Module: EnumField::EnumeratedAttribute

Defined in:
lib/enum_field/enumerated_attribute.rb

Overview

Easies the inclusion of enumerations as ActiveRecord columns. If you have a User AR, with a role_id column, you could do: <tt> class User

enumerated_attribute :role

end </tt>

This assumes a Role class, and will define role and role= methods in User class. These added methods expect an object of class Role, and Role should provide a find class method. You could get this by using Enumerated mixin

Similar to has_many :through in AR, it creates reader and writter methods to get enumerated atributes going through an intermediate model. For instance: <tt> class User

extend EnumField::EnumeratedAttribute

enumerated_attribute :role

end

class UserRole < ActiveRecord::Base

extend EnumField::EnumeratedAttribute

belongs_to :user
enumerated_attribute :role

end </tt> This assumes a Role class, the UserRole AR class is there just to persist the one-to-many relationship. This will define roles, roles=, role_ids and role_ids= methods in User class

Instance Method Summary collapse

Instance Method Details

#enumerated_attribute(name_attribute, options = {}) ⇒ Object

Define an enumerated field of the AR class

  • name_attribute: the name of the field that will be added, for instance role

  • options: Valid options are:

    * +id_attribute+: the name of the AR column where the enumerated id will be save. Defaults to
  +name_attribute+ with an +_id+ suffix.
* +class+: the class that will be instantiated when +name_attribute+ method is called. Defaults to
  +name_attribute+ in camelcase form.



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# File 'lib/enum_field/enumerated_attribute.rb', line 47

def enumerated_attribute(name_attribute, options = {})
  id_attribute = (options[:id_attribute] || "#{name_attribute}_id").to_sym
  klass = options[:class] || (options[:class_name] || name_attribute).to_s.camelcase.constantize

  define_method(name_attribute) do
    raw = send(id_attribute)
    klass.find_by_id(raw)
  end

  define_method("#{name_attribute}=") do |value|
    raw = EnumField::AttributeValueResolver.new(value, klass).resolve
    send("#{id_attribute}=", raw)
  end
end