IDocHostUIHandler GetExternal question   

If I implement IDocHostUIHandler::GetExternal, can the IDispatch
object I return, have methods that return other IDispatch objects, and
can objects from JavaScript be passed as parameters as well?

So in JavaScript I would do something like this:

obj = window.external.createMyObject();
obj.DoSomething();

Does JavaScript just treat all objects as IDispatch, if not, how does
it know what type of object/variable the "createMyObject" function
returned?  Well, I guess I might know the answer to that, since COM
uses variant params, and my Invoke function sets the variant type that
it returns... I guess that is how JavaScript knows the variable type,
right?

Maybe this is a JavaScript question, so if I don't get an answer here,
I'll try one of those groups.

By the way, I'm using C++ to implement IDocHostUIHandler (which is why
I know how the variant type gets set by the Invoke function, not set
by the run-time engine for you).

date: Wed, 17 Oct 2007 15:35:28 -0700   author:   unknown

Re: IDocHostUIHandler GetExternal question   

eselk@surfbest.net wrote:
> If I implement IDocHostUIHandler::GetExternal, can the IDispatch
> object I return, have methods that return other IDispatch objects, and
> can objects from JavaScript be passed as parameters as well?

Yes and yes.

> So in JavaScript I would do something like this:
>
> obj = window.external.createMyObject();
> obj.DoSomething();

Quite possible.

> Does JavaScript just treat all objects as IDispatch

Yes.

> how does
> it know what type of object/variable the "createMyObject" function
> returned?

It doesn't know nor care.

> Well, I guess I might know the answer to that, since COM
> uses variant params, and my Invoke function sets the variant type that
> it returns... I guess that is how JavaScript knows the variable type,
> right?

Well, that's how it distinguishes an object from a primitive value like 
an integer or a string. But all objects look the same to it (stored in 
VARIANT of type VT_DISPATCH).
-- 
With best wishes,
    Igor Tandetnik

With sufficient thrust, pigs fly just fine. However, this is not 
necessarily a good idea. It is hard to be sure where they are going to 
land, and it could be dangerous sitting under them as they fly 
overhead. -- RFC 1925

date: Wed, 17 Oct 2007 18:45:57 -0400   author:   Igor Tandetnik