RE: Confusing about DBus API specification

[Dan Williams <dcbw redhat com>]

On Thu, 2010-04-29 at 21:33 -0700, Nguyen Canh Toan wrote:
> Dear Dan,
> 
> I do understand these fundamental concepts. Thank for your useful tutorial
> anyway.
> 
> I think my problem is I do not understand object as well as interface
> hierarchy exposed by NetworkManager DBus service.
> 
> According to API spec here
> (http://projects.gnome.org/NetworkManager/developers/spec-07.html#org.freede
> sktop.NetworkManager) and
> (http://live.gnome.org/NetworkManager/SystemSetting). I understand it as
> below:
> 
> 1. Service DBus named org.freedesktop.NetworkManagerSystemSetting and
> org.freedesktop.NetworkManagerUserSetting is one which I need to connect to
> inorder to get connection configuration.

Right, these are the service names/bus names that you need to talk to.

> 2. Get org.freedesktop.NetworkManagerSettings interface of service proxy

Correct; *both* services implement this common interface, since they
provide essentially the same information.  This way you only write the
code once, and you can talk to both services easily.

> 3. Invoke ListConnection() on returned interface.

I think you mean ListConnections(), but yes.

> It seems that your API spec isn't very clear so newcomers, like me, get
> confused when doing with this.

Yeah, I think what would be helpful is a general overview in the spec or
such about how the pieces fit together, possibly with a diagram and some
code examples.  I've done a bit of that and I'm about to post something
to my blog, which we can then rework into some documentation.  There are
various pages around that explain things, but mostly general overviews
and concepts and not really with code examples.  Here's one I whipped up
yesterday:

http://cgit.freedesktop.org/NetworkManager/NetworkManager/tree/examples/python/list-connections.py

There's a lot of improvement possible here, especially with examples.

> Please instruct me how to get used particularly this service. Or please make
> your spec more clearly.

I shall try.  Contributions and constructive criticism welcome, like
you've done above by pointing out that it's not clear how to talk to the
settings services.

Dan