attr_effective

Effective values for rails model attributes using a default value from a model method or I18n string

Add this line to your application's Gemfile:

gem 'attr_effective'

And then execute:

$ bundle

Or install it yourself as:

$ gem install attr_effective

Create an initializer and extend ActiveRecord with the concern

initializers/attr_effective.rb:

ActiveRecord::Base.send :include, AttrEffective

You are now ready to use the class attribute:

class MyModel
  attr_accessible :value
  attr_effective :value

  # If this method does not exist then I18n translate is called for the following key:
  # activerecord.defaults.my_model.value
  def value_default
    "This default is used when value is nil"
  end
end

MyModel.new.value_default 
=> "This default is used when value is nil"

MyModel.new.value_effective 
=> "This default is used when value is nil"

my_model = MyModel.new
my_model.value = "My value"
my_model.value_effective
=> "My value"

en:
  activerecord:
    defaults:
      my_model:
        value: A default value from I18n when model attribute does not exist

If your default locale strings frequently refer to similar or common named parameters then these can be shared with the I18n translation lookups by creating an instance method 'attr_effective_default_opts'

class MyModel
  attr_accessible :value
  attr_effective :value

  def attr_effective_default_opts
    {
      company_name: "Acme"
    }
  end
end

en:
  activerecord:
    defaults:
      my_model:
        value: Your company name is %{company_name}

MyModel.new.value_default
=> "Your company name is Acme" 

• activesupport (ActiveSupport::Concern)
• rails_i18n

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/attr_effective. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

The gem is available as open source under the terms of the MIT License.