Trouble calling script function from app

[Cyprias]

Hi again,

I'm trying to call a script function before disposing a engine so the script knows its being stopped. To do so I'm first trying the example to call a script function.

Creating and executing the engine.

Script runScript(ScriptPackage package)
{
	var flags = V8ScriptEngineFlags.EnableDynamicModuleImports;
	V8ScriptEngine engine = new V8ScriptEngine(flags);
	engine.DocumentSettings.AccessFlags |= DocumentAccessFlags.EnableFileLoading;
	string contents = System.IO.File.ReadAllText(package.main);
	DocumentLoader.Default.DiscardCachedDocuments();
	
	var script = new Script(package.name, package.directory);
	script.engine = engine;
	
	engine.Execute(new DocumentInfo { Category = ModuleCategory.Standard }, contents);
	return script;
}

Then in the script I have the a function.

function myFunc(x, y, z) {
    return { xValue: x, yValue: y, zValue: z };
}

Elsewhere in my app when I call my script.Dispose() function.

public class Script
{
	public V8ScriptEngine engine;
	public void Dispose()
	{
		// Where I would call a script function to notify of stopping.
		var yValue = engine.Script.myFunc(1, 2.0, "three").yValue;
		print("yValue " + yValue);
		engine.Dispose();
	}
}

I get in my log

7/26/2026 1:37:42 AM
Error: TypeError: Method or property not found
Source: ClearScript.Core
Stack:    at Microsoft.ClearScript.ScriptItem.ThrowLastScriptError()
   at CallSite.Target(Closure , CallSite , Object , Int32 , Double , String )
   at System.Dynamic.UpdateDelegates.UpdateAndExecute4[T0,T1,T2,T3,TRet](CallSite site, T0 arg0, T1 arg1, T2 arg2, T3 arg3)
   at App.PluginCore.Script.Dispose() in C:\Games\App\PluginCore.cs:line 1538
   at App.PluginCore.lstScripts_Selected(Object sender, Int32 row, Int32 col) in C:\Games\App\PluginCore.cs:line 1806
ErrorDetails: TypeError: Method or property not found

Then the script stops as expected.

I tried changing the script function to

myFunc = function(x, y, z) {
    return { xValue: x, yValue: y, zValue: z };
};

But then I get a error on script load.

7/26/2026 2:10:22 AM
Error: ReferenceError: myFunc is not defined
Source: ClearScript.V8
Stack:    at Microsoft.ClearScript.V8.SplitProxy.V8SplitProxyNative.Invoke[TArg](Action`2 action, TArg& arg)
   at Microsoft.ClearScript.V8.SplitProxy.V8ContextProxyImpl.InvokeWithLock[TArg](Action`1 action, TArg& arg)
   at Microsoft.ClearScript.V8.V8ScriptEngine.ScriptInvoke[TArg,TResult](Func`2 func, TArg& arg)
   at Microsoft.ClearScript.V8.V8ScriptEngine.Execute(UniqueDocumentInfo documentInfo, String code, Boolean evaluate)
   at Microsoft.ClearScript.ScriptEngine.Execute(DocumentInfo documentInfo, String code)
   at App.PluginCore.runScript(ScriptPackage package) in C:\Games\App\PluginCore.cs:line 1226
   at App.PluginCore.lstScripts_Selected(Object sender, Int32 row, Int32 col) in C:\Games\App\PluginCore.cs:line 1805
Inner: ReferenceError: myFunc is not defined
Inner Stack:    at Microsoft.ClearScript.V8.SplitProxy.V8SplitProxyNative.Invoke[TResult,TArg](Func`3 func, TArg& arg)
   at Microsoft.ClearScript.V8.SplitProxy.V8ContextProxyImpl.Execute(UniqueDocumentInfo documentInfo, String code, Boolean evaluate)
   at Microsoft.ClearScript.V8.V8ScriptEngine.ExecuteRaw(UniqueDocumentInfo documentInfo, String code, Boolean evaluate)
   at Microsoft.ClearScript.V8.V8ScriptEngine.ExecuteInternal(UniqueDocumentInfo documentInfo, String code, Boolean evaluate)
   at Microsoft.ClearScript.V8.V8ScriptEngine.<>c.<Execute>b__139_0(ValueTuple`4 ctx)
   at Microsoft.ClearScript.ScriptEngine.ScriptInvokeInternal[TArg,TResult](Func`2 func, TArg& arg)
   at Microsoft.ClearScript.V8.V8ScriptEngine.<>c__148`2.<ScriptInvoke>b__148_0(StructPtr`1 pCtx)
   at Microsoft.ClearScript.V8.SplitProxy.V8ContextProxyImpl.<>c__14`1.<InvokeWithLock>b__14_0(IntPtr pCtx)
   at Microsoft.ClearScript.V8.SplitProxy.V8SplitProxyManaged.InvokeHostActionWithArg(IntPtr pAction, IntPtr pArg)
ErrorDetails: ReferenceError: myFunc is not defined
    at Module:6:8

From reading some other issue threads I'm guessing the module loading is messing up the calling of functions? Is there a better way to accomplish my goal?

[ClearScriptLib]

Hi @Cyprias,

I'm guessing the module loading is messing up the calling of functions?

It doesn't affect function calling, but it does change the effect of declaring a function or variable in the outermost scope. In a normal script (DocumentCategory.Script) doing so adds the function or variable as a property of the global object. In a module, it doesn't, so engine.Script.myFunc remains undefined.

Is there a better way to accomplish my goal?

Almost certainly, but the solution depends on your goal.

• If you simply execute the code as a normal script instead of a module, you'll get the behavior you're expecting.
• If you must execute the code as a module, you have several options:
  • The module could explicitly attach the function to the global object: globalThis.myFunc = function (x, y, z) { ... };
  • The module could return the function via import.meta.setResult. See here for an example.
  • The module could export the function. Your host could then gain access to the function by importing it. There are multiple ways to do that. Let us know if you need details.

Good luck!

[Cyprias]

The globalThis method worked. Thank you so much. You're the best.