iOS: Simulating user quitting app - ios

I just added persistent data into my app and wanted to test it with my iPhone. When I quit my app (double tap home and swipe up), I'm unable to open it again (the icon freezes). When I try the same thing on the iOS simulator in Xcode, it crashes too. I get a SIGTERM error coming from my AppDelegate. Is this what is supposed to happen when the user quits while testing, or is this an issue with my data? Is there any way to simulate the user quitting and restarting the app to make sure my data is still there?
Thanks

This is not what is supposed to happen when the user quits while the Xcode debugger is attached (at least not anymore — this question is a couple years old after all).
If you force quit an app while running from Xcode (whether simulator or on a physical device) it just stops the debugger and you should be able to relaunch it without issue. The Xcode debugger will not be attached when you launch like that, but from Xcode you can attach the debugger to an existing process (Debug > Attach to Process).
Note, if run in Xcode and then you quit the simulator application on your Mac (or close the simulator's window) then you will get a SIGTERM error in main.swift. But this is not the same as a user terminating your app, nor is it comparable to a user turning off their device.
From what you're describing it sounds like there is a bug in your code that is causing it to freeze when launching when the debugger is detached or when it's relaunching after termination.
To simulate the user quitting and restarting you should be able to terminate the app from your device/simulator, and then either run it again from Xcode or launch it from the device/simulator and attach to the process from Xcode.
In some cases it may be helpful to put in some debugging code that pops up an alert / update some label at runtime to indicate the data persisted properly after the app re-launched so that you don't always have to have Xcode attached to diagnose problems in your app.

This is the correct behavior if you are running the app from Xcode. However, once you've uploaded/run the app once, you can test closing and reopening it. Simply stop the run in Xcode, go to your phone or simulator, and click on the app icon to open it. Unfortunately, you won't have a debugger log at that point, but you can see if your data persists.

Related

Cannot run iOS Keyboard Extension on device

Previously I've been able to run and debug a custom keyboard extension on my personal device by selecting the appropriate scheme, selecting the Messages app (MobileSMS.app) executable to run in, and then opening a conversation.
However lately whenever I attempt to run the Messages app, Xcode will automatically terminate with the message Finished running MobileSMS.app on iPhone. The app will launch on my device, but the session is completed and therefore I'm unable to debug the keyboard app.
It still works fine on the Simulator.
Does anyone have any experience with the same issue? Any ideas how I can go about troubleshooting it?

Swift application quits after open, works from Xcode

I am encountering a strange situation with a simple application I develop. When I deploy the application using Xcode (with debugger attached), it works perfectly.
When I close Xcode, disconnect the phone, kill and restart the application, it works just fine, too! For several hours that is.
After some time (usually the next day morning) when I try to open the app up, it immediately fails. A white rectangle filling the screen animation does happen, but when the application is supposed to flash its UI in, it quits instead.
How can I get ahold of the crash logs from the iPhone? Does it store any? This application is not from the AppStore, it's my development application installed through Xcode.
When I re-deploy it after finding this has happened again, hoping I'll get something with a debugger attached, it starts working again. This has happened to two of my apps.
You could try to look into your device's logs: Window->Devices -> Select your device-> Click 'View Device Logs'. Find your app crash there and on the right side you should see a crash report.

My WatchOS2 app stuck on launch with Spinner

I built a demo app on WatchOS 2.0.1, on every launch it was getting stuck with App name on Top Left corner and spinner in middle of screen on iWatch (38mm). Watch is brand new and have only native apps installed till now so there should not be any issue with memory.
I tried many times to open the app but it was repeatedly closing automatically after showing Spinner for sometime. After lots of trial my Apps screen got visible and then after on every launch it worked fine without sticking on launch. I tried to double check by Force quit my app using Power button but it worked fine then after.
Then I uninstalled the app from watch and reinstalled it and same thing happened again. It started sticking. Do anyone have Idea on this? Please help on this part.
WatchOS Version : 2.0.1
Your app is crashing, as evidenced by it "automatically closing."
You should be able to track down the reason for the crash by examining the crash report (which can be found in the Xcode Window -> Devices pane). Alternately, you should be able to interactively debug this by running the app within Xcode.
As for it eventually no longer crashing until you deleted and reinstalled the app, the app reached a state where the reason for the crash no longer occurred. This probably is related to needing to handle some error pertaining to a path or file which it is finally able to create or access. Deleting the app recreated the condition where it repeatedly crashed again.

