HistoryView: Adds ability to delete history items

App/Backend/History/BrowserHistory.swift

@@ -7,9 +7,58 @@
 
 import Foundation
 import CoreData
+import Combine
 
 class BrowserHistory
 {
+    class ViewModel: NSObject, ObservableObject, NSFetchedResultsControllerDelegate {
+        @Published var searchQuery: String = ""
+        @Published private(set) var historyItems: [HistoryItem] = []
+        
+        fileprivate let historyController: BrowserHistory
+        fileprivate var searchQueryObserver: AnyCancellable? = nil
+        fileprivate var fetchedResultsController: NSFetchedResultsController<HistoryItemEntity> {
+            didSet { fetchedResultsController.delegate = self; performInitialFetch() }
+        }
+        
+        fileprivate init(fetchedResultsController: NSFetchedResultsController<HistoryItemEntity>, historyController: BrowserHistory) {
+            self.fetchedResultsController = fetchedResultsController
+            self.historyController = historyController
+            super.init()
+            
+            searchQueryObserver = $searchQuery.sink { [unowned self] newValue in
+                self.fetchedResultsController = historyController.fetchRequestController(forQuery: newValue)
+            }
+        }
+        
+        public func item(forIdentifier identifier: HistoryItem.ID) -> HistoryItem? {
+            if let object = fetchedResultsController.managedObjectContext.object(with: identifier) as? HistoryItemEntity {
+                return HistoryItem(entity: object)
+            }
+            
+            return nil
+        }
+        
+        public func deleteItems(_ items: Set<HistoryItem.ID>) {
+            items.forEach { identifier in
+                historyController.deleteItem(withIdentifier: identifier)
+            }
+        }
+        
+        func controllerDidChangeContent(_ controller: NSFetchedResultsController<NSFetchRequestResult>) {
+            if let objects = controller.fetchedObjects as? [HistoryItemEntity] {
+                self.historyItems = objects.map { HistoryItem(entity: $0) }
+            }
+        }
+        
+        fileprivate func performInitialFetch() {
+            try? fetchedResultsController.performFetch()
+            if let objects = fetchedResultsController.fetchedObjects {
+                self.historyItems = objects.map { HistoryItem(entity: $0) }
+            }
+        }
+    }
+    
     static public let shared = BrowserHistory()
     
     lazy fileprivate var persistentContainer: NSPersistentContainer = {
@@ -37,19 +86,30 @@ class BrowserHistory
         }
     }
     
-    public func allHistory(limit: Int? = nil) -> [HistoryItem] {
+    public func viewModel(forFilterString filterString: String? = nil, limit: Int? = nil) -> ViewModel {
-        let dataContext = persistentContainer.viewContext
+        let resultsController = fetchRequestController(forQuery: filterString, limit: limit)
-        
+        return ViewModel(fetchedResultsController: resultsController, historyController: self)
-        let fetchRequest: NSFetchRequest<HistoryItemEntity> = HistoryItemEntity.fetchRequest()
+    }
-        fetchRequest.sortDescriptors = [
+    
-            // Sort by date
+    public func historyItem(forIdentifier: HistoryItem.ID) -> HistoryItem? {
-            NSSortDescriptor(keyPath: \HistoryItemEntity.lastVisited, ascending: false)
+        if let entity = try? persistentContainer.viewContext.existingObject(with: forIdentifier) as? HistoryItemEntity {
-        ]
+            return HistoryItem(entity: entity)
-        
-        if let limit {
-            fetchRequest.fetchLimit = limit
         }
         
+        return nil
+    }
+    
+    public func deleteItem(withIdentifier identifier: HistoryItem.ID) {
+        let dataContext = persistentContainer.viewContext
+        if let object = try? dataContext.existingObject(with: identifier) {
+            dataContext.delete(object)
+            try? dataContext.save()
+        }
+    }
+    
+    public func allHistory(filteredBy filterString: String? = nil, limit: Int? = nil) -> [HistoryItem] {
+        let dataContext = persistentContainer.viewContext
+        let fetchRequest = fetchRequest(forStringContaining: filterString, limit: limit)
         let entities: [HistoryItemEntity] = (try? dataContext.fetch(fetchRequest)) ?? []
         
         return entities.map { (entity) -> HistoryItem in
@@ -98,6 +158,38 @@ class BrowserHistory
     }
 }
 
+extension BrowserHistory
+{
+    fileprivate func fetchRequestController(forQuery query: String? = nil, limit: Int? = nil) -> NSFetchedResultsController<HistoryItemEntity> {
+        let fetchRequest = fetchRequest(forStringContaining: query, limit: limit)
+        return NSFetchedResultsController(fetchRequest: fetchRequest,
+                                          managedObjectContext: persistentContainer.viewContext,
+                                          sectionNameKeyPath: nil, cacheName: nil)
+    }
+    
+    fileprivate func fetchRequest(forStringContaining filterString: String? = nil, limit: Int? = nil) -> NSFetchRequest<HistoryItemEntity> {
+        let fetchRequest: NSFetchRequest<HistoryItemEntity> = HistoryItemEntity.fetchRequest()
+        fetchRequest.sortDescriptors = [
+            // Sort by date
+            NSSortDescriptor(keyPath: \HistoryItemEntity.lastVisited, ascending: false)
+        ]
+        
+        if let limit {
+            fetchRequest.fetchLimit = limit
+        }
+        
+        if let filterString, filterString.count > 0 {
+            fetchRequest.predicate = NSPredicate(format: """
+                                                 host CONTAINS[cd] %@
+                                                 OR title CONTAINS[cd] %@
+                                                 OR url CONTAINS[cd] %@
+                                                 """, filterString, filterString, filterString)
+        }
+
+        return fetchRequest
+    }
+}
+
 extension URL
 {
     public func topLevelURL() -> URL {

