Diffable datasource in check history list

AutoCat/AppDelegate.swift

@@ -25,7 +25,7 @@ class AppDelegate: UIResponder, UIApplicationDelegate {
     func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
 		
         let config = Realm.Configuration(
-            schemaVersion: 27,
+            schemaVersion: 28,
             migrationBlock: { migration, oldSchemaVersion in
                 if oldSchemaVersion <= 3 {
                     var numbers: [String] = []

AutoCat/Extensions/Dated.swift

@@ -18,7 +18,7 @@ extension AudioRecord: Dated {
     }
 }
 
-extension RandomAccessCollection where Element: Dated & Equatable & Differentiable {
+extension RandomAccessCollection where Element: Dated & Hashable & Differentiable {
     func groupedByDate() -> [DateSection<Element>] {
         let now = Date()
         let monthStart = now.dateAtStartOf(.month)

AutoCat/Models/DateSection.swift

@@ -2,7 +2,7 @@ import Foundation
 import SwiftDate
 import DifferenceKit
 
-struct DateSection<T>: Differentiable, DifferentiableSection where T: Differentiable {
+struct DateSection<T>: Differentiable, DifferentiableSection, Hashable where T: Differentiable & Hashable {
     
 	var timestamp: Double = 0
     var header: String
@@ -59,4 +59,15 @@ struct DateSection<T>: Differentiable, DifferentiableSection where T: Differenti
     func isContentEqual(to source: DateSection<T>) -> Bool {
         return self.differenceIdentifier == source.differenceIdentifier
     }
+    
+    // MARK: - Hasable
+    
+    static func == (lhs: DateSection<T>, rhs: DateSection<T>) -> Bool {
+        return lhs.timestamp == rhs.timestamp && lhs.elements == rhs.elements
+    }
+    
+    func hash(into hasher: inout Hasher) {
+        hasher.combine(self.timestamp)
+        hasher.combine(self.elements)
+    }
 }

AutoCat/Models/VehicleAd.swift

@@ -3,7 +3,7 @@ import RealmSwift
 
 class VehicleAd: Object, Decodable {
     @objc dynamic var id: Int = 0
-    @objc dynamic var url: String = ""
+    @objc dynamic var url: String?
     @objc dynamic var price: String?
     @objc dynamic var date: TimeInterval = Date().timeIntervalSince1970
     @objc dynamic var mileage: String?

AutoCat/Utils/RxRealmDataSource.swift

@@ -3,7 +3,13 @@ import RealmSwift
 import DifferenceKit
 import ExceptionCatcher
 
-class RealmSectionedDataSource<Item,Cell>: NSObject, UITableViewDataSource where Item: Object & Identifiable & Dated & Differentiable, Cell: UITableViewCell & ConfigurableCell, Cell.Item == Item {
+class RealmDiffableDataSourse<Item>: UITableViewDiffableDataSource<DateSection<Item>, Item> where Item: Hashable & ContentEquatable & ContentIdentifiable {
+    override func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
+        return snapshot().sectionIdentifiers[section].header
+    }
+}
+
+class RealmSectionedDataSource<Item,Cell> where Item: Object & Identifiable & Dated & Differentiable, Cell: UITableViewCell & ConfigurableCell, Cell.Item == Item {
     
     private var tv: UITableView
     private var data: Results<Item>
@@ -11,97 +17,31 @@ class RealmSectionedDataSource<Item,Cell>: NSObject, UITableViewDataSource where
     private var sections: [DateSection<Item>] = []
     private var cellIdentifier: String
     private var lastUpdateTime = Date()
+    private var dataSource: RealmDiffableDataSourse<Item>!
     
     init(table: UITableView, data: Results<Item>, cellIdentifier: String = String(describing: Cell.self)) {
         self.tv = table
         self.data = data
         self.cellIdentifier = cellIdentifier
-        super.init()
+        
-        self.tv.dataSource = self
+        self.dataSource = RealmDiffableDataSourse<Item>(tableView: table) { tv, ip, model -> UITableViewCell? in
+            let cell = tv.dequeueReusableCell(withIdentifier: self.cellIdentifier, for: ip) as? Cell
+            cell?.configure(with: model)
+            return cell
+        }
+        self.tv.dataSource = self.dataSource
         
