Serialization error

[photog53]

FYI

I just got a weird error when closing my workspace.
(see attached .png)

I was using the standard Ninja 'Volume UpdDown" indicator on a chart.
Everything worked fine all afternoon....until I closed the workspace, at which point I got this error message...

"Indicator 'NinjaTrader.Indicator.VolumeUpDown' could not be serialized.
Please refer help for more information on serializing indicators."

Not at all sure why NT7 didn't like it's own indicator...

Not a serious problem for me....but thought you might like to know.

[NinjaTrader_JoshP]

Does your indicator use custom colors? You would need to serialize those parameters.

http://www.ninjatrader.com/support/forum/showthread.php?t=4977

[photog53]

Nope.....I loaded the indicator straight from NT7.....just like it came.
(I didn't modify color, bar size, or panel....let it run 'stock')


Also....in case I wasn't clear before, this is not one of my indicators....


// Copyright (C) 2007, NinjaTrader LLC <www.ninjatrader.com>.
// NinjaTrader reserves the right to modify or overwrite this NinjaScript component with each release.


This is the 'standard version' that came with NT7.

[NinjaTrader_JoshP]

Can you please provide the workspace you are using along with the NT7 version you are using? Thank you.

[Harry]

XmlIgnore() in Bollinger Indicator

If code an indicator which calls the Bollinger average via

 
int numStdDev = 2;
int period = 14;
double average = Bollinger(numStdDev, period).Upper[0];

and then want to export it, I get an error message. The problem is the code line

 
[XmlIgnore()]

that preceeds the DataSeries of the Bollinger indicators in the Properties region. If I delete these lines from the Bollinger indicator it works.

What is the benefit of setting [XmlIgnore()] ?

[NinjaTrader_JoshP]

[XmlIgnore()] is a C# concept. Please see here for more information: http://msdn.microsoft.com/en-us/libr...xmlignore.aspx

[Harry]

My question was, why you put it in the NT Bollinger indicator code?

Because of this the NT Bollinger indicator cannot be correctly called by other indicators!

[NinjaTrader_JoshP]

Let us take a step back. What exactly are you trying? What do you mean by "export it" and what error message are you referring to? Thanks.

[Harry]

(1) If I call Bollinger within another indicator (for example Bollinger(1,period).Midline[0]) that works fine.

(2) If I want to export the new indicator via NT -> error message, could not be exported, please check your logs. The logs are empty.

The reason for the error message is that XmlIgnore() command in the Bollinger Indicator! That command prevents any indicator which is calling Bollinger from being exported properly.

So I modified the Bollinger indicator by deleting the offensive code, and now any indicator calling it, could happily be exported.

Let us take a step back. What exactly are you trying? What do you mean by "export it" and what error message are you referring to? Thanks.

[Harry]

NT 7.0.0.20

Here is a specific example.

The indicator example 1 calls BollingerIND (which is the Bollinger indicator with the XmlIgnore() commands removed). It can be easily exported.

The indicator example 2 is identical with example 1, but calls Bollinger instead of BollignerIND. It cannot be exported, but the error message below is shown. The error code is CS0103: "The name "Bollinger" does not exist in the current context (see HelpguideV6 ??? for export problems).

This problem is created by the XmlIgnore() code in the Bollinger indicator, as the DataSeries cannot be exposed correctly with this code. So you should remove that offending code.

Attachments Example 1 (exported) and Example 2 (cs file that cannot be exported by NinjaTrader)

[NinjaTrader_JoshP]

Harry,

Please see the link provided in the log message. It outlines steps you should do when such a scenario is hit.

Expand the .NET Referencing section here: http://www.ninjatrader.com/support/h...ort%2Bproblems
You should not be removing XmlIgnore(), but instead should simply include the System Indicator into your export.

[KBJ]

What is the benefit of setting [XmlIgnore()] ?

The benefit to using [XmlIgnore()] before a property is that it prevents that property from being serialized, which means that the property's value is not saved when you save a chart template or a workspace.

Thus [XmlIgnore()] is used before DataSeries properties since a DataSeries never gets saved in a template/workspace. It is also used for Color and Pen properties, etc. since these require special handlings (converting color names and pen attributes to strings or numbers) to serialize the files for templates & workspaces -- the code for serializing colors is all over the place in various indicators and for pen serialization, see http://www.ninjatrader.com/support/f...ad.php?t=22724.

[Harry]

The benefit to using [XmlIgnore()] before a property is that it prevents that property from being serialized, which means that the property's value is not saved when you save a chart template or a workspace.

Thus [XmlIgnore()] is used before DataSeries properties since a DataSeries never gets saved in a template/workspace. It is also used for Color and Pen properties, etc. since these require special handlings (converting color names and pen attributes to strings or numbers) to serialize the files for templates & workspaces -- the code for serializing colors is all over the place in various indicators and for pen serialization, see http://www.ninjatrader.com/support/f...ad.php?t=22724.

Thanks for the comment. I have serialized all sorts of colours, dates, time spans and sometimes I have forgotten to remove the [XmlIgnore()] which has caused problems, as the serialized values were not saved as part of the workspace. I understand that you want to save some of the parameters such as a period of a moving average with the workspace, and that obviously you do not want to save the values of a dataseries, which is based on price.

If I want to export an indicator using the SMA , SMA is automatically included with the exported file. The [XmlIgnore()] prevents NinjaTrader from including the called system indicator with an exported file. So you have to include it manually. Strange.

[NinjaTrader_JoshP]

Harry,

Basically this is what is happening.

On certain PC setups for various reasons related to the combination regional settings of the computer and the settings of the .NET install the .NET referencing simply does not work to pick up some of the system indicators. When such a scenario occurs the way around this is to manually add the system indicator. The help guide instructions were written specifically for the scenario you are running into and in fact is the exact reason we added the ability to manually add system indicators in the export which was not possible in 6.5.

[Harry]

Thanks Josh.

confirm it works, when manually adding the references.

Was just astonished that the XmlIgnore() was the reason that references were not being picked up automatically.

Harry,

Basically this is what is happening.

On certain PC setups for various reasons related to the combination regional settings of the computer and the settings of the .NET install the .NET referencing simply does not work to pick up some of the system indicators. When such a scenario occurs the way around this is to manually add the system indicator. The help guide instructions were written specifically for the scenario you are running into and in fact is the exact reason we added the ability to manually add system indicators in the export which was not possible in 6.5.