How to correctly initialize a fit contributor object from a simpledatafield?

I have a simpledatafield which provides a value. I want this value to be logged if the simpledatafield is used during an activity with logging.

I found the Fitcontributor example in the SDK's samples and understand that i need to create a Field object.

Below is my code. It compiles, but crashes during runtime with error

Error: System Error Details: Failed invoking <symbol>

regarding line 14.

What's wrong here?

import Toybox.FitContributor;

class ForumsladerView extends WatchUi.SimpleDataField {

        private var _fitRecording as FitContributor.Field; // fit recording contributor

        ...

        public function initialize(dataManager as DataManager) {

        ...

        // Create the custom FIT data field we want to record
        _fitRecording = createField(
            "Forumslader", 0, FitContributor.DATA_TYPE_FLOAT,
            {:mesgType=>FitContributor.MESG_TYPE_RECORD, :units=>"FL"}
        ) as FitContributor.Field;

        _fitRecording.setData(0.0);

    }

0 FlowState over 2 years ago

I played with this briefly, and I was able to reproduce the crash by placing the call to createField() in compute(), in the MoxyField example (which is a DataField, rather than a SimpleDataField.) In that case, it crashed on the very first call to compute().

For some reason, the crash doesn't happen when I do the same in the SimpleDataField example.

Not sure what's happening in your case.

0 CYBERMAN54 over 2 years ago in reply to FlowState

Thanks for your answer and hints. I did some more testing, tried several moves, but no success yet. It looks exactly like the issue someone posted for Fenix 7. Thus, i will continue that thread.

0 flocsy🤠 over 2 years ago

try what happens when you call SimpleDataField.createField or even DataField.createField

0 CYBERMAN54 over 2 years ago in reply to flocsy🤠

Same issue with both.

0 CYBERMAN54 over 2 years ago in reply to CYBERMAN54

Now i split line 14 in two lines:

_fitRecording =

createField(

The error is still thrown for the first line. Maybe it's not createField which causes the missing symbol?

0 flocsy🤠 over 2 years ago in reply to CYBERMAN54

I also thought about that, and almost wrote to create a variable with all the parameters to createField on a separate line. But then the error message "Failed invoking <symbol>" would not make sense, would it?

0 FlowState over 2 years ago in reply to CYBERMAN54

CYBERMAN54 said:
Now i split line 14 in two lines:

_fitRecording =

createField(

The error is still thrown for the first line. Maybe it's not createField which causes the missing symbol?

I don't think that's it. I think the error message just refers to the first line of the statement which crashed.

Consider this code which causes an array out of bounds runtime error.

var foo = [];
var bar;
bar = // stack trace points to this line
   1 +
   2 +
   foo[-1] + // actual error is here
   4;

Seems like a limitation of the compiler to me.