A Note on ActiveRecord Serialization and Objects

Let’s say you’re serializing a ruby object for later use in a field of another model.

class Foo < ActiveRecord::Base
  serialize :bar
end

In this instance, assume an object of type “Bar” is what’s being serialized. After save, the data appears fine, but when you retrieve the data, instead of your Object you end up with yaml that looks like this:

[#<YAML::Object:0x3fcade8 @ivars={"attributes_cache"=>{}, "attributes"=>{"updated_at"=>"2008-11-04 19:33:05", "id"=>"1", "message"=>"Hello World!", "created_at"=>"2008-11-04 19:33:05"}}, @class="Bar">

This most likely means that the model of the object being serialized is not loaded yet. This can be resolved by simply doing:

class Foo < ActiveRecord::Base
  Bar

  serialize :bar
end

This will load the model before serialization occurs and you’ll be all set.

This entry was posted on Sunday, April 19th, 2009 at 6:56 am and is filed under Rails, Ruby, Web Development. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.