20 minute interval, selfhosted servers, works, whoa

ntfy/App/AppDelegate.swift

@@ -6,7 +6,8 @@ import FirebaseCore
 import CoreData
 
 class AppDelegate: UIResponder, UIApplicationDelegate, ObservableObject {
-    let tag = "AppDelegate"
+    private let tag = "AppDelegate"
+    private let pollTimerTopic = "~poll" // See ntfy server if ever changed
     
     // Implements navigation from notifications, see https://stackoverflow.com/a/70731861/1440785
     @Published var selectedBaseUrl: String? = nil
@@ -30,9 +31,49 @@ class AppDelegate: UIResponder, UIApplicationDelegate, ObservableObject {
         // Set self as messaging delegate
         Messaging.messaging().delegate = self
         
+        // Register to timerkeeper topic
+        Messaging.messaging().subscribe(toTopic: pollTimerTopic)
+        
         return true
     }
     
+    /// Executed when a background notification arrives. This is used to trigger polling of local topics.
+    /// See https://developer.apple.com/documentation/usernotifications/setting_up_a_remote_notification_server/pushing_background_updates_to_your_app
+    func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable : Any], fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {
+        Log.d(tag, "Background notification received", userInfo)
+        
+        // Exit out early if this message is not expected
+        let topic = userInfo["topic"] as? String ?? ""
+        if topic != pollTimerTopic {
+            completionHandler(.noData)
+            return
+        }
+
+        // Poll and display new messages
+        let store = Store.shared
+        let center = UNUserNotificationCenter.current()
+        let subscriptionManager = SubscriptionManager(store: store)
+        
+        store.getSubscriptions()?.forEach { subscription in
+            subscriptionManager.poll(subscription) { messages in
+                messages.forEach { message in
+                    let content = UNMutableNotificationContent()
+                    content.title = message.title ?? ""
+                    content.body = message.message ?? ""
+                    content.sound = .default
+                    
+                    let request = UNNotificationRequest(identifier: message.id, content: content, trigger: nil /* now */)
+                    center.add(request) { (error) in
+                        if let error = error {
+                            Log.e(self.tag, "Unable to create notification", error)
+                        }
+                    }
+                }
+            }
+        }
+        completionHandler(.newData)
+    }
+    
     func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
         let token = deviceToken.map { data in String(format: "%02.2hhx", data) }.joined()
         Messaging.messaging().apnsToken = deviceToken

ntfy/Persistence/Store.swift

@@ -70,6 +70,10 @@ class Store: ObservableObject {
         return try? context.fetch(fetchRequest).first
     }
     
+    func getSubscriptions() -> [Subscription]? {
+        return try? context.fetch(Subscription.fetchRequest())
+    }
+    
     func delete(subscription: Subscription) {
         context.delete(subscription)
         try? context.save()

ntfy/Persistence/SubscriptionManager.swift

@@ -25,20 +25,26 @@ struct SubscriptionManager {
     }
     
     func poll(_ subscription: Subscription) {
+        poll(subscription) { _ in }
+    }
+    
+    func poll(_ subscription: Subscription, completionHandler: @escaping ([Message]) -> Void) {
         Log.d(tag, "Polling from \(subscription.urlString())")
         ApiService.shared.poll(subscription: subscription) { messages, error in
             guard let messages = messages else {
                 Log.e(tag, "Polling failed", error)
+                completionHandler([])
                 return
             }
             Log.d(tag, "Polling success, \(messages.count) new message(s)", messages)
             if !messages.isEmpty {
-                DispatchQueue.main.async {
+                DispatchQueue.main.sync {
                     for message in messages {
                         store.save(notificationFromMessage: message, withSubscription: subscription)
                     }
                 }
             }
+            completionHandler(messages)
         }
     }
 }

ntfy/Views/SubscriptionAddView.swift

@@ -7,6 +7,8 @@ struct SubscriptionAddView: View {
     
     @EnvironmentObject private var store: Store
     @State private var topic: String = ""
+    @State private var useAnother: Bool = false
+    @State private var baseUrl: String = ""
     
     private var subscriptionManager: SubscriptionManager {
         return SubscriptionManager(store: store)
@@ -24,6 +26,14 @@ struct SubscriptionAddView: View {
                             .disableAutocapitalization()
                             .disableAutocorrection(true)
                     }
+                    Section {
+                        Toggle("Use another server", isOn: $useAnother)
+                        if useAnother {
+                            TextField("Server URL, e.g. https://ntfy.example.com", text: $baseUrl)
+                                .disableAutocapitalization()
+                                .disableAutocorrection(true)
+                        }
+                    }
                 }
             }
             .navigationTitle("Add subscription")
@@ -61,8 +71,9 @@ struct SubscriptionAddView: View {
     }
     
     private func subscribeAction() {
+        let baseUrl = (useAnother) ? baseUrl : Config.appBaseUrl
         DispatchQueue.global(qos: .background).async {
-            subscriptionManager.subscribe(baseUrl: Config.appBaseUrl, topic: sanitize(topic: topic))
+            subscriptionManager.subscribe(baseUrl: baseUrl, topic: sanitize(topic: topic))
         }
         isShowing = false
     }
@@ -71,3 +82,14 @@ struct SubscriptionAddView: View {
         isShowing = false
     }
 }
+
+
+struct SubscriptionAddView_Previews: PreviewProvider {
+    @State static var isShowing = true
+    
+    static var previews: some View {
+        let store = Store.preview
+        SubscriptionAddView(isShowing: $isShowing)
+            .environmentObject(store)
+    }
+}