Module | Sequel::Plugins::Serialization
In: | lib/sequel/plugins/serialization.rb

Sequel‘s built in Serialization plugin allows you to keep serialized ruby objects in the database, while giving you deserialized objects when you call an accessor.

This plugin works by keeping the serialized value in the values, and adding a @deserialized_values hash. The reader method for serialized columns will check the @deserialized_values for the value, return it if present, or deserialized the entry in @values and return it. The writer method will set the @deserialized_values entry. This plugin adds a before_save hook that serializes all @deserialized_values to @values.

You can specify the serialization format as a pair of serializer/deserializer callable objects. You can also specify the serialization format as a single symbol, if such a symbol has a registered serializer/deserializer pair in the plugin. By default, the plugin registers the :marshal, :yaml, and :json serialization formats. To register your own serialization formats, use Sequel::Plugins::Serialization.register_format. If you use yaml or json format, you need to require the libraries, Sequel does not do the requiring for you.

You can specify the columns to serialize when loading the plugin, or later using the serialize_attributes class method.

Because of how this plugin works, it must be used inside each model class that needs serialization, after any set_dataset method calls in that class. Otherwise, it is possible that the default column accessors will take precedence.

## Example

      require 'sequel'
      # Require json, as the plugin doesn't require it for you.
      require 'json'

      # Register custom serializer/deserializer pair
      Sequel::Plugins::Serialization.register_format(:reverse,
        lambda{|v| v.reverse},
        lambda{|v| v.reverse})

      class User < Sequel::Model
        # Built-in format support when loading the plugin
        plugin :serialization, :json, :permissions

        # Built-in format support after loading the plugin using serialize_attributes
        plugin :serialization
        serialize_attributes :marshal, :permissions

        # Use custom registered serialization format just like built-in format
        serialize_attributes :reverse, :password

        # Use a custom serializer/deserializer pair without registering
        serialize_attributes [lambda{|v| v.reverse}, lambda{|v| v.reverse}], :password
      end
      user = User.create
      user.permissions = { :global => 'read-only' }
      user.save

### Methods

apply configure register_format

### Classes and Modules

Module Sequel::Plugins::Serialization::ClassMethods
Module Sequel::Plugins::Serialization::InstanceMethods

### Constants

REGISTERED_FORMATS | = | {} |  | The default serializers supported by the serialization module. Use register_format to add serializers to this hash.

### Public Class methods

apply(model, *args)

Set up the column readers to do deserialization and the column writers to save the value in deserialized_values.

[Source]

        # File lib/sequel/plugins/serialization.rb, line 66
    66:       def self.apply(model, *args)
    67:         model.instance_eval do
    68:           @deserialization_map = {}
    69:           @serialization_map = {}
    70:         end
    71:       end

configure(model, format=nil, *columns)

Automatically call serialize_attributes with the format and columns unless no columns were provided.

[Source]

        # File lib/sequel/plugins/serialization.rb, line 75
    75:       def self.configure(model, format=nil, *columns)
    76:         model.serialize_attributes(format, *columns) unless columns.empty?
    77:       end

register_format(format, serializer, deserializer)

Register a serializer/deserializer pair with a format symbol, to allow models to pick this format by name. Both serializer and deserializer should be callable objects.

[Source]

        # File lib/sequel/plugins/serialization.rb, line 82
    82:       def self.register_format(format, serializer, deserializer)
    83:         REGISTERED_FORMATS[format] = [serializer, deserializer]
    84:       end

[Validate]