NullRef exception when referencing Fibonacci object

[Waxavi]

Hello NT8 Support,

I'm using an indicator which draws a Fib retracement, and I'm creating a strategy that uses this indicator, it seems under this setup, an error is generated when setting the Fibonacci extension to the right.

(Dummy example)

try
{
if (CurrentBar == 15)
{
var fib = Draw.FibonacciRetracements(this, "fib", true, 10, Low[10], 1, High[1]);
fib.IsExtendedLinesRight = true;
}


// Ensure enough bars exist for Value[1]
// if (CurrentBar == 0)
// {
// Value[0] = Input[0];
// }
// else
// {
// Value[0] = Input[0] * constant1 + constant2 * Value[1];
// }
}
catch (Exception e)
{
Print(e.Message);
Print(e.StackTrace);
throw;
}​

It says:
Object reference not set to an instance of an object.
at NinjaTrader.NinjaScript.Indicators.SmaFibonacci.On BarUpdate() in C:\Users\USUARIO\Documents\NinjaTrader 8\bin\Custom\Indicators\SmaFibonacci.cs:line 70
Indicator 'SmaFibonacci': Error on calling 'OnBarUpdate' method on bar 15: Object reference not set to an instance of an object.

Is it because these objects are drawn asynchronously when being referenced inside a strategy?

Is there a workaround for me to use this Fib retracement object?

Regards,

[NinjaTrader_Jesse]

Hello Waxavi,

Can you clarify, how is the strategy involved here? Is the strategy using the code shown or is that in the indicator? Does the indicator work when not used in the strategy?

[Waxavi]

Hello Jesse,

The strategy is only referencing the indicator, here-s the strategy code

public class SmaFibStrategy : Strategy
{
private SmaFibonacci _smaFib;

protected override void OnStateChange()
{
if (State == State.SetDefaults)
{
Description = @"Enter the description for your new custom Strategy here.";
Name = "SmaFibStrategy";
Calculate = Calculate.OnBarClose;
EntriesPerDirection = 1;
EntryHandling = EntryHandling.AllEntries;
IsExitOnSessionCloseStrategy = true;
ExitOnSessionCloseSeconds = 30;
IsFillLimitOnTouch = false;
MaximumBarsLookBack = MaximumBarsLookBack.TwoHundredFiftySix;
OrderFillResolution = OrderFillResolution.Standard;
Slippage = 0;
StartBehavior = StartBehavior.WaitUntilFlat;
TimeInForce = TimeInForce.Gtc;
TraceOrders = false;
RealtimeErrorHandling = RealtimeErrorHandling.StopCancelClose;
StopTargetHandling = StopTargetHandling.PerEntryExecution;
BarsRequiredToTrade = 20;
// Disable this property for performance gains in Strategy Analyzer optimizations
// See the Help Guide for additional information
IsInstantiatedOnEachOptimizationIteration = true;
}
else if (State == State.Configure)
{
}
else if (State == State.DataLoaded)
{
_smaFib = SmaFibonacci();
}
}

protected override void OnBarUpdate()
{
}
}​

And here's the indicator code:

public class SmaFibonacci : Indicator
{
protected override void OnStateChange()
{
if (State == State.SetDefaults)
{
Description = @"Enter the description for your new custom Indicator here.";
Name = "SmaFibonacci";
IsOverlay = true;
IsSuspendedWhileInactive = true;

AddPlot(Brushes.Blue, "TestSeries");
}
else if (State == State.Configure)
{
}
}

protected override void OnBarUpdate()
{
try
{
if (CurrentBar == 15)
{
var fib = Draw.FibonacciRetracements(this, "fib", true, 10, Low[10], 1, High[1]);
fib.IsExtendedLinesRight = true;
}
}
catch (Exception e)
{
Print(e.Message);
Print(e.StackTrace);
throw;
}
}
}​

Object reference not set to an instance of an object.
at NinjaTrader.NinjaScript.Indicators.SmaFibonacci.On BarUpdate() in C:\Users\USUARIO\Documents\NinjaTrader 8\bin\Custom\Indicators\SmaFibonacci.cs:line 67
Indicator 'SmaFibonacci': Error on calling 'OnBarUpdate' method on bar 15: Object reference not set to an instance of an object.

[NinjaTrader_Jesse]

Hello Waxavi,

When indicators are used from strategies they will not draw anything on the chart so drawing objects would not be used. You can just add a null check in the indicators code so that property is only set if the object actually exists.

if(fib != null)
{

}

[Waxavi]

Hello Jesse,

Understood, I was planning to retrieve data from this drawn object, so it seems I will have to decouple the drawn object from the data I need .

Thank you

Regards,