Deleting Objects with subclasses in Swift Realm - swift

Question

I have a really simple database in Swift Realm for a todo app:
Items and their parent Categories.
The user can delete both the Items and the Categories with a simple swipe action. The action works fine, there are no issues when deleting Items. If I delete a Category, that works too, but I can still see the Items in the Realm Browser, those remain in the database even though there are no parent anymore. Obviously the user can't see these, they are doing nothing but still, it would be better to get rid of these with the parent Category. Are there any simple ways to do this?
class Category: Object{
#objc dynamic var name: String = ""
#objc dynamic var color: String = ""
#objc dynamic var order = 0
let items = List<Item>()
override static func primaryKey() -> String? {
return "order"
}
static func incrementalIDCat() -> Int {
let realm = try! Realm()
return (realm.objects(Category.self).max(ofProperty: "order") as Int? ?? 0) + 1
}
}
class Item: Object {
#objc dynamic var title: String = ""
#objc dynamic var done: Bool = false
#objc dynamic var dateCreated: Date?
#objc dynamic var order = 0
var parentCategory = LinkingObjects(fromType: Category.self, property: "items")
override static func primaryKey() -> String? {
return "order"
}
static func incrementalIDItem() -> Int {
let realm = try! Realm()
return (realm.objects(Item.self).max(ofProperty: "order") as Int? ?? 0) + 1
}
}
override func updateModel(at indexPath: IndexPath) {
if let categoryForDeletion = self.categories?[indexPath.row] {
do {
try self.realm.write {
self.realm.delete(categoryForDeletion)
}
} catch {
print("Error deleting category, \(error)")
}
}
tableView.reloadData()
}

Answer 1

You just delete items first.
self.realm.delete(categoryForDeletion.items)
self.realm.delete(categoryForDeletion)
Or, with this extension, you can do this.
self.realm.delete(categoryForDeletion, cascading: true)