enum_field¶ ↑
Description:¶ ↑
Enables Active Record attributes to point to enum like objects, by saving in your database only an integer ID.
Features:¶ ↑
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Allows creation of Classes with enum like behaviour.
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Allows any number of members and methods in the enum classes.
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Allows an integer id to be used in your database columns to link to the enum members (user.role_id)
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Enables higher abstraction interaction with
AR
attributes:-
user.role = Role.admin
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if user.role.can_edit?
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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.
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You can create a roles, states or countries table, and dump there all possible values.
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You can use a string to identify, for instance, the role.
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You can use an id to identify the role.
If you are not confortable with any of this options, maybe enum_field
is an answer for you.
Basic usage:¶ ↑
class Role define_enum do |builder| builder.member :admin builder.member :manager builder.member :employee end end class User < ActiveRecord::Base # in the database table there is a role_id integer column enumerated_attribute :role end link_to_if(current_user.role == Role.admin, edit_foo_path(@foo)) user.role = Role.manager user.role_id == Role.manager.id #will be true User.first.role.id == User.first.role_id #will be true
Your enum classes can have all the methods you need:
class PhoneType def initialize(name) @name = name end attr_reader :name define_enum do |b| b.member :home, :object => PhoneType.new('home') b.member :commercial, :object => PhoneType.new('commercial') b.member :mobile, :object => PhoneType.new('mobile') end end user.phone.type.name
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 PhoneType.find(2) == PhoneType.commercial PhoneType.find(123456) # will raise
The library also mimics has_many :through behavior, for cases such as:
class Role define_enum do |builder| builder.member :admin builder.member :manager builder.member :employee end end class User has_many_enumerated_attributes :roles, :through => UserRole end class UserRole < ActiveRecord::Base belongs_to :user enumerated_attribute :role end user = User.create user.role = [Role.manager, Role.admin] user.roles.include?(Role.admin) #will be true user.roles.include?(Role.manager) #will be true user.roles.include?(Role.employee) #will be false user.role_ids.include?(Role.manager.id) #will be true user.role_ids = [Role.employee.id] user.roles.include?(Role.employee) #will be true user.roles.include?(Role.admin) #will be false
Requirements:¶ ↑
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activerecord
Install:¶ ↑
sudo gem install enum_field
License:¶ ↑
(The MIT License)
Copyright © 2009 Sebastián Bernardo Galkin
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.