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watchOS: Complications
Note: At the time of writing, watchOS has a bug—verified by Apple—that sometimes prevents your app from registering for PushKit notifications. Apple told me it believes it has determined the root cause. However, there’s no ETA on when the fix will be available.
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While background tasks and background URL downloads work well, they’re not always the best solution.
PushKit registration
Complication push notifications are a bit different from standard remote push notifications.
import Foundation
import PushKit
final class PushNotificationProvider: NSObject {
}
final class PushNotificationProvider🟩: NSObject {
}
let registry = PKPushRegistry(queue: .main)
override init() {
super.init()
registry.delegate = self
}
registry.desiredPushTypes = [.complication]
}
PKPushRegistryDelegate
Now to start implementing the delegate, open an extension and adopt PKPushRegistryDelegate.
extension PushNotificationProvider: PKPushRegistryDelegate {
}
func pushRegistry(
_ registry: PKPushRegistry,
didUpdate pushCredentials: PKPushCredentials,
for type: PKPushType
) {
}
let token = pushCredentials.token.reduce("") {
$0 + String(format: "%02x", $1)
}
print(token)
// Send token to your server.
Receiving a push notification
Now that things are set up, we can handle receiving a PushKit notification with another delegate method:
func pushRegistry(
_ registry: PKPushRegistry,
didReceiveIncomingPushWith payload: PKPushPayload,
for type: PKPushType
) async {
}
print(payload.dictionaryPayload)
await ExtensionDelegate.updateActiveComplications()
}
Initialize the provider
The only step left is to initialize the Push Notification Provider, which we can do in UpdatesApp.swift.
private let push = PushNotificationProvider()
apns-topic
Note: There’s one special consideration when sending a PushKit notification. The apns-topic header should be the name of your extension’s bundle identifier with
.complicationappended to it.
Testing
Other than the extra text you need to add to the apns-topic, there’s nothing special about testing push notifications, here. If you’re able to register your app for PushKit notifications, you can test it the same way you would do with an iPhone.