MaskedAttribute

Add methods for working with a masked attribute in models.

Usage

Add field to database

Create the backing field. It should be appended with _mask. To add roles to User, the field would be role_mask. The field must be an integer and should be default: 0, null: false.

Example migration:

bin/rails generate migration add_roles_to_user role_mask:integer

Modify the migration to set the default to 0, and disallow NULLs.

class AddRolesToUsers < ActiveRecord::Migration[7.0]
  def change
    add_column :users, :role_mask, :integer, null: false, default: 0
  end
end

bin/rails db:migrate

Include in your model

class User
  include MaskedAttribute

  masked_attribute :roles, %i[admin sysadmin]
end

The masked_attribute takes two arguments, attribute_name and masks.

attribute_name is the name for the masked attribute. For example a name of :roles will create methods for the role_mask backing attribute.

masks is an array of symbols for the mask values. Order matters. You can change the values of the masks, but if you change the order, you'll need to migrate existing data.

masked_attribute will add methods, scopes, and contants to User for working with roles.

User::ROLES = masks
User::INDEXED_ROLES = {mask_value => mask, ...}

# Add attr_writer for the ATTRIBUTE_NAME. This should always be called with the full array of roles.
def roles= [array_of_masks]

# Add attr_reader for the ATTRIBUTE_NAME
def roles -> [array_of_masks]

# Add a scope with_ATTRIBUTE_NAME, which returns records that match ALL given masks
scope with_roles(*masks)

# Add a scope with_any_ATTRIBUTE_NAME, which returns records that match ANY given masks
scope with_any_roles(*masks)

# Add scopes for each MASK, to return records with the MASK in the name of the method
scope admins()
scope sysadmins()

# Add MASK? methods. Returns true if the mask is set
def admin?
def sysadmin?

# Add add_MASK! methods. Updates the backing field with the MASK value in the name.
def add_admin!
def add_sysadmin!

# Add remove_MASK! methods. Updates the backing field with the MASK value in the name.
def remove_admin!
def remove_sysadmin!

# Add a MASK from the mask_attribute_name
def add_role(mask)

# Remove a MASK from the mask_attribute_name
def remove_role(mask)

Installation

Add this line to your application's Gemfile:

gem "masked_attribute"

And then execute:

$ bundle

Or install it yourself as:

$ gem install masked_attribute

Contributing

Contribution directions go here.

License

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