[C++-sig] Problems using wrapper.hpp to override virtual functions

[Roman Yakovenko]

On Jan 17, 2008 1:18 AM, Tim Spens <t_spens at yahoo.com> wrote:
> Here is the simplest example of what I'm trying to do, I hope this is enough the complete
> project to quite large.  I'm using wrapper.hpp so that I can use a python handler to handle
> callbacks from the c++ code.
>
>
>       //c++ pure virtual function definition
>       virtual void handle(const CLIENT::client_response & rsp) = 0;
>
>       //c++ wrapper for virtual function "handle"
>       virtual void handle(client_response const & rsp)
>       {
>           if(override func_handle = this->get_override("handle")){
>                  //I cannot get this section of code to run, from what I understand this would be the callback into python?
>               func_handle(boost::ref(rsp));
>               cout << "here handle in python" << endl;}
>           else{
>                  //I currently have a c++ handler which is called here, I would like to use the python handler though.
>               this->python_handler::handle(boost::ref(rsp));
>               cout << "here handle in c++" << endl;}
>       }
>
>       BOOST_PYTHON_MODULE(libclientpy)
>       {
>           class_<python_client_handler_wrapper, bases<client_handler>, boost::noncopyable >("python_client_handler", init<>())
>               .def("handle", &client_handler::handle);
>       }
>
> #PYTHON CODE
> import libclientpy
> handler = libclientpy.python_handler()
> client = libclientpy.client(handler, '127.0.0.1', 7900)
>
> class callback(handler):
>     def handle(self, x):
>         print 'handle python'
>
> azc = addZapCallback()
>
> Traceback (most recent call last):
>   File "./test_client.py", line 304, in <module>
>     class callback(handler):
> Boost.Python.ArgumentError: Error when calling the metaclass bases
>     Python argument types in
>     python_client_handler.__init__(python_client_handler, str, tuple, dict)
> did not match C++ signature:
>     __init__(_object*)
>
>
> I am unsure what is happening here.  I cannot even find a __init__ function in my python_client_handler that has the said arguments? __init__(python_client_handler, str, tuple, dict)
>
> Any ideas?

Small complete example helps.

you have to call __init__ method of exposed C++ class


class callback(handler):
    def __init__( self ):
        handler.__init__( self )
    def handle(self, x):
        print 'handle python'

HTH

-- 
Roman Yakovenko
C++ Python language binding
http://www.language-binding.net/