         self.notificationToken = self.data.observe { changes in
             switch changes {
             case .initial:
-                self.sections = self.data.groupedByDate()
+                self.reload(animated: false)
-                self.tv.reloadData()
+            case .update(_, _, _, _):
-            case .update(_, let deletions, let insertions, let modifications):
+                self.reload(animated: true)
-                if !Calendar.current.isDateInToday(self.lastUpdateTime) {
-                    self.sections = self.data.groupedByDate()
-                    self.tv.reloadData()
-                    return
-                }
-                
-                var actions = "Deletions: \(deletions), Insertions: \(insertions), Modifications: \(modifications)"
-                let newSections = self.data.groupedByDate()
-                let changeset = StagedChangeset(source: self.sections, target: newSections, section: 0)
-                
-                do {
-                    try ExceptionCatcher.catch {
-                        self.tv.beginUpdates()
-                        self.tv.deleteRows(at: deletions.map(self.indexPath), with: .automatic)
-                        self.sections = self.data.groupedByDate()
-                        self.tv.insertRows(at: insertions.map(self.indexPath), with: .automatic)
-                        self.tv.reloadRows(at: modifications.map(self.indexPath), with: .automatic)
-                        
-                        actions += "\n" + "Changesets count: \(changeset.count)"
-                        if let firstChangeset = changeset.first {
-                            actions += "\n" + "Deletions: \(firstChangeset.elementDeleted.map { $0.element })"
-                            actions += "\n" + "Insertions: \(firstChangeset.elementInserted.map { $0.element })"
-                            self.tv.deleteSections(IndexSet(firstChangeset.elementDeleted.map { $0.element }), with: .automatic)
-                            self.tv.insertSections(IndexSet(firstChangeset.elementInserted.map { $0.element }), with: .automatic)
-                        }
-                        self.tv.endUpdates()
-                    }
-                } catch {
-                    let msg = error.localizedDescription + "\n\n" + actions
-                    let alert = UIAlertController(title: "Error", message: msg, preferredStyle: .alert)
-                    alert.addAction(UIAlertAction(title: "OK", style: .default, handler: nil))
-                    self.tv.window?.rootViewController?.present(alert, animated: true)
-                }
             case .error(let err):
                 print("Realm observer error: \(err)")
             }
         }
     }
-
-    // Here I assume that sections keep order of elements the same as in initial flat collection
-    // Otherwise it will not work properly
-    func indexPath(by index: Int) -> IndexPath {
-        var sectionStartIndex = 0
-        for (i, section) in self.sections.enumerated() {
-            if index < sectionStartIndex + section.elements.count {
-                return IndexPath(row: index - sectionStartIndex, section: i)
-            }
-            
-            sectionStartIndex += section.elements.count
-        }
-        
-        return IndexPath(row: 0, section: 0)
-    }
-    
-    // MARK: - UITableViewDataSource
-    
-    func numberOfSections(in tableView: UITableView) -> Int {
-        return self.sections.count
-    }
-    
-    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
-        return self.sections[section].elements.count
-    }
-    
-    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
-        guard let cell = tableView.dequeueReusableCell(withIdentifier: self.cellIdentifier, for: indexPath) as? Cell else {
-            return UITableViewCell()
-        }
-        
-        let item = self.sections[indexPath.section].elements[indexPath.row]
-        cell.configure(with: item)
-        return cell
-    }
-    
-    func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
-        return self.sections[section].header
-    }
     
     // MARK: - Public
     
@@ -109,8 +49,13 @@ class RealmSectionedDataSource<Item,Cell>: NSObject, UITableViewDataSource where
         return self.sections[indexPath.section].elements[indexPath.row]
     }
     
-    func reload() {
+    func reload(animated: Bool = true) {
         self.sections = self.data.groupedByDate()
-        self.tv.reloadData()
+        var snapshot = NSDiffableDataSourceSnapshot<DateSection<Item>, Item>()
+        snapshot.appendSections(self.sections)
+        for section in self.sections {
+            snapshot.appendItems(section.elements, toSection: section)
+        }
+        self.dataSource.apply(snapshot, animatingDifferences: animated, completion: nil)
     }
 }

AutoCat/Utils/RxSectionedDataSource.swift

@@ -3,7 +3,7 @@ import DifferenceKit
 import RxSwift
 import RxCocoa
 
-class  RxSectionedDataSource<Item,Cell>: NSObject, UITableViewDataSource where Item: Dated & Equatable & Differentiable, Cell: UITableViewCell & ConfigurableCell, Cell.Item == Item {
+class  RxSectionedDataSource<Item,Cell>: NSObject, UITableViewDataSource where Item: Dated & Hashable & Differentiable, Cell: UITableViewCell & ConfigurableCell, Cell.Item == Item {
     private var tv: UITableView
     private var cellIdentifier: String
     private var sections: [DateSection<Item>] = []