Strategy Properties persistence, attributes

[zweistein]

Hello,

actually while testing

http://www.ninjatrader-support2.com/vb/showthread.php?t=26571

I noticed a strange behaviour concerning the Properties of a strategy in a Disable/enable cylce of a strategy.

Lets assume I have a property

public string STRING1 {
...

}

when going through a Enable/Disable cycle, this should not change.

OK, above property will do so.

But if I apply the attribute

[Browsable(false)]
public string STRING1 {

}

then the property is not persistent and reset to zero each time the strategy is enabled.

Please explain the idea behind this (or is it a simple bug?)

Will the attribute [XmlIgnore] behave as expected?

Attached a sample strategy. Uncomment //[Browsabe ] to produce the - in my view wrong behaviour.

regards

andreas

[NinjaTrader_JoshP]

zweistein,

Let us take a step back. What are you trying to achieve? You cannot hide/ignore parameters like that. Those are for plots, not parameters.

[zweistein]

I am not trying to ignore a property.

I just need the value internally and there is no need for me to display them in the Properties. Therefore [Browsable(false)].
For the sake of get things working I just removed the [Browsable(false)] attribute and then the behaviour is as exected.

The example strategy given is clear. Please check and explain the -unexpected- behaviour.


regards
Andreas

P.S. I am working on a proper continuation of my strategies in an overnight scenario. Hence I save order.token strings in the strategy properties. These tokens are needed to find out what has happened with my position during the overnight period. (still in position or stopped out).

[NinjaTrader_JoshP]

I have forwarded your question to development for clarification.

[NinjaTrader_JoshP]

zweistein,

Development has taken a look and this will be the case when you use [Browsable(false)].

What we would like to determine is what are your requirements or use-case for something like a parameter that is not browsable? Why make it a parameter at all then? Thanks for the clarification info you can provide.

[zweistein]

Hello Josh,

>>What we would like to determine is what are your requirements or use->>case for something like a parameter that is not browsable? Why make it >>a parameter at all then? Thanks for the clarification info you can >>provide.

What I want is: In a Strategy I want to use properties and its relative attibutes the same way as used by MSDN and standard C#, for the attribute Browsable see the following link.

http://msdn.microsoft.com/en-us/library/system.componentmodel.browsableattribute.aspx

In my particular case I need to keep track of order tokens which I save as string properties of my strategy.

I do not understand you mentioning "parameter". What is a parameter for you?
A. Do you define a parameter as a Property with Attribute GridCategory("Parameters")?

B. Do you define Parameter any Property of a class derived from StrategyBase, even without the GridCategory("Parameters") Attrribute?


I am asking you because the "strange behaviour" describred is indipendent of the GridCategory of the Property. Even if I omitt GridCategory completely the behaviour remains "strange" and the Property is placed automatically in the "Misc" category.

What I wanted is just hiding the Property from visual display because I use it as an internal variable. By choosing it to be a property I would like to use the Serializable features that are automatically included with a variable beeing a public Property.
(see http://msdn.microsoft.com/en-us/libr...hh(VS.71).aspx ,
says )

regards

[NinjaTrader_Dierk]

There may be some confusion:

- 6.5: strategy parameters are tagged with Category("Parameters"). Anything else may or may not have worked. You should NOT tag such parameter with Browsable(false).

- 7: strategy parameters now are tagged with GridCategory("whatEverNameYouLiked") to provide you more flexibility. You should NOT tag such parameter with Browsable(false), same as 6.5, nothing has changed.
Any other "non-parameter" property you could tag (if needed) with Category("whatEverNameYouLiked"). DON'T use GridCategory for those.

[zweistein]

Hello Dierk,

thanks for enlighting.
As I understand you are saying that as long as a property does not have a GridCategory("Parameters") attribute it it not considered a strategy parameter. Hence in such a case Browsable(false) can be used and will work as per MSDN C# documentation.
Correct?


My findings with MyCustomStrategy are however different:

just modify the property attributes to (comment out GridCategory)

//[Description("")]
//[GridCategory("Parameters")]
[Browsable(false)]
publicstring STRING1
...



and you will see that also this -non Parameter - property will be reset to "" each time you go through a Enable/Disable cycle of the strategy.
I would say this is a bug.

Thank you for enlighting further

Andreas



P.S. In my view the problem arises from a particular NinjaTrader behaviour: All Properties of a strategy get ALWAYS tagged by NinjaTrader: If no tag is found then the "Misc" tag is automatically applied. This is done internally by NinjaTrader.
So my question: How to disable automatic tagging of strategy properties by NinjaTrader?

[NinjaTrader_Dierk]

As you enable a strategy a new instance is created and started. The new instance is created as a clone. Only those properties which are Browsable(true) will be cloned. Same applies to indicators. This is "since day 1" logic which I'd rather not touch to not break stuff.

[NinjaTrader_Dierk]

Thinking about a resolution to that issue... you could overwrite the Clone() method, call base.Clone() first and then clone your Browsable(false) properties.

[zweistein]

Thanks Dierk,

I tried it and your suggestion works, excellent!

regards

[NinjaTrader_Dierk]

Great, thanks for your feedback.