watchkit | Sharing Data with WatchKit Examples

I have a watchapp that receives parent view model (nested view model) data from iPhone via json/file transfer. I am using "Communicator" library by @KaneCheshire.

The data flow is

1. Watch App launches - loading empty Parent View Model (ReceivedDayProgViewModel) into the app and showing activity indicator in WatchLoadingView.
2. WatchLoadingView set-up observer to receive actual json data/file from iPhone
3. WatchLoadingView's observer receives actual json data, decodes them into ParentViewModel object (ReceivedDayProgViewModel)

After step 3, I am having difficulty actually assigning the decoded object to the initially empty Parent View Model (ReceivedDayProgViewModel). There is a error message saying "**Cannot assign to property: 'receivedDayProgramVM' is a get-only property**"

So I did look up the error and have an idea that my parent View Model is actually a "computed-property" instead of stored property - How do I resolve this build issue - cannot assign to property: 'date' is a get only property But I am still struggling to add codes to ensure "set/write" function is embedded in the Parent View Model(ReceivedDayProgViewModel).

Would appreciate any guidance/advice on how I can change my code to allow "set/write" operation in Parent View Model (ReceivedDayProgViewModel) so below step can be fulfilled.

1. Assign decoded object (let ReceivedDayProgViewModel = try! decoder.decode(ReceivedDayProgViewModel.self, from: ReceivedDayProgVMData)) (with values/data from iPhone) into the @StateObject in ContentView (receivedDayProgramVM)

Parent View Model

I'm implementing a background app refresh for a watch app. To initiate the background refresh, I call the function below during my model initiation when ContentView is loaded:

I already created my Apple Watch music app with background sound in SwiftUI. I want to somehow present NowPlayigView. The only thing I found on the Apple Developer website about it is in the attached picture. Maybe the solution is very simple, but I can't find it. Please help. Image

https://developer.apple.com/documentation/watchkit/storyboard_support/adding_a_now_playing_view

We have developed a Watch App for our React-Native IOS app using SwiftUI. After the the integrations are completed, we've tried to upload the build to TestFlight for testing purposes. In the process, since enabling bitcode is mandatory for WatchOS apps, it is enabled through Project Target -> Build Settings -> Build Options -> Enable Bitcode : Yes (And also tried to enable bitcode for Pods target). However, there is no other option to enable bitcode in the Watch Targets (both watch app and watchkit extension).

When we tried to upload the build to TestFlight, it got rejected with the error code ITMS-90496: Invalid Executable - The executable "{ProjectName}/Watch App WatchKit Extension.appex/WatchKit Extension" does not contain bitcode.

I have also read that in order to make the whole project bitcode enabled, you need to make sure that the libraries are also bitcode compatible. And since the app is a React-Native app, it contains a lot of 3rd party libraries. If anyone who tried to add a Watch App to an existing React-Native project and managed to upload it to TestFlight can help us during the process, it would be really helpful.

I am facing an issue trying to convert message from apple watch's WC session [String: Any] as I am customizing a sample project that retrieves heart rate from apple watch and send it to iPhone. I am hoping that I can get some help as I am already struggling with watchconnectivity for 3 days.

I do see that I am receiving the message properly from Apple Watch and I am close to utilize the message received to update heart rate at iOS app side. But I think the "guard let" statement is causing the didReceiveMessage function to stop half way.

I am not sure, but I think if I can "unwrap" the message ["rate": 61] into 61 in double format, I should be able to pass the guard let function and get this function working.

On top of that I am seeing another error saying "NO with WCErrorCodeDeliveryFailed", but I am not sure why this is being populated as I already implemented suggested solutions from other SO answers. But I think this error is redundant/unrelated to above error message.

Would appreciate help.

According to the docs, sending sendMessage from the WatchKit app will wake the iPhone app if it is inactive.

I would like to know the differences between such a wakeup app startup and a normal one. Surely a background process has a lot of differences to a normal foreground app. However, I could not find a thorough documentation on the subject.

Here's what I found so far:

• Since such a "wakeup" is not a normal app startup, I expect didFinishLaunchingWithOptions to receive a special launchOptions key. After all, the user did not start the app on the home screen, so there should be an indication in launchOptions. But when I tried it out, launchOptions was nil. Doesn't that contradict the docs?
• I also thought there should be differences because there is no UI present in a background process. So perhaps [UIScreen mainScreen] might be nil. But there seems to be no difference in mainScreen in the background process. In my AppDelegate.m, the code that creates the main window seems to run exactly the same way as in the foreground process.
• I also expect that there are limits to the background process. Since the user did not actively start the process, I'm pretty sure that it cannot run for an infinite amount of time. Maybe there are also stricter memory limits.
• Is there a way I can debug such a background process in XCode? Can I tell XCode "wait until the app runs on the iPhone", such that the debugger gets attached as soon as the app runs?
• I also tried this in a React Native app. The Objective-C code in AppDelegate.m seemed to run exactly the same way, regardless of background or foreground process. However, the whole Javascript part of the app did not run (which is kind of expected, because in a background process, we do not need any React UI). But there must be a difference in the process that causes the Javascript part to not run.

Please don't consider this question to be about "more than one question". The question of this post is quite clear: I want to know all the differences between a didReceiveMessage background process and a normal one. In the enumeration above, I just listed all the differences I would expect or that I have encountered so far, and the lack of documentation on those topics.

Since most devices today have a CPU and a GPU, the usual advice for programmers wishing to do animated vector graphics (like making a circle grow or move around) is to define the graphical item once and then use linear transformations to animate it. This way, (on most platforms and frameworks) the GPU can do the animation work, because rasterization with linear transformations can be done very fast on a GPU. If the programmer chooses to draw each frame on the CPU, it would most likely be much slower and consume more energy.

I understand that the Watch is not a device you want to overload with complex animations, but at least the Home Screen certainly seems to use exactly this kind of animated linear transformations:

Also, most Watch Faces are animated in a way, e.g. the moving seconds and minutes hands.

However, the WatchKit controls do not have a .transform property, and I could not find much in the documentation - the words "animation" and "graphics" are not even mentioned there.

So, the only way I currently see is to draw the vector graphics to a CGContext and then put the result as an UIImage to a image control, as described here. But this does not really seem energy-efficient. It is exactly the kind of "CPU pixel drawing" that we usually want to avoid if possible. I think it is not energy-efficient because if I draw on a 100x100 pixels image buffer, the image has to be scaled to the actual Watch screen size, so we have two actual drawing processes per frame.

Is there a officially recommended, energy-efficient way to do animations on the Apple Watch?

Or, in other words, can we animate things like they are animated on the Home Screen or Watch Faces?

I created a watch application and it works for me fine, while others pinpoint there is a crash being occurred. So since i cannot recreate, I found the crash logs from xcode for that build, and the crash logs looks like this,

I was building a standalone watch only application and I want to convert it to a dependant watch application since I need to use watch connectivity to exchange some data within the paired devices. So is it possible to directly convert this existing watch only application in the same project without creating a new target in my IOS project? Please if it is can anyone specify the instructions on how to do so?

And I also tried adding the companionbundleidentifier and it fails with the error