AttributeAccessControllable

This gem allows you to control write access at the attribute level, on a per-instance basis. For example, let's say you had a model Person that has an attribute, birthday, which, for security purposes, once this attribute is set, cannot be changed again (except, perhaps by an administrator with extraordinary privileges). You would want any attempts to change this value to raise a validation error.

e.g.

alice = Person.create(:birthday => '12/12/12')
=> <Person...>
alice.birthday= '1/1/01'
=> '1/1/01'
alice.save!
=> ActiveRecord::RecordInvalid ... "birthday is invalid: birthday is read_only"

Installation

Add this line to your application's Gemfile:

gem 'attribute_access_controllable'

And then execute:

$ bundle

Or install it yourself as:

$ gem install attribute_access_controllable

Usage

Generate a migration for your class

$ rails generate attribute_access Person
$ rake db:migrate

In your model, add the following:

class Person < ActiveRecord::Base
  include AttributeAccessControllable

Add hooks to mark attributes as read_only:

before_save :mark_birthday_read_only

private

  def mark_birthday_read_only
    attr_read_only(:birthday)
  end

If, in the future, you need by-pass the validations, pass :skip_read_only => true to the instance's save or save! methods.

RSpec support

Adding this to your model spec will exercise the feature.

require 'attribute_access_controllable/spec_support'

describe Person do
  it_should_behave_like "it has AttributeAccessControllable", :test_column
end

Contributing

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