How to trigger communication with backend from Apple Watch? - ios

I want to click on a push notification on my Apple Watch trigger communication with backend and show the results in a table on my Apple Watch.
I know how to show the result in a table on my Apple Watch. I also know the openParentApplication:reply: method.
But if I want to trigger my backend communication in application:handleWatchKitExtensionRequest:reply: I get a error that reply() is never called. It seems that iOS kill this method if it takes to much time.
If I test application:handleWatchKitExtensionRequest:reply: with a hard coded dictionary with only one entry, all works fine.
That is the recommended way to do this?
In my opinion I should do something in NotificationController.swift in didReceiveRemoteNotification method and app group but how can I trigger the backend communication on my iPhone?
UPDATE:
Part of my code in AppDelefate.swift:
func application(application: UIApplication!, handleWatchKitExtensionRequest userInfo: [NSObject : AnyObject]!, reply: (([NSObject : AnyObject]!) -> Void)!) {
var workaround: UIBackgroundTaskIdentifier?
workaround = UIApplication.sharedApplication().beginBackgroundTaskWithExpirationHandler({
UIApplication.sharedApplication().endBackgroundTask(workaround!)
})
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, Int64(2 * NSEC_PER_SEC)), dispatch_get_main_queue(), {
UIApplication.sharedApplication().endBackgroundTask(workaround!)
})
var realBackgroundTaks: UIBackgroundTaskIdentifier?
realBackgroundTaks = UIApplication.sharedApplication().beginBackgroundTaskWithExpirationHandler({
reply(nil)
UIApplication.sharedApplication().endBackgroundTask(realBackgroundTaks!)
})
let testDict = ["Hello" : "World"]
reply(testDict)
UIApplication.sharedApplication().endBackgroundTask(realBackgroundTaks!)
}
This code works fine.
But if I change testDict to the backend communication code this method will killed.

Today I found the solution for my problem. You can not pass custom objects in the reply dictionary, you have to use primitive types.
The splution is described on the following page from Kristina Thai.
http://realm.io/news/watchkit-mistakes/

You'll need to start a background task on the iPhone to ensure your app isn't killed in the background before your API request can complete. I've shared some resources in a similar answer here: https://stackoverflow.com/a/29848521/3704092

Related

How to resolve these CloudKit Background Task Warnings

I have a functioning iOS app that is producing some troubling warning messages and I'd like to resolve them.
From the console:
Background Task 37 ("CoreData: CloudKit Import"), was created over 30 seconds ago. In applications running in the background, this creates a risk of termination. Remember to call UIApplication.endBackgroundTask(_:) for your task in a timely manner to avoid this.
This warning is repeated periodically, however, each time with a different Task Id. I presume that if I can capture the Task Id, I could figure where to call
UIApplication.endBackgroundTask(_:)
I do not know if it's possible to obtain the Task Id. I do have a notification observer set to check for data changes. I'd prefer not to remove that.
func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [NSObject : AnyObject]) {
OperationQueue.main.addOperation({ () -> Void in
self.fetchProjects()
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Core Data fetch request with WatchConnectivity

