How to store system-created to-do list items? - oop

Question

In a to-do list where users have both system-created items and their own items, how would you store the items?
A to-do list can have a mix of items. The system-created items can be modified and deleted just like user-created items. There difference is the titles and description text for the system-created items are initially pulled from a configuration. Many users can have the same system-created items. E.g. if two users want to paint rooms in their houses, they'd both get "buy paint" items.
Option 1
Save the full system-created items (including the title & text) with the user-created items.
Pros: Flexibility for user modifications since the items belong to the user and are not dependent on a central item configuration.
Cons: Lots of redundancy because there will be many users all with the same items.
Option 2
Save references to a configuration for system-created items with the user-created items.
Pros: Flexibility for system modifications since if we want to say "buy X-brand paint" instead of "buy paint", the change is easily reflected for all users with this item.
Cons: System-created items have to persist forever in the configuration even if the item is no longer relevant for new to-do lists because otherwise the user's reference will be broken.
Other options?
Thank you!

Answer 1

My initial thought is - what is your requirement? Your user-flows and project road-map might contain information to inform your design.
From your question "system-created items can be modified and deleted just like user-created items":
This indicates that you are going to have to have a way to track modifications to your 'system-created' templates per user or convert them to 'user-created' messages when they are edited.
This is more complexity than you seem to need
It seems much simpler to create messages from system templates, then have them be regular messages.
A bit of extra storage is not going to break the bank
You have not mentioned any case where you would need to operate over only system-created to-do's. But in this case, you could include created-by metadata.

Answer 2

I think the key here is whether you need to be able to modify a "system todo", and that change to be reflected in all the "user todos"...
If that's a requirement (it sounds sensible to me), your only option is Option 2 - the real con of Option 1 is once you copied the "system todo" as a "user todo", you cannot tell anymore whether they're related...
I'd go for a model similar to this, with 2 entities/tables:
ToDoTemplate
Integer id
String name
String description
ToDoItem
Integer id
ToDoTemplate template
Boolean completed = false
?String name = null
?String description = null
When you create a ToDoItem, you create it based on a ToDoTemplate (it may be a blank template), and you set the name and description as null, reusing the template name/description... Only if the user modifies their own ToDoItem is when you store that value... i.e.
String getName() {
return this.name != null ? this.name : this.template.name;
}
This is the most flexible of the approaches, and the only valid in many situations... Note the con you mention:
Cons: System-created items have to persist forever in the configuration even if the item is no longer relevant for new to-do lists because otherwise the user's reference will be broken.
This is not a con really - as long as there's one ToDoItem that uses a given ToDoTemplate, the template is still relevant, and of course there's no reason to remove it...