Pass Variable from iOS to watchOS - ios

In my viewController, I have a varible for an AVAudioPlayer
var audioPlayer = AVAudioPlayer()
I want to acess this varible in my watchKit app so that I can play and pause the AVAudioPlayer from the watchKit app. Like
audioPlayer.play()
audioPlayer.pause()
How can I acess this variable from my watchKit app? Thanks for the help! I'm using Swift 3 and Xcode 8.

Since watchOS 2, you can't use AppGroups to share data directly between your iOS app and the WatchKit app.
Your only option to communicate between the two is the WatchConnectivity framework. Using WatchConnectivity, you can signal the iOS app using instant messaging to start/stop playing. On iOS in your AppDelegate implement something like this:
func session(_ session: WCSession, didReceiveMessage message: [String : Any], replyHandler: #escaping ([String : Any]) -> Void) {
if let content = message["play"] as? [String:Any] {
audioPlayer.play()
replyHandler(["startedPlaying":true])
} else if let content = message["pause"] as? [String:Any] {
audioPlayer.pause()
replyHandler(["pausedMusic":true])
}
}
And in your Watch app you need to send messages with the content specified in your AppDelegate's session(_:didReceiveMessage:replyHandler:). If you don't need to send a response back to the Watch app, you can just use session(_:didReceiveMessage:) and get rid of the replyHandler part.

Related

iPhone app isn't waking in the background when WCSession's sendMessage is fired

I'm making an app for Apple Watch that needs to wake the iPhone's counterpart app which loads a site via a WKWebView, takes a snapshot, and sends the image back.
It works perfectly when the iPhone app is on-screen, intermittently when it's running in the background, but not at all when the app is completely closed.
Is there any way to get the iPhone app to wake up in the background with WCSession's sendMessage? I've read that it's meant to but I haven't been able to get it working. Is it because the iPhone app doesn't send a reply to the initial message sent by the watch (the file that the iPhone sends back has to wait for the WKWebView to finish loading, so it can't be sent back in replyHandler)? Is there a plist setting I forgot to toggle?
The current workflow of this code is as follows:
On the Apple Watch, the user taps a button which triggers the already activated WCSession's sendMessage function in ExtensionDelegate.
The iPhone app receives it using the WCSession that it activated in AppDelegate.
In didRecieve, the iPhone app feeds a URL into a WKWebView and starts loading it.
In WKWebView's didFinish function, it takes a snapshot of the site and sends it back to the watch with transferFile.
The watch receives the snapshot and passes it back to the right ViewController.
All of these steps have been tested and verified to work while both apps are on-screen, but as soon as the iPhone enters the background or has its counterpart app closed, this workflow becomes very unstable.
The relevant code is below:
After the user presses the button, the ViewController fires a notification to ExtensionDelegate with the information to transmit over WCSession.
ExtensionDelegate (sending the message):
#objc func transmit(_ notification: Notification) {
// The paired iPhone has to be connected via Bluetooth.
if let session = session, session.isReachable {
session.sendMessage(["SWTransmission": notification.userInfo as Any],
replyHandler: { replyData in
// handle reply from iPhone app here
print(replyData)
}, errorHandler: { error in
// catch any errors here
print(error)
})
} else {
// when the iPhone is not connected via Bluetooth
}
}
The iPhone app (should, but doesn't) wakes up and activates the WCSession:
fileprivate let session: WCSession? = WCSession.isSupported() ? WCSession.default : nil
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
// Override point for customization after application launch.
session?.delegate = self
session?.activate()
webView.navigationDelegate = self
webView.scrollView.contentInsetAdjustmentBehavior = .never
return true
}
The iPhone app receives the message in AppDelegate, and activates the WKWebView. Note that there isn't a configured reply. Could this be the cause of my issue?
func session(_ session: WCSession, didReceiveMessage message: [String : Any], replyHandler: #escaping ([String : Any]) -> Void) {
DispatchQueue.main.async { [self] in
let dictionary = message["SWTransmission"] as! [String: Any]
let link = URL(string: dictionary["URL"] as! String)!
let request = URLRequest(url: link)
webView.frame = CGRect(x: 0, y: 0, width: Int(((dictionary["width"] as! Double) * 1.5)), height: dictionary["height"] as! Int)
webView.load(request)
}
}
[Still in AppDelegate] After the site is loaded, didFinish (should) gets activated, where it takes a snapshot and sends the file back to the watch via transferFile.
func getDocumentsDirectory() -> URL {
let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
return paths[0]
}
func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
webView.takeSnapshot(with: nil) { [self] (image, error) in
let filename = getDocumentsDirectory().appendingPathComponent("webImage.jpg")
if let data = image!.jpegData(compressionQuality: 0.8) {
try? data.write(to: filename)
}
self.session?.transferFile(filename, metadata: nil)
}
}
The Apple Watch receives the file in ExtensionDelegate and sends it back to the relevant ViewController:
func session(_ session: WCSession, didReceive file: WCSessionFile) {
DispatchQueue.main.async { [self] in
do {
NotificationCenter.default.post(name: NSNotification.Name("openSite"), object: nil, userInfo: ["imageURL": file.fileURL] as [String: Any])
} catch {
print(error)
}
}
}
Thank you very much for your help!
I do not have experience working on WatchOS, but I took a look at the documentation for WCSession and it seems that what you are observing exactly matches the expected behaviour.
You mention
"It works perfectly when the iPhone app is on-screen, intermittently when it's running in the background, but not at all when the app is completely closed"
The Apple documentation for WCSession states
When both session objects are active, the two processes can communicate immediately by sending messages back and forth. When only one session is active, the active session may still send updates and transfer files, but those transfers happen opportunistically in the background.
These two align perfectly.
When the app is on-screen, both session objects are apparently active, and as per your observation under this scenario you see the communication happening everytime.
When the app is in background, the session object on the app side appears to be not active, and the transfer would take place 'opportunistically', which is in-line with you observation that the communication occurs intermittently.
When the the app is completely closed, it cannot be launched by the system under any circumstance as far as I know, and this is also in-line with your observation that in-this situation the communication never happens.
Unless you've already read through the WCSession documentation, I would suggest that you go through it. I see that you are checking for WCSession's isReachable property, however, another important property that is mentioned on the documentation page is activationState. It may be worth checking the value of this property before initiating the communication.

