Modify input when starting an indicator

[cre8able]

I have an input to an indicator, lets call it Length, that I'd like to modify depending on what the chart period is.

But I'd also like to allow the user to set it manually if they don't want to use the default. So if they enter 0 in the Length input, it will auto calc. If they put 500, it will make Length 500.

I can do the check in OnBarUpdate, but only need to do it if they change it so that seems like a lot of unnecessary work.

Where can I put something like this so that it will only calculate once, but wont change the user input?

if ( Length == 0)   Length = 1000 / BarsPeriod.Value;​

I've tried a couple places in OnStateChange, but can't seem to get it to work

thanks

[NinjaTrader_ChelseaB]

Hello cre8able,

Use a private variable to store the calculated value.

Check and assign the value in OnStateChange() when State is State.DataLoaded.

private double useLength;

In OnStateChange():

else if (State == State.DataLoaded)
{
useLength = Length == 0 ? 1000 / BarsPeriod.Value : Length;
}

In OnBarUpdate():

Print(useLength);