Module: EnumType

Defined in:
lib/enum_type.rb

Overview

Adds the ‘enum_type` method to a model.

Examples:

Basic usage

class MyModel < ActiveRecord::Base
  extend EnumType
  enum_type :status, values: %w( open closed flagged deleted )
end

Instance Method Summary collapse

Instance Method Details

#enum_type(field, ..., options = {}) ⇒ Object

Defines a field whose type is an enumeration. Values are stored as strings in the backend (or your database’s enumerated type), however in the Rails level they are represented as symbols.

Examples:

Enumerated field with restricted types

enum_type :color, values: %w( red orange yellow green blue purple )

Parameters:

  • field (Symbol) —

    An enumerated field.

  • options (Hash) (defaults to: {}) —

    A hash of options.

Options Hash (options):

  • :allow_nil (true, false) — default: false —

    If ‘true`, a `nil` value is allowed.

  • :values (Array<String>) —

    If given, restricts valid values to those in the given array.

  • :register_type (String) —

    If ‘true`, registers the column’s type with the PostgreSQL adapter, to suppress “unknown OID” warnings.



30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
 
# File 'lib/enum_type.rb', line 30

def enum_type(*fields)
  options = fields.extract_options!

  fields.each do |field|
    define_method field do
      value = read_attribute(field)
      value ? value.to_sym : value
    end

    define_method :"#{field}=" do |value|
      write_attribute field, value.try(:to_s)
    end

    validates_presence_of(field) unless options[:allow_nil]
    validates_inclusion_of(field, in: options[:values].map(&:to_sym), allow_nil: options[:allow_nil]) if options[:values]

    if options[:register_type]
      #ActiveRecord::ConnectionAdapters::PostgreSQLAdapter::OID.register_type field.to_s,
      #                                                                       ActiveRecord::ConnectionAdapters::PostgreSQLAdapter::OID::Identity.new
      begin
        result   = connection.select_one("SELECT atttypid FROM pg_catalog.pg_attribute WHERE attrelid = #{connection.quote table_name}::regclass AND attname = #{connection.quote field.to_s}")
        type_oid = Integer(result['atttypid'])
        ActiveRecord::ConnectionAdapters::PostgreSQLAdapter::OID::TYPE_MAP[type_oid] =
          ActiveRecord::ConnectionAdapters::PostgreSQLAdapter::OID::Identity.new
      rescue => err
        Rails.logger.warn "Couldn't register type #{field}: #{err}"
      end
    end
  end
end