App/Backend/History/HistoryItem.swift

@@ -12,13 +12,13 @@ struct HistoryItem: Hashable, Identifiable
     var url: URL
     var title: String
     var lastVisited: Date
-    var id: ObjectIdentifier
+    var id: NSManagedObjectID
     
     init(entity: HistoryItemEntity) {
         self.url = entity.url ?? URL(string: "about:blank")!
         self.lastVisited = entity.lastVisited ?? Date()
         self.title = entity.title ?? ""
-        self.id = entity.id
+        self.id = entity.objectID
     }
     
     // For testing/previews
@@ -26,6 +26,6 @@ struct HistoryItem: Hashable, Identifiable
         self.url = url
         self.title = title
         self.lastVisited = lastVisited
-        self.id = ObjectIdentifier(NSUUID())
+        self.id = NSManagedObjectID()
     }
 }

App/History UI/HistoryBrowserViewController.swift

@@ -11,7 +11,7 @@ import UIKit
 @MainActor
 class HistoryBrowserViewController: UIHostingController<HistoryView> {
     public init() {
-        super.init(rootView: HistoryView(historyItems: BrowserHistory.shared.allHistory(limit: 500)))
+        super.init(rootView: HistoryView(viewModel: BrowserHistory.shared.viewModel(limit: 500)))
     }
     
     required dynamic init?(coder aDecoder: NSCoder) {

App/History UI/HistoryView.swift

@@ -9,24 +9,19 @@ import SwiftUI
 import UniformTypeIdentifiers
 
 struct HistoryView: View {
-    var historyItems: [HistoryItem]
+    @StateObject public var viewModel: BrowserHistory.ViewModel
-    
-    private let dateFormatter: DateFormatter
     @State public var selectedItems = Set<HistoryItem.ID>()
-    @Environment(\.dismiss) private var dismissAction
     
-    init(historyItems: [HistoryItem]) {
+    private let dateFormatter = DateFormatter() .. {
-        self.historyItems = historyItems
+        $0.locale = Locale.current
-        
+        $0.dateStyle = .medium
-        let formatter = DateFormatter()
+        $0.timeStyle = .short
-        formatter.locale = Locale.current
-        formatter.dateStyle = .medium
-        formatter.timeStyle = .short
-        self.dateFormatter = formatter
     }
     
+    @Environment(\.dismiss) private var dismissAction
+    
     var body: some View {
-        Table(historyItems, selection: $selectedItems) {
+        Table(viewModel.historyItems, selection: $selectedItems) {
             TableColumn("Title", value: \.title)
             
             TableColumn("URL") { item in
@@ -38,34 +33,30 @@ struct HistoryView: View {
             }
         }
         .contextMenu(forSelectionType: HistoryItem.ID.self, menu: { items in
-            if let firstItem: HistoryItem.ID = items.first,
+            let historyItems = items.compactMap { viewModel.item(forIdentifier: $0) }
-               let historyItem = historyItems.first { $0.id == firstItem }
+            Button("Copy") {
-            {
+                UIPasteboard.general.setItems(historyItems.map { [
-                Button("Copy") {
+                    UTType.url.identifier           : $0.url,
-                    UIPasteboard.general.addItems([
+                    UTType.utf8PlainText.identifier : $0.url.absoluteString,
-                        [ UTType.url.identifier : historyItem.url ]
+                ] })
-                    ])
+            }
-                }
+            
-                
+            Button("Delete") {
-                // TODO: Delete?
+                viewModel.deleteItems(items)
             }
         }, primaryAction: { items in
-            if let firstItem: HistoryItem.ID = items.first,
+            items.compactMap({ viewModel.item(forIdentifier: $0) }).forEach { item in
-               let historyItem = historyItems.first(where: { $0.id == firstItem })
+                UIApplication.shared.open(item.url)
-            {
-                UIApplication.shared.open(historyItem.url)
                 dismissAction()
             }
         })
+        .searchable(text: $viewModel.searchQuery)
     }
 }
 
 struct HistoryViewPreviewProvider: PreviewProvider {
     static var previews: some View {
-        HistoryView(historyItems: [
+        HistoryView(viewModel: BrowserHistory.shared.viewModel())
-            HistoryItem(url: URL(string: "https://apple.com")!, title: "Apple", lastVisited: Date.now),
-            HistoryItem(url: URL(string: "https://google.com")!, title: "Google", lastVisited: Date.now)
-        ])
             .previewLayout(.fixed(width: 480.0, height: 800.0))
     }
 }

App/Utilities/UIView+Utils.swift

@@ -7,6 +7,15 @@
 
 import UIKit
 
+infix operator .. : AssignmentPrecedence
+
+@discardableResult @inline(__always) @inlinable
+public func .. <T: Any>(it: T, apply: (inout T) throws -> Void) rethrows -> T {
+    var it = it
+    try apply(&it)
+    return it
+}
+
 protocol Conf { }
 
 extension Conf {