I'm currently trying to get CoreData data from my iOS app to the watchOS extension. I'm using the WatchConnectivity Framework to get a dictionary via the sendMessage(_ message: [String : Any], replyHandler: (([String : Any]) -> Void)?, errorHandler: ((Error) -> Void)? = nil) function. The basic connection is working fine. The iOS app is reachable and if I try to reply a sample dictionary everything is working.
So far so good, but as I start doing a fetch request on the iOS app in background, the Watch App never receives data. After a while I just get this error: Error while requesting data from iPhone: Error Domain=WCErrorDomain Code=7012 "Message reply took too long." UserInfo={NSLocalizedFailureReason=Reply timeout occurred., NSLocalizedDescription=Message reply took too long.}
If I open the iOS app on the iPhone and relaunch the Watch App the reply handler is getting the result. But forcing the user to actively open the iOS app on the iPhone is useless.
Can someone explain why this is happen? And what's the right way to do it? App Groups seem to be obsolete since watchOS 2.
I'm using Swift 4 btw…
On Apple Watch:
import WatchConnectivity
class HomeInterfaceController: WKInterfaceController, WCSessionDelegate {
// (…)
func session(_ session: WCSession, activationDidCompleteWith activationState: WCSessionActivationState, error: Error?) {
session.sendMessage(["request": "persons"],
replyHandler: { (response) in
print("response: \(response)")
},
errorHandler: { (error) in
print("Error while requesting data from iPhone: \(error)")
})
}
On iPhone:
import CoreData
import WatchConnectivity
class ConnectivityHandler: NSObject, WCSessionDelegate {
var personsArray:[Person] = []
// (…)
func session(_ session: WCSession, didReceiveMessage message: [String : Any], replyHandler: #escaping ([String : Any]) -> Void) {
// only using the next line is working!
// replyHandler(["data": "test"])
if message["request"] as? String == "persons" {
fetchAllPersons()
var allPersons: [String] = []
for person in personsArray {
allPersons.append(person.name!)
}
replyHandler(["names": allPersons])
}
}
// this seems to be never executed (doesn't matter if it's in an extra function or right in the didReceiveMessage func)
func fetchAllPersons() {
do {
// Create fetch request.
let fetchRequest: NSFetchRequest<Person> = Person.fetchRequest()
// Edit the sort key as appropriate.
let sortDescriptor = NSSortDescriptor(key: #keyPath(Person.name), ascending: true)
fetchRequest.sortDescriptors = [sortDescriptor]
personsArray = try DatabaseController.getContext().fetch(fetchRequest)
} catch {
fatalError("Failed to fetch: \(error)")
}
}
After looking into this problem I found the solution by myself. The problem was that I'm using the sendMessage(_:replyHandler:errorHandler:) protocol. This is only used for transferring data when both apps are active.
Use the sendMessage(_:replyHandler:errorHandler:) or sendMessageData(_:replyHandler:errorHandler:) method to transfer data to a reachable counterpart. These methods are intended for immediate communication between your iOS app and WatchKit extension. The isReachable property must currently be true for these methods to succeed.
If you want to transfer data in the background you have to use updateApplicationContext(_:) or transferUserInfo(_:) depending on your needs. That's exactly what I needed!
Use the updateApplicationContext(_:) method to communicate recent state information to the counterpart. When the counterpart wakes, it can use this information to update its own state. For example, an iOS app that supports Background App Refresh can use part of its background execution time to update the corresponding Watch app. This method overwrites the previous data dictionary, so use this method when your app needs only the most recent data values.
Use the transferUserInfo(_:) method to transfer a dictionary of data in the background. The dictionaries you send are queued for delivery to the counterpart and transfers continue when the current app is suspended or terminated.
Now if the iPhone App counterpart opens the ApplicationContext or UserInfo queue is passed trough and I can add the data to my core data library.
Sadly, most WatchConnectivity methods have a time limit (as told you by the error) and it seems your CoreData request is taking too much time and hence it exceeds the time limit. According to this Q&A it seems that you need to take specific precautions for doing CoreData queries in the background, so that might be the cause for your issue.
However, for best user experience I would recommend you to stop using CoreData and the WatchConnectivity framework, since the latter requires your iOS app to be running at least in the background, hence making the watchOS app dependent on the state of the iOS app and degrading the user experience on watchOS. I'd recommend you switch to Realm, since Realm supports watchOS fully and hence your watchOS app can be fully independent from your iOS app, making the user experience more fluid, since the user won't have to start the iOS app and wait for the data transmission through BLE using the WatchConnectivity framework.

iOS: Why is fetch background function never fully executed?

