question: is this dbus signal handling code idiomatic? about dbus-rs HOT 6 CLOSED

Is something similar possible in Rust with this dbus library?

Not currently, but that's mostly because nobody has implemented it yet. One problem is that Rust is torn between the older "rustcserialize" and the newer "serde", and I have had problems making up my mind w r t which one to support (or both).

Or is iterating through the individual message arguments really the idiomatic way?

Yes - that's basically what you do - or use get1, get2, or get3, but you would need a get6 so it doesn't work for you.

What looks a bit inconsistent in your code is that you return a Option<ServiceBrowserItemNew> but there is no way to return None from the function - instead you panic on message not matching.
Whether to unwrap or to do proper error handling is up to you, but this seems like a mix.

You do raise a valid point in that this could be done in a more ergonomic way. I'll give this a thought.

from dbus-rs.

Ok, so I've added an iter::read method now. Using it your code would look like:

fn service_browser_item_new_msg(m: &dbus::Message) -> Result<ServiceBrowserItemNew, TypeMismatchError> {
   let mut iter = m.iter_init();
   Ok(ServiceBrowserItemNew {
       interface: try!(iter.read()),
       protocol: try!(iter.read()),
       name: try!(iter.read::<&str>()).into(),
       item_type: try!(iter.read::<&str>()).into(),
       domain: try!(iter.read::<&str>()).into(),
       flags: try!(iter.read()),
   })
}

Could you give it a try and see if it works the way I expect it to? If so I might do a new release with this function in (and might even steal your struct definition and use as an example, with your permission).

from dbus-rs.

Thanks a bunch for the quick reply and fix! I’ll be happy to test that tomorrow. Do you happen to have a pointer as to how I can use the git version of your dbus library in my Cargo.toml in a way that includes the change you mentioned?

from dbus-rs.

Like this:

[dependencies]
dbus = { git = "https://github.com/diwic/dbus-rs" }

from dbus-rs.

Thanks a bunch! I can confirm that the following works for me:

fn service_browser_item_new_msg(m: &dbus::Message)
                                -> Result<ServiceBrowserItemNew, dbus::arg::TypeMismatchError> {
    let mut iter = m.iter_init();
    Ok(ServiceBrowserItemNew {
        interface: try!(iter.read()),
        protocol: try!(iter.read()),
        name: try!(iter.read()),
        item_type: try!(iter.read()),
        domain: try!(iter.read()),
        flags: try!(iter.read()),
    })
}

Feel free to use that in the documentation.

from dbus-rs.

👍

Now released as v0.3.4.

from dbus-rs.