Re: [Swig-user] python wrapper to c++ library with abstract classes

[Brian C. <co...@ey...>]

Oops, need to invoke base class ctor:

class SubscriberListener( SessionListener):
   def __init__(self):
        SessionListener.__init__(self)

-Brian

On 4/24/09 7:45 AM, "Christophe Dupre" <chr...@vh...> wrote:

Thanks Brian. That seems to work, although I now hit  a new hurdle.

Here is my new class which inherits from SessionListener.
class SubscriberListener( SessionListener):
                def __init__(self):
                                pass
                def OnSessionEvent( self, session, msg ):
                                print "hello world"


listener = SubscriberListener()
session = Session()

If I call:
                session.SetSessionListener(listener)
I get the following error:
                Traceback (most recent call last):
                 File "<pyshell#62>", line 1, in <module>
                   session.SetSessionListener(listener)
                 File "C:\Python26\swig\Examples\python\PubSub\include\vhpubsub\example.py", line 215, in SetSessionListener
                   def SetSessionListener(self, *args): return _example.Session_SetSessionListener(self, *args)
                TypeError: in method 'Session_SetSessionListener', argument 2 of type 'vhpubsub::SessionListener *'

vhpubsub is the namespace from the c++ library.

Any idea?

Thanks,

Christophe




From: Brian Cole [mailto:co...@ey...]
Sent: 23 April 2009 17:35
To: Miklos Vajna
Cc: swi...@li...
Subject: Re: [Swig-user] python wrapper to c++ library with abstract classes

Python is falling through to the default swig __init__ implementation. You need to specify a constructor in your subclass:

class test(SessionListener):
    i = 9
    def __init__(self):
        pass
    def f(self):
        return i

You'll probably have to override "OnSessionEvent" as well, but I'm guessing that's what your 'f' method is.

-Brian

On 4/23/09 9:22 AM, "Miklos Vajna" <vm...@fr...> wrote:
On Thu, Apr 23, 2009 at 08:00:48AM -0500, Christophe Dupre <chr...@vh...> wrote:
> In the library, the is a class which looks like this:
>
> class SessionListener
>
> {
>
> public:
>
>       virtual ~SessionListener() {}
>
>       virtual void OnSessionEvent(Session* session, const SessionEvent*
> event) = 0; // throw()
>
>
>
> protected:
>
>       SessionListener() {}
>
> };

Given that I guess you want to pass the class instance back to the C++
library later, you'll need the director feature. Have you enable it?

In the interface file you'll need something like this:

----
%module(directors="1") <your module name>

// generate directors for all classes that have virtual methods
%feature("director");
----
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