Creating a Reusable Class

[Yandychang]

I created an abstract CustomIndicatorBase class, in order to reuse my Code... I did it in NT 7 for my startegies and it worked well. But when I try to create them for NT 8 as an Indicator, the ninjatrader Generated Code returns a problem. When it tries to create a new Instance of the Indicator( since Abstract Classes cannot be instantiated) I get a cannot create an instance error:

. How can I tell NT not try to create an instance of this indicator class and still be able to use it and create future indicators?

[NinjaTrader_PatrickH]

Hello Yandychang,

Thank you for your post.

Can you provide an example of the code that generates an error?

[Yandychang]

Abstract Class

Sure, Attached is a test code that reproduces the error, could not make it into a Zip because NT 8 says I have to fix the error before exporting...

[NinjaTrader_Jesse]

Hello,

Thank you for providing the sample,

I tried this concept in NT7 but do also see the same error that the abstract class can not be created. Additionally I see that you said in NT7 you used this for Strategies and now are using it for Indicators, this would likely be expected as there is no Wrapper code appended to a strategy.

Could you compose a very simple example of the structure used in NT7 so we can confirm that this is identical to what you had done that was already working?


I look forward to being of further assistance.

[Yandychang]

Regarding Abstract Class

Actually, On NT 7, it did not throw any errors, it compiled Fine... NT skipped adding the Ninjascript Generated Code... my NT7 version is 7.0.1000.30.

[NinjaTrader_Jesse]

Hello,

Thank you for the sample.

I do see that when you remove the generated code it allows it to compile in nt7. I am unsure in regard to design if this was expected or not, but in either case I have submitted this sample to development for further review to see if this can be moved to match nt7.

I look forward to being of further assistance.

[Yandychang]

I have not tried this yet, but I noticed that the file name generated by nt7 starts with @@... Maybe renaming the file and adding @@ in front of the name in NT8 makes a quick fix...

[NinjaTrader_Jesse]

Hello,

Where are you seeing a file name generated by nt7 that starts with @@?

@@ in NT8 would be to exclude a NinjaScript item, this is what occurs when you right click and exclude from compilation in the new editor.

For NinjaTrader 7 I would be unsure where you are seeing @@.

I look forward to being of further assistance.

[Yandychang]

Never mind then, it was a file I had excluded to be able to compile... I think it was NT 8