Detect if addon is already started

[johnok]

Hello,

Is there a way to detect if my addon is already started ? I would like to force user to have only one addon started.

Thanks for the help !

Sebastien

[NinjaTrader_Kate]

Hello johnok,

Thank you for your inquiry.

All authorized addons will be automatically started when the platform loads - what is the use case here? You can only have one instance of the same add-on compiled and running simultaneously, so I'm unsure what you mean. Are you trying to force the use of only your add-on?

Thanks in advance; I look forward to assisting you further.

[johnok]

Thanks for your answer.

In my case, i've an addon who can help user to manager there positions. But if the user start multiple instance of this addon, managed positions could be impacted by all instance in same time and it's not good.

To avoid this impact, i'm searching if my addon can check at start with lockfile ? Mutex ? or maybe a Ninjascript attribute if this addon is already started once and cancel the start.

Thanks

[NinjaTrader_Kate]

Hello johnok,

Thank you for your reply.

If there are multiple installed addons with the same class names, only the first one alphabetically will be loaded. The other instances of the add-on would be ignored. There can only be one instance of the same addon running at once.

Please let us know if we may be of further assistance to you.

[johnok]

Oh, that's was my mistake, the problem seems to be about event cleaning and not multiple addon instance.

The event OnExecutionUpdate is called multiple times after re-compilation of my addon. I have an Addon with xaml code and i'm using "Closing" method to unbind this event but the event seem to be duplicated and not cleaned because my addon is not stopped.

I'm now searching how to check if event are already binded or unbind properly.

[johnok]

And when i try to use Cleanup method, i get the error message: "No method has been found for the substitution" (in french).

I don't know where to place this method who could maybe do the job.

[NinjaTrader_Kate]

Hello johnok,

Thank you for your reply.

In an add-on, you would want to unsubscribe from any event handlers and dispose of any resources that need it in OnWindowDestroyed(). From our help guide:

// Will be called as a new NTWindow is destroyed. It will be called in the thread of that window
protected override void OnWindowDestroyed(Window window)
{
  if (addOnFrameworkMenuItem != null && window is ControlCenter)
  {
      if (existingMenuItemInControlCenter != null && existingMenuItemInControlCenter.Items.Contains(addOnFrameworkMenuItem))
          existingMenuItemInControlCenter.Items.Remove(addOnFrameworkMenuItem);

      addOnFrameworkMenuItem.Click -= OnMenuItemClick;
      addOnFrameworkMenuItem = null;
  }
}

I would suggest reviewing this section of the help guide on creating an addon:

https://ninjatrader.com/support/helpGuides/nt8/creating_your_own_addon_window.htm

Please let us know if we may be of further assistance to you.