Can the watch app receive background info even if the app is in the background?

I cannot figure out how to make updateApplicationContext data arrive on the watch before the watch app is foregrounded. It seems to work only when the watch app is foregrounded.
How can the watch receive files while in the background?
This is what I've been trying to accomplish:
iOS code:
func sendDataToWatch() {
if WCSession.isSupported() {
do {
try WCSession.default.updateApplicationContext(["key":value])
} catch {
print("ERROR: \(error)")
}
}
}
Watch code:
func session(_ session: WCSession, didReceiveApplicationContext
applicationContext:[String : Any]) {
//handle data when it arrives
}
I noticed that the WatchConnectivity was provided with a handler function. Is this something I should set up to be able to handle background connectivity while the Watch App is backgrounded or not even launched?
func handle(_ backgroundTasks: Set<WKRefreshBackgroundTask>) {
// Sent when the system needs to launch the application in the background to process tasks. Tasks arrive in a set, so loop through and process each one.
for task in backgroundTasks {
// Use a switch statement to check the task type
switch task {
case let backgroundTask as WKApplicationRefreshBackgroundTask:
// Be sure to complete the background task once you’re done.
backgroundTask.setTaskCompletedWithSnapshot(false)
default:
// make sure to complete unhandled task types
task.setTaskCompletedWithSnapshot(false)
}
}
}
According to apple you can send data from iPhone to Apple Watch using SendMessage while session is reachable.
https://developer.apple.com/documentation/watchconnectivity/wcsession/1615687-sendmessage
Calling this method from your WatchKit extension while it is active
and running wakes up the corresponding iOS app in the background and
makes it reachable.
You can use below methods to send data from the iPhone to Apple Watch
Swift 2.2
let msg = ["IPrequest":"IsLogin"]
WCSession.defaultSession().sendMessage(msg, replyHandler: { (replyDict) in
print(replyDict)
}, errorHandler: { (error) in
print(error)
})
Received dictionary using below method
Swift 2.2
func session(session: WCSession, didReceiveMessage message: [String : AnyObject], replyHandler: ([String : AnyObject]) -> Void)
{
dispatch_async(dispatch_get_main_queue()) { () -> Void in
print("Response:\(message)")
}
}
I have implemented above solution in one of the my project.
Hope it will help you!

AVAudioSession always returns the same outputVolume

I have an watchOS app that request the current volume from the iPhone parent app via:
session?.sendMessage(["getVolume":1], replyHandler: {
replyDict in
if let currentVolume = replyDict["currentVolume"] as? Float{
NSLog("Current volume received from phone with value: \(currentVolume)")
}
}, errorHandler: {
(error) -> Void in
NSLog("Error: :\(error)")
// iOS app failed to get message. Send it in the background
//self.session?.transferUserInfo(["getVolume":1])
})
The iPhone app handles it like this:
func session(_ session: WCSession, didReceiveMessage message: [String : Any], replyHandler: #escaping ([String : Any]) -> Void) {
NSLog("Received a message")
if let _ = message["getVolume"] as? Int{
replyHandler(["currentVolume":AVAudioSession.sharedInstance().outputVolume])
}
else{
replyHandler([:])
}
}
This always returns the same outputVolume the phone had on the first request.
I investigated several things like if there is some kind of caching for the background request but it is always a new call that returns the new value.
Is there any workaround to get system volume with a different way or maybe a solution how to get this to work with AVAudioSession?
This isn't an issue with the WatchKit or watchOS per se, as I've experienced this in a regular iOS application.
I had to activate my app's audio session in order to observe the change in volume:
try? AVAudioSession.sharedInstance().setActive(true)

How trigger background process from Watch on iPhone (trigger: Watch)?

