Module: ActiveRecord::AttributeMethods::Serialization::ClassMethods

Defined in:
lib/serialize-rails/serialization.rb

Instance Method Summary collapse

Instance Method Details

#serialize(attr_name, *args) ⇒ Object

If you have an attribute that needs to be saved to the database as an object, and retrieved as the same object, then specify the name of that attribute using this method and it will be handled automatically. The serialization is done through YAML. If class_name is specified, the serialized object must be of that class on retrieval or SerializationTypeMismatch will be raised.

Parameters

  • attr_name - The field name that should be serialized.

  • class_name - Optional, class name that the object type should be equal to.

Example

# Serialize a preferences attribute.
class User < ActiveRecord::Base
  serialize :preferences
end



28
29
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
60
61
62
63
64
65
66
67
 
# File 'lib/serialize-rails/serialization.rb', line 28

def serialize(attr_name, *args)
  include Behavior if defined? Behavior # Rails 4

  options = args.shift
  if options.is_a? Hash
    class_name = Object
  else
    class_name = options || Object
    options = args.shift || Hash.new
  end

  default_options = {
    :format => :yaml,
    :gzip => false
  }
  options = default_options.merge(options)

  coder = if [:load, :dump].all? { |x| class_name.respond_to?(x) }
            class_name
          else
            upcase_formats = [:json, :xml, :yaml]
            coder_class = if upcase_formats.include?(options[:format])
              options[:format].to_s.upcase
            else
              options[:format].to_s.camelize
            end
            coder_class = begin
              "ActiveRecord::Coders::#{coder_class}Column".constantize
            rescue
              Coders::YAMLColumn
            end
            coder_class.new(class_name)
          end

  coder = Coders::GzipColumn.new(coder) if options[:gzip]

  # merge new serialized attribute and create new hash to ensure that each class in inheritance hierarchy
  # has its own hash of own serialized attributes
  self.serialized_attributes = serialized_attributes.merge(attr_name.to_s => coder)
end