Debug WatchKit on real Apple Watch - Nothing happens

I am struggling with debugging my WatchKit Extension/App on a real Apple Watch. Debugging both the iPhone App and the WatchKit Extension using the simulator the simulator is not problem:
Select the WatchKit App Profile and run in Simulator ==> App is launched on in Watch Simulator and I can use breakpoints in the Extension code to debug.
To debug the iPhone app as well I launch the app in the simulator and attach the debugger manually ==> I can use breakpoints in the iPhone Code to debug.
It is no problem to observe both the work of the iPhone app and the watch app. At least not in the simulator.
I would like to do the same thing on a real Apple Watch. But when I select the WatchKit App Profile and my real iPhone (instead of the Simulator) and click on "Run" nothing happens. This means Xcode seems to build and start the app but nothing happens on the devices. The status field in Xcode shows:
Building MyApp WatchKit App: MyApp WatchKit Extension
Building MyApp WatchKit App: Finishing...
Running MyApp on My iPhone 6
This is all. No debug Window, breakpoints are ignored or do not work and the app is not launched neither on the iPhone or on the Apple Watch.
I found other questions about problems with debugging on real devices (e.g. here) but they all deal with installation and signing issues. In my case both the iPhone App and the WatchKit App are installed without any problem. When I click the app icon on the Watch I can start and use the app. Problem is that I cannot debug this process.
Why do I need to debug the process on real devices? Well there is one thing I cannot test using the simulator: What happens when the Watch App tries to contact the iPhone app using openParentApplication:reply: when the iPhone app is not already running? This works perfectly in the simulator but on real devices the Watch Apps seems to get no reply from the iPhone app and simply waits forever.
I already found hints to solve this but without being able to debug the Watch App and to see how the code is executed I cannot be sure what is going on...
thank you for your answers. I finally managed to get the debugging running (most of the time) on my real Apple Watch. However it is quite cumbersome and not very reliable. There is not enough space in the comments so I will use this answer to describe my solution. Maybe it is help full to other:
Make sure, the App on your Watch is not running (as BalestraPatrick described). Launch the app and hold the side button a few seconds to bring up the "Turn off your Watch" dialog. Hold the side button for another few seconds to close the app and to return to the Watch homescreen.
Make sure the iPhone is not locked.
Select the WatchKit App target and your real iPhone and run the project.
Running the Watch App resulted quite often in an error SPErrorInvalidBundleNoGizmoBinaryMessage. Re-starting Xcode and cleaning both the Watch App and the App target solved this.
If the build of the Watch App succeed there will be a short message in Xcode but nothing on your iPhone or Watch. If you have made changes to the Watch App it will take a few seconds to refresh the app on the Watch. This is indicated by the progress-circle overlay over the app icon. If you made no changes ore once the app has been transfered: Launch the watch app manually by tapping the icon. There will be no automatic launch.
In most cases Xcode will recognize the app launch and attach its debugger to it. This will allow to use breakpoints, inspect the code, etc.
In my case I whanted to inspect how the iPhone App handles the application:handleWatchKitExtensionRequest:reply: call when the app was not active before. This is important because this cannot be done using the simulator. If the app takes to long to handle the request the Watch will receive no valid response.
After following the steps described above Xcode is only attached the watch app and will not hold on breakpoints in the iPhone app code. To do this, one has to manually attach the Debugger to the iPhone app process that is started when the watch app sends its call.
To be able to attach the debugger I added a delay to the apps main function: [NSThread sleepForTimeInterval:5]:
Select function in Watch App that will start the call to the iPhone App
The iPhone App will be launched in background. The delays gives you 5 seconds to attach the debugger.
Choose Debug\Attach To Process\Likely Targes\Your iPhone Appin Xcode to attach the debugger.
After the 5 seconds delay the process will continue and you will be able to use breakpoints in your iPhone app code as well.
Do not forget do remove the delay code when you finished testing :-)
NOTE:
You will not be able to see NSLog output (or any console output at all) from the iPhone App since attaching the debugger does NOT re-route the console output.
Happy testing with this awesome new Apple product :-P
I am having the same kind of issue but to improve a little bit the debugging experience I usually restart my devices a few times. Try to restart your Apple Watch or your iPhone.
Before launching your app from Xcode, make sure that the app is completely closed on your Apple Watch (not stuck in the loading screen for example). To do that, you have to force close the app: enter your app, keep the side button pressed until the menu to turn off the watch appears, then press the same side button for a few more seconds until the watch will go back to the homescreen and force close your app.
Now you can try to build and run the app from Xcode and it should work more reliably.
watchOS 3+:
The force quit is done by pressing and holding the side button (the button just below the Digital Crown) until the shutdown screen appears, and then
let go of the side button, then press and hold the Digital Crown.
Here's a technique that seems to be be the most reliable for me, even though it still only works about 25% of the time (Xcode 7 beta 4, 7A165t):
Run the phone target in debug (on your actual iPhone of course)
While the iPhone app is still running, switch to the watch target and run that in debug.
Keep an eye on your watch homescreen as the app installs. Once the app has installed, tap it to open it. This will sometimes "kickstart" the watch app and allow the debugger to catch it. At this point you should be able to debug both your iPhone app and watchOS app together.
This question has different answers. All are good.
The reason is: in my experience there are at least two different problems that prevent debugging on a real watch. Both require a different strategy.
This answer tries to help you to decide when to use which strategy.
XCode installs, tells you it is running for a short time and then stops showing "running...".
start with the answer of BalestraPatrick:
restart your devices.
Do not forget to restart your iPhone. This did the trick the first time I had this problem.
XCode installs, tells you it is running for a longer period of time: "running <projectName> on Apple Watch of <yourname>.
start with the answer of Jay Hickey or Andrei Herford
starting the watch app manually probably does the trick.
I also had times when XCode was able to start my watch app without any help from me.
Bonus:
Starting with XCode 7.1 it seems XCode doesn't always compile all necessary Swift files (more often than before). This is not watch specific, it also applies to iOS apps. The symptoms can look similar to those of this question. -> clean your project and then restart XCode.

