Methods
Instance Public methods
serialize(attr_name, class_name_or_coder = Object)
Link
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 assignment and
retrieval. Otherwise SerializationTypeMismatch
will be raised.
Parameters
-
attr_name
- The field name that should be serialized. -
class_name_or_coder
- Optional, a coder object, which responds to `.load` / `.dump` or a class name that the object type should be equal to.
Example
# Serialize a preferences attribute.
class User < ActiveRecord::Base
serialize :preferences
end
# Serialize preferences using JSON as coder.
class User < ActiveRecord::Base
serialize :preferences, JSON
end
# Serialize preferences as Hash using YAML coder.
class User < ActiveRecord::Base
serialize :preferences, Hash
end
# File activerecord/lib/active_record/attribute_methods/serialization.rb, line 38 def serialize(attr_name, class_name_or_coder = Object) # When ::JSON is used, force it to go through the Active Support JSON encoder # to ensure special objects (e.g. Active Record models) are dumped correctly # using the #as_json hook. coder = if class_name_or_coder == ::JSON Coders::JSON elsif [:load, :dump].all? { |x| class_name_or_coder.respond_to?(x) } class_name_or_coder else Coders::YAMLColumn.new(class_name_or_coder) end decorate_attribute_type(attr_name, :serialize) do |type| Type::Serialized.new(type, coder) end end
serialized_attributes()
Link
# File activerecord/lib/active_record/attribute_methods/serialization.rb, line 55 def serialized_attributes ActiveSupport::Deprecation.warn(" `serialized_attributes` is deprecated without replacement, and will be removed in Rails 5.0. ".squish) @serialized_attributes ||= Hash[ columns.select { |t| t.cast_type.is_a?(Type::Serialized) }.map { |c| [c.name, c.cast_type.coder] } ] end