How to associate descendant models to a parent

I have the following models:

Account
  has_many :libraries

Library
  has_many :topics
  belongs_to :account

Topic
  has_many :functions
  belongs_to :library

Function
  has_one :example
  belongs_to :topic

Example
  belongs_to :function

I would like to be able to able to do things such as:

some_account.libraries
some_account.topics
some_account.functions
some_account.examples

In addition, I would like to be able to assign an account to a descendant, i.e

some_example.account = some_account
some_function.account = some_account
some_topic.account = some_account
some_library开发者_Python百科.account = some_account

To give some context: I am letting a user (Account) create each Library, Topic, Function, Example. record separately. Then a user is free to change how the records are associated: Change the topic of a Function, move a Topic to a different Library, add an example to a function, and so on.

To my understanding no matter what record is created, I would need to assign it to a user (account) so that I can have a list of each Model records that a user has created, as well as prevent other users from seeing stuff that doesn't belong to them

Although I might be overcomplicating, I really don't know :(

Thanks in advance.

Just put

belongs_to :account

on each entity a user can make... and add a foreign key, and

Account
  has_many :libraries
  has_many :topics
  has_many :functions
  has_many :examples

(Note: I use the hobo_fields gem to make migrations easier)

That way.. if they change which functions are in which topics etc.. you can't loose who created it.

If you want to make sure users cannot add their topics to someone else's library just put validation on the record to prevent it.