'Pickaxe']

Additionally, you can also provide blocks:

  Book.find :all, :conditions => lambda{|rec| rec.name == 'Pickaxe'}

or even:

  Book.find(:all) {|rec| rec.name == 'Pickaxe'}

Most of these changes are around the find method, bit some apply to update and associations. Basic SQL translation should work the same, but you can always provide custom code to be used. See the CHANGELOG and the tests for examples.

What’s Not Covered

• Transactions
• Joins, and therefore Eager Associations
• Mixins
• Other plugins

On the todo list is support for mixins. It might even be possible to rig something to simulate joins and eager associations, but that is for a later stage. Transactions will obviously only be supported once they are supported by KirbyBase.

Additionally, there are numerous little changes to the standard behaviour. See the CHANGELOG and the tests for more details. These may cause little heart attacks if you expect a standard SQL database.

It is also worth noting that other plugins that write SQL will not work. You will need to get a copy of them to your /vendors dir and modify the relevant parts.

Installation

Simply:

  gem install ackbar

or download the zip file from rubyforge.org/projects/ackbar and just stick kirbybase_adapter.rb in the Rails lib dir.

You will then need to add

  require 'kirbybase_adapter'

in the config/environment.rb file of your project.

If you plan on multi-database development / deployment, you must require the adapter only if necessary:

  require 'kirbybase_adapter' if ActiveRecord::Base.configurations[RAILS_ENV]['adapter'] == 'kirbybase'

This is because Ackbar overrides certain methods in ActiveRecord::Base and others. These methods translate the standard SQL generation to method calls on KirbyBase, and obviously should not be overridden for regular DBs.

Now we go back to our regular scheduled programming, consisting of mostly silence as I actually code more than I write about it. More updates *soon* :-)