iOS: How to debug "freshly launching" an app from a URL

When launching an app from a URL, there is a distinction between whether the URL is freshly launching an app, or if it's resuming an app that has been put into a suspended state.
My question is, how do I debug the process of a "fresh launch" from a URL? Hitting "Run" in Xcode automatically opens the app. Then, I have to suspend the app to reach Safari and access my test site. But if I close my suspended app, Xcode is no longer attached to it and I'm unable to debug.
These steps can be followed on the device. Founded at this link.
Run the app from Xcode to install it on your device and then stop it
from Xcode.
Force quit the app from the app switcher UI on the device.
Navigate to the scheme for the project in Xcode. Under the Run
section's Info tab, there is a radio button for "Wait for executable
to be launched". Make sure this is checked instead of the
"Automatically" option.
Run the app from Xcode. It will not open
on the device, but the debugger will wait for it to open and then it
will attach to it.
On the simulator as suggested by Marc-Alexandre Bérubé.
Run your app on the simulator.
Force quit the app on the simulator. Press cmd+shift+(hit h twice). Swipe the app up.
Open your terminal and enter this xcrun simctl openurl booted http://yourdomain/path.
You need to configure your Xcode app scheme to wait for the app to be launched manually.
Here is how you do it: http://blogmobile.itude.com/2013/09/03/how-to-debug-deep-linking-in-ios/.
You then need to copy the launch URL and paste it to Mobile Safari. This will launch your app, and make Xcode get attached to the running app process.
While the answers that mention activating "Wait for executable to be launched" are good in theory, for various reasons these didn't work for me. On the simulator, though Xcode claimed it had "attached", no logs or breakpoints were ever shown. On-device I was running iOS 13, building from Xcode 10, and using Xcode 11 to load, so I didn't have any debugging symbols. That was more of a personal problem, I suspect on device debugging may have worked.
What worked best for me was just opening up Console.app on my mac, and using the OSLog APIs to get a solid stream of caveman debugging from the simulator.
Run the app from Xcode on the simulator.
Then immediately quit it on the simulator via the app launched (Cmd-Shift-H * 2)
Launch the app by tapping a deep link I sent to myself via the Messages app
Observe my logs in Console.app
It's not pretty, but it is highly reliable.
It's also worth mentioning, that you can protect this useful feature by testing cold start deep-linking via XCUITest. You can call app.terminate in your XCUITests, then open a deep link (typically via a static web page you've setup, I use public GitHub wikis for this) and write tests and assert behaviors just like normal.

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