Re: [dbus-cplusplus-devel] DBus-C++ on_get_property

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

Am Wed, 22 Apr 2009 11:26:26 +0100 schrieb Markus Kohler:

> I found in properties.h the following code:
> 
> Message PropertiesAdaptor::Get(const CallMessage &call)
> {
>         [...]
>         Variant *value = interface->get_property(property_name);
> 
>         if (!value)
>                 throw ErrorFailed("requested property not found");
> 
>         on_get_property(*interface, property_name, *value);
> 
>         ReturnMessage reply(call);
> 
>         MessageIter wi = reply.writer();
> 
>         wi << *value;
>         return reply;
> }
> 
> If you make changes to value inside of on_get_property(...) it will
> be also written into the interface->get_property(property_name), i.e.
> changes in there will change the interface. Is this intended to be
> like this. I would have expected that inside on_get_property(...) you
> get the value that you can modify for the output to the client
> application only without changing the values in the interface. If the
> intention is the later the code should be:
> 
> Message PropertiesAdaptor::Get(const CallMessage &call)
> {
>         [...]
> -->    Variant value = *interface->get_property(property_name);
> 
>         if (!value)
>                 throw ErrorFailed("requested property not found");
> 
> -->    on_get_property(*interface, property_name, value);
> 
>         ReturnMessage reply(call);
> 
>         MessageIter wi = reply.writer();
> 
> -->    wi << value;
>         return reply;
> }
> 
> Comments?

Hello Markus,

currently I don't use properties, so I don't know it without deeper
investigation in this topic. To be honest I never used the "Variant"
type in my application. So as long that nobody writes unit tests I
couldn't check in the change.

I started to write some unit tests, but didn't yet commit it as I'm
again busy with another opensource project.

But if you create a bug report for it someone (I?) will have a look
later,

regards
Andreas