ActiveRecord in Rails 2.1.0 misbehaving for Aggregate Attr.

I am not sure if this is a bug in ActiveRecord or is this the intended behavior. If it is then it does not make sense to me.

In a nutshell: If you change an aggregate object attribute created via composed_of method (see Agile Web Development - Second Edition Chapter 17 page 313 onwards) and then save the model, the change to the model (composite attribute specifically) will not be saved UNLESS you explicitly set the partial_updates attribute for that model to false. N Specific use-case:

I have an Account model that shadows the accounts table in database. This account object contains a composite object (amongst others) called BillingAddress defined within the Account model class as follows:

  composed_of :billing_address,     :mapping => [%w(address_1 address_1), %w(address_2 address_2), %w(address_3 address_3),                  %w(city city), %w(state state), %w(zip zip), %w(card_country country)] do |params|           params                  end

To test this theory, in the Rails Console, I "found" and existing Account object in the database using

acct = Account.find(id) -- where id is a specific account id

Now I create a billing address object:

ba ="123 Lane", nil, nil, "City", "State", "12345", "USA")

Next, I assigned the newly created billing object to the account object's billing_address composite attribute as follows:

acct.billing_address = ba

Now if I save this as:

Then no update statement is triggered as it does in Rails 2.0.2.

If however, I set the partial_updates for the Account class to false BEFORE assigning the ba value to acct.billing_address then the update statement is triggered. That is:

Account.partial_updates = false acct.billing_address = ba

This will trigger the update which is what I want.

Note that partial_updates works as stated for simple attribute updates. That is:

Account.partial_updates = true acct.address_1 = 'xyz street'

correctly triggers the partial update where only the address_1 attribute is updated in the database.

Has anyone else experienced a similar problem with composite attributes?