Most efficient way to save object references in iOS?

Question

In the application I am working on, I have a note object. This note object can have one super note and many sub-notes; essentially, I am creating a note hierarchy. The way in which it functions is actually very similar to UIView.

Anyhow, I need to be able to save this data. I've worked with Core Data and understand that you can create relationships between particular objects and each of these managed objects can have primitive properties (excepting transformable types). However, I am unsure whether creating a relationship between a note, its superview, and its subviews is the most practical-or even possible- way to do this.

That being said, I wanted to get some perspective. If I have to save an array of notes, and many of these notes have references to each other (in the same way that views do), what is the best way to do this?

Answer 1

Here's how I would do it:

1) Use Core Data and (optionally) Mogenerator. Especially as your app's functionality continues to grow, you'll be glad you did.

2) Create a Note entity in the data model.

3) On the Note entity, create a to-many relationship, called notes, that points to Note (to itself) with an inverse to-one relationship, called parentNote. So, you would have a two way relationship like this:

parentNote <<---> notes (meaning: one parentNote and one or more notes)

Point of interest

As you mentioned, UIView does something quite similar to this. Basically, each UIView has an array of subviews and each subview references its parent view, superview. So you have this two-way relationship on each UIView:

superview <<---> subviews

Screenshots per request:

Note entity showing the relationships only:

The notes relationship:

The parentNote relationship:

Also of interest are the delete rules - I'd recommend you set cascade on notes and nullify on parentNote relationship (this would imply that a parentNote owns its children notes, so when it is deleted, they are too). However, make sure this is the behavior you want.