Ho to detect a new compile of a c# script?

Grasshopper
,
1

Hi all.

Give a simple class like:

private void RunScript(object x, object y, ref object A)
  {
    obj = new MyClass(this.Component);
  }

  // <Custom additional code> 
  public MyClass obj;

  public class MyClass{
    IGH_Component comp;
    public MyClass(IGH_Component Comp){
      comp = Comp;
    }
  }

That “obj” object can run methods internally autonomously. Load on the CPU.
I can manage that class easily from the main void RunScript.

But if, before stopping that object, I open the script editor, make some edit, and close (triggering a new compile of the c# component) … I’ll lose any connection to that object!
“comp” always return valid, even after re-compile.
My new “obj” object will be a new, different object (after recompile), and now I have no control over the previous one.

How to solve this?
Any suggestions? Workarounds?

2

What if the object is constructed upstream and passed to the script that is working on it. Like this:

Screenshot 2025-03-07 at 10.47.16 AM
Screenshot 2025-03-07 at 10.47.16 AM1920×1053 92.8 KB

test.gh (6.2 KB)

1 Like
3

Interesting!
Thanks!

I’ll be honest, I don’t remember the specific case for what was I needing this 1 year ago… but similar problems still occurs to me.

In the first c# script you removed the “public class Script_Instance : GH_ScriptInstance” and “private void RunScript()” sections, and built directly a class.
Then, you even used the output “classInstance” without being inside the usual “private void RunScript()” … How does it work? What’s going on?

And… a custom class/object can now exit a c# script component and go to another?
I think 7 couldn’t do this. Cool!

I’ll make some tests.

4

In the new C# scripting component, you don’t have to implement a GH_ScriptInstance. This was called SDK-mode on the legacy IronPython component. I made this consistent across languages. Both python and C# now support Script-mode (without GH_ScriptInstance class) and SDK-mode (with GH_ScriptInstance class).

As you know the GH_ScriptInstance is really powerful to implement before/after solve and preview handlers in grasshopper. The script-mode makes it easy to write C# code when these overrides are not necessary and you just want to put some logic together.

To match legacy behaviour, the C# component defaults to SDK-mode, and Python components default to Script-mode.

1 Like