Close[i], Open[i]... outside OnBarUpdate() ???

[ninZa]

Hi,

I test this code:

        int i = 0; // we will change the value of i to 1, 2, 3 ....
	if (Close[i] > Open[i]) Print("Bull");
	else if (Close[i] < Open[i]) Print("Bear");

Put the code in OnBarUpdate: OK it works.

However, a problem occurs when I put the code in my button click event:

void ToggleClick(object sender, RoutedEventArgs e) {
...
}

For i = 0: it works
For i = 1, 2, 3...: the following error happens, even though we already have hundreds of bars on chart

Unhandled exception: Object reference not set to an instance of an object.

This means we cannot access the historical values of Close, Open, Low, High series outside OnBarUpdate ??? This will be a really serious problem!!!

Thanks.

[NinjaTrader_Jesse]

Hello,

The basic series such as Close[0] can be used throughout the script so long as there is data for the index location being accessed, for example you can use it in OnMarketData.

Can you post a sample that demonstrates the error? That would better help identify what may be happening, otherwise based on the error you may need to check what is null to see where the error is coming from.

Please let me know if I may be of further assistance.

[koganam]

Hi,

I test this code:

        int i = 0; // we will change the value of i to 1, 2, 3 ....
	if (Close[i] > Open[i]) Print("Bull");
	else if (Close[i] < Open[i]) Print("Bear");

Put the code in OnBarUpdate: OK it works.

However, a problem occurs when I put the code in my button click event:

void ToggleClick(object sender, RoutedEventArgs e) {
...
}

For i = 0: it works
For i = 1, 2, 3...: the following error happens, even though we already have hundreds of bars on chart


This means we cannot access the historical values of Close, Open, Low, High series outside OnBarUpdate ??? This will be a really serious problem!!!

Thanks.

Have you escaped the initial bars correctly?

[NinjaTrader_Matthew]

Hi,

I test this code:

        int i = 0; // we will change the value of i to 1, 2, 3 ....
	if (Close[i] > Open[i]) Print("Bull");
	else if (Close[i] < Open[i]) Print("Bear");

Put the code in OnBarUpdate: OK it works.

However, a problem occurs when I put the code in my button click event:

void ToggleClick(object sender, RoutedEventArgs e) {
...
}

For i = 0: it works
For i = 1, 2, 3...: the following error happens, even though we already have hundreds of bars on chart


This means we cannot access the historical values of Close, Open, Low, High series outside OnBarUpdate ??? This will be a really serious problem!!!

Thanks.

I'm not able to reproduce the object reference error, could you provide more details on how to trigger that? Do you know which object is null in your debugging?

In my testing though, I do see where accessing the price series object outside of the internal handlers like OnBarUpdate do result in the Open[0] providing the first bar on the chart. So if you accessed Open[1], it would be expected to get an index out of range exception.

In principle, you should not be accessing these series values outside of the internal handlers by an index.

So I can help provide a solution or at the very least, provide an enhancement request, can you please outline your full usecase for this? Please elaborate on what you intend to do with this data from the click handler and I can see if there is a documented way to achieve that, or we can review your use case and see if there is something we can do in the future to handle as well.

[jeronymite]

Close[i], Open[i]... outside OnBarUpdate() ???

Matthew wrote:

In principle, you should not be accessing these series values outside of the internal handlers by an index.

Could you clarify, please? Why would these data not be available in all methods, provided the State was valid for accessing them?

I'm sure that many traders, like myself, have some complex code that requires these data series outside of any pre-defined methods in NinjaScript. Am I missing something obvious?

Thanks.

[NinjaTrader_Matthew]

Matthew wrote: Could you clarify, please? Why would these data not be available in all methods, provided the State was valid for accessing them?

I'm sure that many traders, like myself, have some complex code that requires these data series outside of any pre-defined methods in NinjaScript. Am I missing something obvious?

Thanks.

There are pointers in these methods to ensure the current bar is up to date, and accessing these PriceSeries outside without that code is unpredictable.

If you need to access values outside, you can use an absolute index which would get you the the value.

Open.GetValueAt(CurrentBar - barsAgo);

or

Open.GetValueAt(ChartBars.Count - barsAgo));

or

Bars.GetOpen(CurrentBar - barsAgo);

If there is some reason you would need the PriceSeries array, because you cannot fetch these values using the absolute index, we would be interested in the use case, as there are other documented ways to get these values.

[ninZa]

I found out the reason: bypassing TriggerCustomEvent causes the issue.
Here it is:

INCORRECT

void ToggleClick(object sender, RoutedEventArgs e) {
	if (Close[Index] > Open[Index]) Print(Index + ": Bull");
	else if (Close[Index] < Open[Index]) Print(Index + ": Bear");
}

CORRECT

void ToggleClick(object sender, RoutedEventArgs e) {
	[B]TriggerCustomEvent[/B](o => {
		if (Close[Index] > Open[Index]) Print(Index + ": Bull");
		else if (Close[Index] < Open[Index]) Print(Index + ": Bear");
	}, e);
}

I don't bypass TriggerCustomEvent in a serious programming, but previously I just quickly tested out my idea so I forgot it (or lazy). This proves the power of TriggerCustomEvent in guaranteeing a stable operation for indicators.