Calling App Designer object methods from within Timer Callback

Within my app in App Designer I have an object X with its own class methods. I am trying to call this method on a schedule using a timer object within the app. However, whenever I try to do this I get an error from the timer callback function library. It seems that the method call might be being interpreted as another timer callback function though I'm not sure? I have other timer functions that just set application properties (app.Y = 'on') without issue.

What could be the cause here?

The callback function is set here:

app.pageTimer.TimerFcn = @app.timer_event;

and defined here:

function timer_event(app, obj, event)
  if app.property
     app.X = app.X.method() % call the method on app object
  end
end

//EDIT for Error Message. - Throw by timercb.m

Error while evaluating TimerFcn for timer 'timer-19' 
Brace indexing is not supported for variables of this type

[Adam]

Please give full error messages if you get an error, it is a lot easier than you interpreting the error and passing that on, which may or may not be a correct interpretation of it.

[Kevin Chng]

I did't see any error.

where do you put your function timer_event(app, obj, event)?

Answer 1

[Mike Scott]

Found the answer thanks Adam and Kevin.

The problem was arising in part of the called function. I am a newbie to MATLAB, it looks as though the error handling is different when executing as part of a timer callback.

Instead of performing a trace to flag the offending function it looks like MATLAB routes any error through the timer callback handling, hence my confusion.

thanks