How to save data before potential crash

I am working on an app that will intentionally get into situations where it will crash. My intention is to save the status before calling the code that might crash, and then when the app is started again it'll be able to display data that was saved.

Currently I'm trying to save 2 numbers and a boolean:

function foo() as Void {
    setConfig("sport", self.sport);
    setConfig("subSport", self.subSport);
    setConfig("crashed", true);
    session = ActivityRecording.createSession({
        :name => "" + self.sport + ":" + self.subSport,
        :sport => self.sport as Activity.Sport,
        :subSport => self.subSport as Activity.SubSport,
    });
    session.start();
    session.stop();
    setConfig("crashed", false);
}

My problem is that the config is only written to the properties if I exit with System.exit() but not when (well my intention: before) there's a crash. Also the errors that cause the crash are not catchable exceptions :(

Any idea how can I make this work?

(:no_properties, :no_ciq_2_4_0, :inline) // NOTE: forbidden to set properties in background
function setConfig(key as PropertyKeyType, val as PropertyValueType) as Void {
    Application.getApp().setProperty(key, val);
}
(:properties, :ciq_2_4_0, :inline) // NOTE: forbidden to set properties in background
function setConfig(key as PropertyKeyType, val as PropertyValueType) as Void {
    Properties.setValue(key, val);
}

0 FlowState 16 days ago in reply to FlowState

To be even clearer, the whole point of suggesting saveProperties() on CIQ < 2.4.0 is that obviously Storage is unavailable on CIQ < 2.4.0, so you have no other conceivable way of persisting information immediately, unless you want to do something crazy like abuse PersistedLocations to save unrelated data.

EDIT: persistedlocations really won't work since the app can't read them back unless it's running on a CIQ 3 device

0 FlowState 16 days ago in reply to FlowState

Well, there is another way of persisting information immediately.

You could use record a FIT session with custom FIT fields that have the information you want to persist. Obviously you would have to make sure that FIT session doesn't crash.

However, on older devices there was once a bug where creating a FIT session too quickly after saving the last one would cause the device to go nuts (it would freeze and vibrate endlessly), so I would be careful about that one.

Obviously this wouldn't help if the app needs to read the information on next run.

0 jim_m_58 16 days ago in reply to flocsy🤠

No. In fact with saveProperty, if you didn't have a property for the key, it was saved in the object store (.str file) and not settings.(.set file)

The max size of either is about 8k, while with Application.Storage, each key can be about 8k. Application.Property uses a .set file which may be the same as the old one. I never checked and moved to Application.Storage and Application.Propery when they were first available. I use a "has" checkwhere I still use the old stuff on old devices.

0 FlowState 16 days ago in reply to FlowState

To be absolutely clear, you have nothing to lose by using saveProperties on a device with CIQ < 2.4.0.

At best, it fulfills your use case.

At worst, it doesn't do anything and you're no worse off than before.

0 flocsy🤠 16 days ago in reply to FlowState

I see you recommend saving data to FIT in multiple threrads. In fact if you look at my code in github I already do that.
However it doesn't solve the problem we're talking about here, because it's a "write-only" thing. CIQ app can only write it and no way to read it back. That not useful for anything I'm trying to do here, but especially not for the crash case, when the fit file won't be written at all (most probably).

0 flocsy🤠 16 days ago in reply to FlowState

I added this (still not pushed) but in the simulator it doesn't change a thing.

if (AppBase has :saveProperties) {

AppBase.saveProperties();

}

0 FlowState 16 days ago in reply to flocsy🤠

flocsy🤠 said:
That not useful for anything I'm trying to do here, but especially not for the crash case, when the fit file won't be written at all (most probably).

You don't think it'll be written at the moment you save the session, as opposed to later on?

If the FIT file is saved later on (e.g. when the app exits), how do you think:

- it's possible for an app to create a 2nd session after saving the 1st one, without restarting the app? recording fit files takes significant memory, and the memory usage doesn't increase accordingly when you create a 2nd session (as if 2 sessions were in memory at the same time)

- it was possible for a device to crash when a 2nd session is started too soon after calling save on the first one

- it's observed that when a device app saves a fit session, the device freezes (you can see this on older devices, especially)

it's a moot point because it doesn't fit your use case.

sorry i mentioned it

0 jim_m_58 16 days ago in reply to flocsy🤠

That call have been a no op since the early days of CIQ. Calling it does nothing.

0 FlowState 16 days ago in reply to jim_m_58

Fair enough, too bad

0 flocsy🤠 16 days ago in reply to FlowState

My app (again look at github) actually creates hundreds of sessions. If you start it it'll create from sport:0, subSport:0 to sport:86, subSport:124

But it doesn't change the fact that it can only be read outside the CIQ