HasDefault
Specify a "default" instance that is to be returned for an ActiveRecord model when Model.default is called.
Installation
Install the has_default gem
gem install bradgessler-has_default
Then configure in rails
config.gem 'bradgessler-has_default',
:lib => 'has_default',
:source => 'http://gems.github.com'
For whatever model you need to set a default for, run the a similar migration
class AddDefaultsToModels < ActiveRecord::Migration
def self.up
change_table :plans do |t|
t.boolean :default
end
add_index :plans, :default, :unique => true
end
def self.down
remove_index :plans, :default
change_table :plans do |t|
t.remove :default
end
end
end
Example
class Plan
has_many :accounts
has_default
end
class Account
belongs_to :plan
before_validate :set_default_plan, :unless => Proc.new{|a| a.plan.present? }
protected
def set_default_plan
self.plan = Plan.default
end
end
Plan.create(:name => 'Free', :default => true)
Plan.create(:name => 'Medium')
Plan.create(:name => 'High')
Account.new.plan.name # => 'Free'
Plan.find_by_name('High').update_attribute(:default, true)
Account.new.plan.name # => 'High'
License
Copyright (c) 2009 Brad Gessler, released under the MIT license
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.