Is it possible to pass a double variable as an argument in Timer Trigger Azure function?

Question

I am making a Timer trigger Azure Function. I am using a variable here which indicates TimeToCopy. This variable has to be updated after every iteration of the function.

I have:

[FunctionName("Function1")]
    public static void Run([TimerTrigger("0 */2 * * * *")]TimerInfo myTimer, TraceWriter log, myTimerItem elapsedTime)

I want to:

[FunctionName("Function1")]
        public static void Run([TimerTrigger("0 */2 * * * *")]TimerInfo myTimer, TraceWriter log, myTimerItem elapsedTime, double TimeToCopy)

Answer 1

Functions can't reliably keep the state between the calls in memory.

If you can accept the possibility of data loss, you could maintain the value in a static variable.

To save/restore the state reliably you need to add additional binding to your function, e.g. to utilize Table Storage. Something like:

[FunctionName("Function1")]
public static void Run([TimerTrigger("0 */2 * * * *")] TimerInfo myTimer, 
                       myTimerItem elapsedTime,
                       [Table("MyFuncState", "default", "Function1")>] StateEntity entity)
{
    // ...
    entity.TimeToCopy = entity.TimeToCopy * 2.0;
}

public class StateEntity: TableEntity
{
    public double TimeToCopy { get; set; }
}