My code in appdelegate for background fetch is never fully run. I have the background fetch option turned on and the plist updated.
I trigger the code by pressing Debug > Simulate Background Fetch
This is the code
func application(application: UIApplication, performFetchWithCompletionHandler completionHandler: (UIBackgroundFetchResult) -> Void) {
User.getNotifications(User.getUserDetails()["id"].string!, callback: {(notifications) in
//update notification badge count
notificationBadgeCount = X
})
}
'User.getNotifications' looks like this
getNotifications(id: String, callback...){
alamofire.request(.GET....){ jsonResponse in
//GETS HERE
callback(jsonResponse)
}
}
When triggering the simulated background fetch, the alamofire GET request is sent and data is returned (I've checked the server and the call is sent), however, the app seems to suspend at (//GETS HERE) in the getNotifications call, so the rest the code in the background fetch (//update notification badge count) is never run.
The code seems to time out. I'm supposed to get 30s however it seems to time out in 5s or something.
Any idea why that section of code isn't executed?
NOTE: If I re-open the app manually, then the rest of the code executes.
performFetch has an incoming function called completionHandler. You must call that function to complete the fetch and stop the countdown clock. You are not doing that and you thus are timing out and the app is suspended.

Call ExtensionDelegate to create/refresh data for Complication

All my data creation is done in the ExtensionDelegate.swift.
The problem is ExtensionDelegate.swift doesn't get called before the function getCurrentTimelineEntryForComplication in my ComplicationController.swift.
Any ideas? Here is my code and details:
So my array extEvnts is empty in my ComplicationController.swift:
func getCurrentTimelineEntryForComplication(complication: CLKComplication, withHandler handler: ((CLKComplicationTimelineEntry?) -> Void)) {
let extEvnts = ExtensionDelegate.evnts
}
Because my ExtensionDelegate.swift hasn't gotten called yet, which is what creates the data for the array:
class ExtensionDelegate: NSObject, WKExtensionDelegate, WCSessionDelegate {
private let session = WCSession.defaultSession()
var receivedData = Array<Dictionary<String, String>>()
static var evnts = [Evnt]()
func session(session: WCSession, didReceiveUserInfo userInfo: [String : AnyObject]) {
if let tColorValue = userInfo["TeamColor"] as? String, let matchValue = userInfo["Matchup"] as? String {
receivedData.append(["TeamColor" : tColorValue , "Matchup" : matchValue])
ExtensionDelegate.evnts.append(Evnt(dataDictionary: ["TeamColor" : tColorValue , "Matchup" : matchValue]))
} else {
print("tColorValue and matchValue are not same as dictionary value")
}
}
func applicationDidFinishLaunching() {
// Perform any final initialization of your application.
if WCSession.isSupported() {
session.delegate = self
session.activateSession()
}
}
}
EDIT:
Per Apple, it looks like this has something to do with it, but for some reason I have no idea how to actually implement it because I'm not able to call mydelegate.evnts:
// Get the complication data from the extension delegate.
let myDelegate = WKExtension.sharedExtension().delegate as! ExtensionDelegate
var data : Dictionary = myDelegate.myComplicationData[ComplicationCurrentEntry]!
So I've tried something like this, and still can't get it working because I'm still getting no data:
func someMethod() {
let myDelegate = WKExtension.sharedExtension().delegate as! ExtensionDelegate
let dict = ExtensionDelegate.evnts
print("ExtensionDel.evnts: \(dict.count)")
}
Useful question that helped me here
In the function requestedUpdateDidBegin() you can update the information that you will display in your complication. So in this method you may make a call to your parent app using a WatchConnectivity method like sendMessage:replyHandler:errorHandler: to receive new information.
You can use NSUserDefaults to store your imperative data that will be used in your ComplicationController, then load this information from NSUserDefaults for your complication. I store this data in user defaults so that I always have old data to display in case the new data fails to load.
TL/DR: Have the extension tell ClockKit to update the complication after the data is received.
First issue:
So my array extEvnts is empty in my ComplicationController.swift ... Because my ExtensionDelegate.swift hasn't gotten called yet, which is what creates the data for the array
Your array is empty because the data hasn't been received at that point.
You can't (get the complication controller to) force the watch (extension) to receive data which may not have even been transmitted yet.
If you look at the WCSession Class Reference, transferUserInfo queues data to be transferred in the background, when the system decides it's a good time to send the info.
Remember that background transfers are not be delivered immediately. The system sends data as quickly as possible but transfers are not instantaneous, and the system may delay transfers slightly to improve power usage. Also, sending a large data file requires a commensurate amount of time to transmit the data to the other device and process it on the receiving side.
Second issue:
You're trying to combine updating your app and your complication based on data sent from your phone. But your app and your complication don't necessarily run together. It's not surprising or unexpected that the watch updates the complication before any data has even been sent/received. The App Programming Guide for watchOS mentions that
Complications exist entirely in the WatchKit extension. Their user interface is not defined in the Watch app. Instead, it is defined by an object implementing the CLKComplicationDataSource protocol. When watchOS needs to update your complication, it launches your WatchKit extension. However, the Watch app’s executable is not launched.
There's no mechanism for the complication controller to say, "Wait, I'm not ready to provide an update. The complication controller can't wait on (or as mentioned, force) the watch extension to receive data.
It's only responsibility is to immediately return data based on what's currently available to it. If there's no data, it must return an empty timeline.
Approaching this problem:
You shouldn't necessarily think of app updates and complication updates as the same thing. The first is not budgeted, but the second is budgeted. If you update your complication too often, you may exceed your daily budget, and no further updates will occur for the remainder of the day.
Complications aren't meant to be frequently updated. Complications should provide as much data as possible during each update cycle. You shouldn't ask the system to update your complication within minutes. You should provide data to last for many hours or for an entire day.
Having covered that, you could wait until your extension has received data, then can ask ClockKit to extend your timeline, so new entries can be added to it. extendTimelineForComplication: is documented in the CLKComplicationServer Class reference.
As an aside, if your data is urgent, you should use transferCurrentComplicationUserInfo. It's a high-priority message, which is placed at the head of the queue, and the extension is woken up to receive it. See this answer for a comparison between it and transferUserInfo.
You also could setup a singleton to hold your data which the watch app and complication controller both use. This was mentioned in an answer to an old question of yours, and also recommended by an Apple employee on the developer forums.

