Excel RTD server in Python not updating data

To work around this problem I've created a new project on github for pythoncom excel types:

https://github.com/pyxll/exceltypes

This includes a slightly modified version of excelRTDServer.py that uses the new type PyIRTDUpdateEvent instead of the win32com makepy wrapper, and so it now works in Excel 2010 (look for the comments 'EXCELTYPES_MODIFICATION' in exceltypes/demos/excelRTDServer.py).

To build the project you will need visual studio installed (it won't build with gcc) and you can build it using the setup.py included in the project as follows:

python setup.py install

If you need to force it to use visual studio instead of gcc use the "--compiler=msvc" option, if you're using anaconda for example. If you want to use Visual Studio 2012 instead of the default 2010 add the following lines to setup.py:

from distutils import msvc9compiler
msvc9compiler.VERSION = 11

I think you may be out of luck.

According to the author of excelRTDServer.py in a recent python-win32 thread:

^{The message that this is in response to describes your exact problem, and it's recent, so maybe you already got this info directly, but in case you didn't...}

I fear that things with IRTDUpdateEvent have changed with recent versions of excel (since Excel 2007? I guess that's not so 'recent' anymore...).

While hunting around for news of interface changes, I came across this thread in a java forum:

http://www.nevaobject.com/phpbb3/viewtopic.php?t=516

The part that worries me is this comment:

"Apparently in Excel 12 (Excel 2007) the RTD callback object that implements dual IRTDUpdateEvent interface throws exception (generic COM exception 0x80020009) when is called via IDispatch. If you use v-table binding the call to UpdateNotify succeeds. I don't really know whether it is a bug in Excel 12 or a feature."

So far I haven't been able to confirm this against the MSDN information... But if this is true, it does explain the problem being seen. Many older examples on the web, and pywin32+makepy treat this interface as IDispatch, and wrap it accordingly.

I don't think we can fix this with pywin32 as it is right now. My understanding is that it relies on IDispatch support. May need to look at comtypes (http://starship.python.net/crew/theller/comtypes/) to wrap the (new?) IRTDUpdateEvent objects, or maybe a C extension. :(