How to get a IHTMLElement pointer to the <object> tag hosting an activex control

I have an ActiveX control generated by the FireBreath framework (http://firebreath.org). I need to get a reference to the <object> tag in the page that hosts the plugin from C++.

If I were using NPAPI, I would use the NPNVPluginElementNPObject constant with NPN_GetValue.

so to make sure I am being clear, say I have the following in the page:

<object id="testPlugin" type="application/x-someplugin" width="100%" height="100%"></object>

I want to get a reference to the plugin like I would if I used document.getElementById("testPlugin"), except from within the C++ code of the activex control that is inserted for that mimetype.

Please note that passing the id in as a <param>开发者_如何学Python is not a good option for me, but if there is a way to get the ID from inside the activex control that may work.

edit: I am considering using getElementsByTagName and trying to find it through the DOM, but it would be difficult to tell the difference between two instances of the same plugin.

Thanks to FireBreath contributor jtojanen from Finland, we finally have a solution.

The first thing is that the COM object must be registered as "Apartment", not "Single" (in the registry). Otherwise, this will not work; seems to be a bug in COM.

Then anywhere after SetClientSite is called, you can do the following:

CComQIPtr<IOleControlSite> site(m_spClientSite);
CComPtr<IDispatch> dispatch;
site->GetExtendedControl(&dispatch);
CComQIPtr<IHTMLElement2> htmlElement = dispatch;

Hope this saves someone some time; it's taken me almost 2 years to find someone who could answer this for me.

The object in htmlElement will be the <object> tag that wraps your plugin; so if you queryInterface for any of your interfaces, it should succeed, but it may not actually literally be your object, it will likely be a wrapper to your object.

In C#:

    public int SetSite(object site)
    {
        if (site != null)
        {
            var oleControl = (IOleControlSite)site;
            object oHtmlElement;
            oleControl.GetExtendedControl(out oHtmlElement);
            var htmlElement = (IHTMLElement2)oHtmlElement;
            ...
        }
    }