Fix id of Items, saving

CHDataManagement/Model/Content.swift

@@ -2,7 +2,7 @@ import Foundation
 import SwiftUI
 import Combine
 
-final class Content: ObservableObject {
+final class Content: ChangeObservableItem {
 
     @ObservedObject
     var storage: Storage
@@ -47,6 +47,8 @@ final class Content: ObservableObject {
 
     var errorCallback: ((StorageError) -> Void)?
 
+    var cancellables: Set<AnyCancellable> = []
+
     /// A cache of file sizes
     private var fileSizes: [String: Int] = [:]
 
@@ -200,9 +202,9 @@ final class Content: ObservableObject {
             for file in self.files {
                 guard file.type.isVideo else { continue }
                 guard !file.isExternallyStored else { continue }
-                guard !storage.hasVideoThumbnail(for: file.id) else { continue }
-                if await imageGenerator.createVideoThumbnail(for: file.id) {
-                    print("Generated thumbnail for \(file.id)")
+                guard !storage.hasVideoThumbnail(for: file.identifier) else { continue }
+                if await imageGenerator.createVideoThumbnail(for: file.identifier) {
+                    print("Generated thumbnail for \(file.identifier)")
                     file.didChange()
                 }
             }
@@ -229,6 +231,10 @@ final class Content: ObservableObject {
         self.lastSave = .now
     }
 
+    func needsSaving() {
+        needsSave()
+    }
+
     // MARK: File sizes
 
     func size(of file: String) -> Int? {