WKInterfaceController.openParentApplication is delayed on real device?

I've been tracking this bug for days and finally realized the issue is that there is an actual delay with WKInterfaceController.openParentApplication. I am not referring to the callback in the Apple Watch, but the AppDelegate event in the iPhone.
Here's what I'm doing in the Apple Watch:
override func awakeWithContext(context: AnyObject?) {
var userInfo = [
"test": 123
]
WKInterfaceController.openParentApplication(userInfo, reply: nil)
}
Then in the iPhone, I'm doing this in AppDelegate:
func application(application: UIApplication, handleWatchKitExtensionRequest userInfo: [NSObject : AnyObject]?, reply: (([NSObject : AnyObject]!) -> Void)!) {
let test = userInfo["test"]
// Do something
}
The problem is when I call WKInterfaceController.openParentApplication, there is a 2 or 3 second delay before the handleWatchKitExtensionRequest event is triggered in the iPhone. This is problematic if the user performs an action on their watch really quickly and puts down their arm right after. I can't assume the user is going to hold up their arm for 3 seconds until the watch sends the command.
Here's the catch: if the user wakes up the watch, the command still doesn't get sent to the iPhone.. UNTIL the user opens up the original app that sent the WKInterfaceController.openParentApplication. I don't think any of this would be a problem without this catch, the command should be queued until the watch is awakened, not awakened AND reopen the app.
Any workaround that can be done for this? I plan on logging this as a bug, but wanted to see if anyone has any thoughts or experience with this?

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