Comments on: Connecting C++ To Javascript Via Google’s V8

By: olsenc

olsenc — Tue, 27 Jan 2009 16:43:44 +0000

Whenever I get a value back from js into my c++ code I always check it’s type by casting it to the type I think it should be. I would try something along the lines of:
v8::Handle result = function->Call(object, 0, NULL);
v8::Handle resultAsAFunction = v8::Handle::Cast(result);

now you can check to see if the variable is null or undefined:
if (resultAsAFunction.IsEmpty() || resultAsAFunction->IsUndefined())
{ … }

Try that and see if that gives you any clues as to whether or not you actually have a function or not. My first inclination was that what you actually have is an object not a function and the method GetName is not defined on a v8 Object.

Corey

By: Tom Hagman

Tom Hagman — Thu, 22 Jan 2009 22:58:24 +0000

Corey,

I’ve been playing with the V8 engine for a few days.

I’m builting a COM+ ATL server to expose the javascript engine functionality. I’m having some trouble getting the name of a object being returned by a function.

Here’s JS sample:
function CRV(pName1, pValue1)
{
this.Name = pName1;
this.Value = pValue1;
}

function doit()
{
var crv = new CRValue(‘Col1′, ‘Val1′);
return crv;
}

doit();

When doit() returns a CRV, I need to know that the type is ‘CRV’.

This compiles, but kills the engine on the GetName();
Local jsfunc = result->ToFunction();
Handle hFunctionName = jsfunc->GetName();

where result is return from script->Run();

Any suggestions would be appreciated.

Thanks,
Tom