enum_field

Enables Active Record attributes to point to enum like objects, by saving in your database only an integer ID.

Install

gem 'galetahub-enum_field', require: 'enum_field'

Features

Allows creation of Classes with enum like behaviour.
Allows any number of members and methods in the enum classes.
Allows an integer id to be used in your database columns to link to the enum members (user.role_id)
Enables higher abstraction interaction with AR attributes:
- user.role = Role.admin
- if user.role.can_edit?
Saves in your AR tables, only an integer id pointing to the enumeration member.

Synopsis

When in an Active Record class, you have an attribute like role, state or country you have several options.

You can create a roles, states or countries table, and dump there all possible values.
You can use a string to identify, for instance, the role.
You can use an id to identify the role.

If you are not comfortable with any of this options, maybe enum_field is an answer for you.

Basic usage

Define rules:

class Role
  include EnumField::DefineEnum

  define_enum do
    member :admin
    member :manager
    member :employee
  end
end

class User < ActiveRecord::Base
  extend EnumField::EnumeratedAttribute

  # in the database table there is a role_id integer column
  enumerated_attribute :role
end

Usage:

user.role = Role.manager
user.role_id == Role.manager.id  # will be true

Role.manager.name # :manager
user.role.name    # :manager

Role.names # [:admin, :manager, :employee]
Role.ids   # [1, 2, 3]

User.first.role.id == User.first.role_id  # will be true

Role[:manager]  == Role.manager # will be true
Role['manager'] == Role.manager # will be true

instance = Role[:employee]
instance.admin?    # false
instance.employee? # true

Your enum classes can have all the methods you need:

class PhoneType
  include EnumField::DefineEnum

  attr_reader :prefix

  def initialize(prefix)
    @prefix = prefix
  end

  define_enum do
    member :home,       object: new('045')
    member :commercial, object: new('044')
    member :mobile,     object: new('+380')
  end
end

user.phone_type.prefix # +380
user.phone_type.name   # :mobile

You have some AR like methods in enum classes

PhoneType.all == [PhoneType.home, PhoneType.commercial, PhoneType.mobile]  # ordered all
PhoneType.first == PhoneType.home
PhoneType.last == PhoneType.mobile

PhoneType.find_by_id(PhoneType.home.id) == PhoneType.home
PhoneType.find_by_id(123456) == nil # will not raise if id does not exists
PhoneType.safe_find(123456) == nil # just alias for find_by_id

PhoneType.find(2) == PhoneType.commercial
PhoneType.find(123456)  # will raise

PhoneType.find([1, 2]) == [PhoneType.home, PhoneType.commercial]

Start id from specific number

class CommentType
  include EnumField::DefineEnum

  define_enum id_start_from: 100 do
    member :video
    member :audio
    member :text
  end
end

CommentType.video.id # 101
CommentType.audio.id # 102
CommentType.text.id  # 103

Check if id exists

CommentType.valid_id?(-1)    # false
CommentType.valid_id?(0)     # false
CommentType.valid_id?(nil)   # false
CommentType.valid_id?(1)     # false
CommentType.valid_id?('101') # false
CommentType.valid_id?(:text) # false

CommentType.valid_id?(101)   # true

Check if name exists

CommentType.valid_name?('video') # true
CommentType.valid_name?(:video)  # true

CommentType.valid_name?(nil)     # false
CommentType.valid_name?(1)       # false
CommentType.valid_name?('wrong') # false
CommentType.valid_name?(:wrong)  # false

Tests

bundle install
bundle exec rspec ./spec/

LICENSE

(The MIT License)