My problem instance's properties failed to share among the actions.
e.g. In action 'collect', I created an "CD" instance with some
"Album"s as its properties
using one-many relationship provided by rails API.
Before saving to the db, I just pass the 'CD' instance to action
'show', using @instance_var.
But I can't get properties information using 'cd.albums', it alway
return an empty array.
The reason why the objects do not get persisted is that modification
of objects is necessary.
Why can't I navigate through the relation and How can I pass around
the instance without?