From kde-devel  Tue Oct 14 10:59:38 2008
From: Richard Dale <rdale () foton ! es>
Date: Tue, 14 Oct 2008 10:59:38 +0000
To: kde-devel
Subject: Re: port of pyjamas to pykde / khtml - issues and observations with
Message-Id: <200810141159.38837.rdale () foton ! es>
X-MARC-Message: https://marc.info/?l=kde-devel&m=122398222122025

On Monday 13 October 2008 21:43:17 Luke Kenneth Casson Leighton wrote:
> > also, crucially - absolutely, absolutely crucially: you can't do a
> > "compare" against nodes.  the objects are potentially different.  and
>
> folks, hi,
>
> this is a show-stopper, and needs to be fixed.  i tried creating a
> workaround wrapper class, by extending pykhtml's dom.py, with a view
> to making it the "central" location - choke-point - through which the
> creation of all Node and Node-derived objects go, but there doesn't
> exist a function in the underlying DOM model to uniquely identify the
> c++ objects.  not the wrappers _around_ the c++ objects, the c++
> objects themselves.
The best place for this sort of thing is to post to the kde-bindings@kde.org 
list, and talk with Simon Edwards the PyKDE maintainer.

However, you are right in this case that the problem is that there isn't 
sufficient RTTI information in the C++ api to identify what class an instance 
is. Here is a snippet of code from the Ruby bindings that attempts to identify 
DOM::Node classes. But there are many other classes which can't be identified.

	} else if (strcmp(smoke->classes[classId].className, "DOM::Node") == 0) {
		DOM::Node * node = (DOM::Node *) smoke->cast(ptr, classId, smoke-
>idClass("DOM::Node"));
		switch (node->nodeType()) {
		case DOM::Node::ELEMENT_NODE:
			if (((DOM::Element*)node)->isHTMLElement()) {
				return "DOM::HTMLElement";
			} else {
				return "DOM::Element";
			}
		case DOM::Node::ATTRIBUTE_NODE:
			return "DOM::Attr";
		case DOM::Node::TEXT_NODE:
			return "DOM::Text";
		case DOM::Node::CDATA_SECTION_NODE:
			return "DOM::CDATASection";
		case DOM::Node::ENTITY_REFERENCE_NODE:
			return "DOM::EntityReference";
		case DOM::Node::ENTITY_NODE:
			return "DOM::Entity";
		case DOM::Node::PROCESSING_INSTRUCTION_NODE:
			return "DOM::ProcessingInstruction";
		case DOM::Node::COMMENT_NODE:
			return "DOM::Comment";
		case DOM::Node::DOCUMENT_NODE:
			return "DOM::Document";
		case DOM::Node::DOCUMENT_TYPE_NODE:
			return "DOM::DocumentType";
		case DOM::Node::DOCUMENT_FRAGMENT_NODE:
			return "DOM::DocumentFragment";
		case DOM::Node::NOTATION_NODE:
			return "DOM::Notation";
		}
	}

Maybe the code has changed since I looked at it and KDE3, I haven't had a 
really careful look at it for a while. The KHTML guys might be able to help 
best.

-- Richard
 
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