[python-win32] accessing application object from OnConnectionmethod in another Class

[Mark Hammond]

> If you look at the example demo "ExcelAddin" that come with win32all,

FYI,
http://cvs.sourceforge.net/viewcvs.py/spambayes/spambayes/Outlook2000/addin.
py is a complete Office Addin, and has jumped through many hoops.

>
> def OnConnection(self, application, connectMode, addin, custom):
>      self.appHostApp = application
>      btnMyButton = self.toolbarButton =
> DispatchWithEvents(btnMyButton, ButtonEvent)

Just ignore the man behind the curtain :)  Do it the way you would normally
do it!

  btnMyButton._application = self

should just store it in an instance variable.  Obviously you will want to
avoid conflict with Word's attribute names - we first try and set the
attribute to word, and it that fails, store it in the instance.

Another alterative is to just add your own method to the event class:

class ButtonEvent:
  # as normal
  def _MyFunkyMethod(self, whatever):
   ...

btnMyButton = DispatchWithEvents(btnMyButton, ButtonEvent)
btnMyButton._MyFunkyMethod(self)

Note that you need to be very careful with DispatchWithEvents and circular
references.  These DWI objects have a reference to the original object (eg,
the Excel object the events are being sourced from), and the original object
has a reference to the DWI object (as that is where it is delivering
events).

Eg,
a = Dispatch("Word.App")
e = DispatchWithEvents(a, myclass)

'e' has a reference to 'a', and 'a' has a reference to 'e' - this is a
circular reference that must be manually broken.

However:
a = Dispatch("Word.App")
e = WithEvents(a)

Avoids that circle - 'a' still holds a reference to 'e', but 'e' holds no
reference to a.  Thus, as soon as a or e go out of scope, it all still
destructs correctly.

That is one hoop SpamBayes had to jump through to stop certain events
leaking.

> to name a few. I have also spent some time in the MSDN and Google and
> still am confused. Have ordered Marks book "Python programming on
> win32" but it will only be here in 10 days (i count the minutes). so

Mark.