ManagedEnum

A ruby gem for adding managed enumerated fields functionality to ActiveRecord models. This code is published under the MIT-LICENSE.

Installation

This gem was developed and tested for rails 3.2.17 on ruby 1.9.3.

gem install managed_enum

Usage

The main method is has_managed_enum. This method takes a symbol (attribute name) as the first argument, and either an array or a hash for the second argument. If you are intending to save the enumerated field as string, send an array of possible key values. If you are intending to save the enumerated field as integer, send a hash containing keys as names (to be used in your code) and values (to be saved in database for faster searching and indexing).

class Person < ActiveRecord::Base
  attr_accessible :age_phase, :name, :status
  
  has_managed_enum :age_phase, {baby: 10, child: 20, young: 30, man: 40, old: 50}
  has_managed_enum :status, %w(employed self_employed entrepreneur unemployed)
end

Now you are free to use a bunch of useful class and instance methods.

# CLASS METHODS
Person.age_phase_possible_keyvalues
# => {baby: 10, child: 20, young: 30, man: 40, old: 50}

Person.status_possible_keyvalues
# => ["employed", "self_employed", "entrepreneur", "unemployed"]

Person.BABY
# => 10

Person.CHILD
# => 20

Person.EMPLOYED
# => "employed"

Person.SELF_EMPLOYED
# => "self_employed"

Person.age_phase_baby.all
# => Person Load (0.2ms)  SELECT "people".* FROM "people" WHERE "people"."age_phase" = 10

Person.status_employed.all
# => Person Load (0.2ms)  SELECT "people".* FROM "people" WHERE "people"."status" = "employed"
 
# INSTANCE METHODS
person = Person.new

person.baby?
# => returns false
person.make_baby
# => 10
person.baby?
# => returns true
person.age_phase
# => returns 10
person.age_phase_as_string
# => returns "baby"

person.employed?
# => returns false
person.make_employed
# => "employed"
person.employed?
# => returns true
person.status
# => returns "employed"
person.status_as_string
# => returns "employed"

Contribution

Feel free to contribute for upward compatibility, better coding style or adding functionality.