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 use either marshal or yaml as the serialization format. If you use yaml, you should require yaml yourself.

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.

Methods

apply  

Classes and Modules

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

Public Class methods

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 24
24:       def self.apply(model, format, *columns)
25:         raise(Error, "Unsupported serialization format (#{format}), should be :marshal or :yaml") unless [:marshal, :yaml].include?(format)
26:         raise(Error, "No columns given.  The serialization plugin requires you specify which columns to serialize") if columns.empty?
27:         model.instance_eval do
28:           @serialization_format = format
29:           @serialized_columns = columns
30:           InstanceMethods.module_eval do
31:             columns.each do |column|
32:               define_method(column) do 
33:                 if deserialized_values.has_key?(column)
34:                   deserialized_values[column]
35:                 else
36:                   deserialized_values[column] = deserialize_value(@values[column])
37:                 end
38:               end
39:               define_method("#{column}=") do |v| 
40:                 changed_columns << column unless changed_columns.include?(column)
41:                 deserialized_values[column] = v
42:               end
43:             end
44:           end
45:         end
46:       end

[Validate]