I'd like to add to my Watch app functionality which send to iPhone app a Local Notification (while iPhone app is on the background or iPhone is locked).
I know how to create Local Notification itself.
What Im asking for is way, how to trigger background process (which contains also Local Notification) on iPhone by (for example) tapping on button on Apple Watch.
WKInterfaceController.openParentApplication is the official way to communicate with the iPhone. Documentation.
You pass parameters in the userInfo dictionary and retrieve results via the reply block.
On the iPhone the request is handled by appDelegate's handleWatchKitExtensionRequest method. Documentation
Code in my InterfaceController.swift:
#IBAction func btn() {
sendMessageToParentApp("Button tapped")
}
// METHODS #2:
func sendMessageToParentApp (input:String) {
let dictionary = ["message":input]
WKInterfaceController.openParentApplication(dictionary, reply: { (replyDictionary, error) -> Void in
if let castedResponseDictionary = replyDictionary as? [String:String], responseMessage = castedResponseDictionary["message"] {
println(responseMessage)
self.lbl.setText(responseMessage)
}
})
}
Next i made new method in my AppDelegate.swift:
func application(application: UIApplication, handleWatchKitExtensionRequest userInfo: [NSObject : AnyObject]?, reply: (([NSObject : AnyObject]!) -> Void)!) {
if let infoDictionary = userInfo as? [String:String], message = infoDictionary["message"] {
let response = "iPhone has seen this message." // odešle se string obsahující message (tedy ten String)
let responseDictionary = ["message":response] // tohle zase vyrobí slovník "message":String
NSNotificationCenter.defaultCenter().postNotificationName(notificationWatch, object: nil)
reply(responseDictionary)
}
}
As you can see I use Notification to get iOS app know that button has been tapped. In ViewController.swift I have Notification Observer and function which is executed every time observer catch notification that user tapped on button on watch ("notificationWatch" is global variable with notification key). Hope this will help to anybody.

How to open the app when someone clicks something on an Apple Watch app?

I am making an Apple Watch app. One of the buttons will open the iphone app connected to the watch app.
What code do I use to do this?
I don't know what to even try?
Note: I am using swift for this project.
WatchKit doesn't include the ability to open the host iOS app in the foreground. The best you can do is open it in the background using openParentApplication:reply:.
If you need the user to do something in your iOS app, consider making use of Handoff.
It is not possible to activate an inactive iPhone app from the Watch. It is, however, possible to call the iPhone app to perform a task or to ask for data. See here: Calling parent application from Watch app
You can only open the iPhone app in the background by the following method:
Swift:
openParentApplication([ParentApp], reply:[Reply])
Objective-C:
openParentApplication:reply:
There is no ability to open the parent app in the foreground.
Note: To send data to iOS app in the background, use the first method.
Note: According to bgilham,
If you need the user to do something in your iOS app, consider making use of Handoff.
If you need to open your parent app in the foreground, use Handoff!
https://developer.apple.com/handoff/
Example:
Somewhere shared for both:
static let sharedUserActivityType = "com.yourcompany.yourapp.youraction"
static let sharedIdentifierKey = "identifier"
on your Watch:
updateUserActivity(sharedUserActivityType, userInfo: [sharedIdentifierKey : 123456], webpageURL: nil)
on your iPhone in App Delegate:
func application(application: UIApplication, willContinueUserActivityWithType userActivityType: String) -> Bool {
if (userActivityType == sharedUserActivityType) {
return true
}
return false
}
func application(application: UIApplication, continueUserActivity userActivity: NSUserActivity, restorationHandler: ([AnyObject]!) -> Void) -> Bool {
if (userActivity.activityType == sharedUserActivityType) {
if let userInfo = userActivity.userInfo as? [String : AnyObject] {
if let identifier = userInfo[sharedIdentifierKey] as? Int {
//Do something
let alert = UIAlertView(title: "Handoff", message: "Handoff has been triggered for identifier \(identifier)" , delegate: nil, cancelButtonTitle: "Thanks for the info!")
alert.show()
return true
}
}
}
return false
}
And finally (this step is important!!!): In your Info.plist(s)

Resources