Autorun Addon

[johnok]

Hello,

Is There a method to run an Addon automatically at Ninjatrader start ?

Thanks !

[kevinenergy]

Hi Johnok.

I had an issue with debugging an addon just last week and made this very basic and simple addon to test the lifecycle of an addon you might find useful. It prints out its status as it transitions between states. The numerical value is the hashcode of the addon, so you can identify which ones are being instantiated and which are being destructed.

To Answer your question, addons are automatically detected and started when Ninjatrader starts (or when recompile happens) and they exist as Singletons for the lifetime of the app process (or until a recompile happens: one starts and the old one is destroyed).

NB: Addons are started before the output window appears so you'll need to do rebuilds to observe the output on my test addon. If you do continuous rebuilds you'll see a new addon starting up and the old one being deconstructed by the garbage collector.

One thing I will warn you about is that the AddonBase class constructor calls the OnStateChange method of your Addon method BEFORE it calls the constructor of your addon. so make sure you don't use the constructor of your addon for instantiating instances of other classes you may require. I spent days trying to figure out why my addon wasn't working and it was because my I was using the constructor of my addon for instantiating things and they were being utilised via the base class before they my constructor had been called, so my instances had not yet been created. This resulted in a NullReference exception and a silent failure; took a couple of days to figure out what was going on.

Hope this helps.

Kevin.