symbol_mapper.rb

# Facilitate manipulating symbols as AR attribute values while storing them as other values in the DB
#
# Examples
#
#   class Example < ActiveRecord::Base
#     serialize :type, SymbolMapper.for(foo: 1, bar: 2, baz: 3)
#   end
#
#   example.type = :foo
#   # => :foo
#   example.read_attribute_before_type_cast(:type)
#   # => 3
#   example.reload.type
#   # => :foo
class SymbolMapper
  def self.for(mapping)
    new(mapping)
  end

  def initialize(mapping)
    @mapping = mapping
  end

  def load(val)
    @mapping.key(val)
  end

  def dump(sym)
    @mapping[sym]
  end
end