Re: [dbus-cplusplus-devel] Problem with the DBus::MessageIter::operator>>( DBus::MessageIter & iter, DBus::Variant & val )

[Andreas V. <li...@br...>]

Am Tue, 6 Oct 2009 23:19:38 -0400 schrieb asdfffdsa:

Hello (what ever your name is),

is the source from the fdo.org GIT repository or that from
gitorious.org? I ask because the generator is different.

Could you send me a minimal example with Makefile, XML and source that
compiles? Then I try it on my system.

To be honest I didn't work much with Variant in the past. So I don't
see the problem from only looking on your source. I've to try it.

regards
	Andreas

> Hello, I am new to dbus-c++.  I am very enthusiastic about this
> project (and the dbus and hal projects).  I've installed dbus-c++
> from the Archlinux User Repository ( dbus-c++ 20090929-1 ).  I will
> be downloading the source over night to further inspect the problem
> (my ISP has a very strict usage policy).
> 
> I seem to be having a problem with the DBus::MessageIter::operator>>(
> DBus::MessageIter & iter, DBus::Variant & val ) function
> ( declaration is in types.h ).  I've used the "dbusxx-xml2cpp" binary
> to generate proxy pattern classes.
> 
> *Here is my code:*
> // halDeviceProxy is a variable of a dbusxx-xml2cpp-generated proxy
> class for the "org.freedesktop.Hal.device" interface
> ::DBus::Variant variant = halDeviceProxy.GetProperty(
> std::string(propertyName) );
> 
> 
> *Here is the dbusxx-xml2cpp-generated proxy code:*
> ::DBus::Variant GetProperty(const std::string& key)
> {
>         ::DBus::CallMessage call;
>         ::DBus::MessageIter wi = call.writer();
>         wi << key;
>         call.member("GetProperty");
>         ::DBus::Message ret = invoke_method(call);
>         ::DBus::MessageIter ri = ret.reader();
> 
>         ::DBus::Variant argout;
>         ri >> argout;  *// this line causes an exception to be thrown*
>         return argout;
> }
> 
> 
> *The "ri >> argout" call is causing the following error/exception:*
> terminate called after throwing an instance of
> 'DBus::ErrorInvalidArgs' what():  variant type expected
> Aborted
> 
> 
> Naturally, "ri >> argout" is passing in a variant type, so I'm not
> sure what the problem is.  The odd thing about this is that functions
> such as GetAllProperties() work fine (which returns a
> std::map<std::string,DBus::Variant>).
> 
> I will be looking over the source when I get a chance, but if anyone
> has any ideas in the mean time, it would be very helpful.