Rails - Dec 2005 - Storing an object in the db

I''ve asked this before, but never got a working response.  I''d
like to
store an object inside a binary field in my db.  So I''d have a class
like this

class MyAwesomeClass
  def do_something_awesome
       ...
  end
end

then

class MyRecord < ActiveRecord::Base
end

the table my_record would have a binary field, my_object, that would
store an object of MyAwesomeClass.  So I could do:
r = MyRecord.new
r.my_object = MyAwesomeClass.new
r.reload
r.my_object.do_something_awesome

I saw that there''s a serialize helper, where I''d put this in
my AR class:
class MyRecord < ActiveRecord::Base
  serialize :my_object
end

But that doesn''t seem to be working, it just says my_object is a
string, and none of the MyAwesomeClass methods are available to it. 
I''d really appreciate any help with this.

Pat

You could try using a text field instead and storing the object in YAML 
format.

To convert an object to YAML, do an_object.to_yaml.

To restore the object, do an_object = YAML::load(a_model.object)

Jen

-- 
Posted via http://www.ruby-forum.com/.

# serialized data is going to be stored here
class Serializedobj < ActiveRecord::Base
	# this table has just two fields: id, data (type TEXT)
end


# this class is going to be serialized
class C
	attr_accessor :a, :b
	def initialize( a, b )
		@a, @b = a, b
	end
	def to_str
		a.to_s + '' '' + b.to_s
	end
end


		obj= C.new(''hi'', ''there'')  # create
something to be serialized
		so = Serializedobj.new     # create a place to store objects
		so.data = Marshal.dump obj # serialize obj
		so.save                    # save serialized data in db
		id = so.id                 # save id so we can restore obj later
		so = nil
		obj= nil

		so = Serializedobj.find_by_id( id ) # try to find serialized obj
		unless so
			raise Exception, ''serialization failed''
		end

		obj = Marshal.load so.data # reconstitute obj
		puts obj.to_str            # i''m alive!



Pat Maddox wrote:
> I''ve asked this before, but never got a working response. 
I''d like to
> store an object inside a binary field in my db.  So I''d have a
class
> like this
> 
> class MyAwesomeClass
>   def do_something_awesome
>        ...
>   end
> end
> 
> then
> 
> class MyRecord < ActiveRecord::Base
> end
> 
> the table my_record would have a binary field, my_object, that would
> store an object of MyAwesomeClass.  So I could do:
> r = MyRecord.new
> r.my_object = MyAwesomeClass.new
> r.reload
> r.my_object.do_something_awesome
> 
> I saw that there''s a serialize helper, where I''d put this
in my AR class:
> class MyRecord < ActiveRecord::Base
>   serialize :my_object
> end
> 
> But that doesn''t seem to be working, it just says my_object is a
> string, and none of the MyAwesomeClass methods are available to it. 
> I''d really appreciate any help with this.
> 
> Pat