randomor/rails3_ac_enum

Make the new ActiveRecord::Base#enum in Rails4 also works for Rails3

Rails3AcEnum

The ActiveRecord::Base#enum is original created by DHH in Rails 4 for declaring enum attributes where the values map to integers in the database, but can be queried by name.

If you want to use it in your Rails3 application. Please go and check out this gem.

Installation

Add this line to your application's Gemfile:

gem 'rails3_ac_enum'

And then execute:

$ bundle

Or install it yourself as:

$ gem install rails3_ac_enum

Usage

Declare an enum attribute where the values map to integers in the database, but can be queried by name. Example:

class Conversation < ActiveRecord::Base
  enum status: [ :active, :archived ]
end

Conversation::STATUS # => { active: 0, archived: 1 }

# conversation.update! status: 0
conversation.active!
conversation.active? # => true
conversation.status  # => :active

# conversation.update! status: 1
conversation.archived!
conversation.archived? # => true
conversation.status    # => :archived

# conversation.update! status: 1
conversation.status = :archived

You can set the default value from the database declaration, like:

create_table :conversations do |t|
  t.column :status, :integer, default: 0
end

Good practice is to let the first declared status be the default.

Finally, it's also possible to explicitly map the relation between attribute and database integer:

class Conversation < ActiveRecord::Base
  enum status: { active: 0, archived: 1 }
end

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request