"&mut self" function parameter in autogenerated trait

[jwinarske]

Hi. Thanks for the great work.

Is there an option to indicate a trait function should have a "&mut self" parameter opposed to the default "&self"?

Such that one doesn't have to post edit the auto-generated file.

Thanks!

[diwic]

Hi,

Could you elaborate on which use case this would be helpful for you? What parameters are you running codegen with?

[jwinarske]

I'm using Default::default() for options. It's generating the server interface, which I want. I have it all wired together and am able to make calls, generate signals, and get responses via D-Feet.

Xml snippet:

        <method name="GetProfile">
            <arg name="profile" type="s" direction="out"/>
        </method>
        <method name="SetProfile">
            <arg name="profile" type="s" direction="in"/>
        </method>
        <signal name="ProfileSwitched">
            <arg name="profile" type="s"/>
        </signal>

With a generated interface looking like this:

pub trait MyConfig {
    fn get_profile(&self) -> Result<String, tree::MethodErr>;
    fn set_profile(&self, profile: &str) -> Result<(), tree::MethodErr>;
}

The following edit (+ others) is required to make the member variable mutable:

pub trait MyConfig {
    fn get_profile(&self) -> Result<String, tree::MethodErr>;
    fn set_profile(&mut self, profile: &str) -> Result<(), tree::MethodErr>;
}

Then implementing as

impl MyConfig for ProfileService {
    fn get_active_profile(&self) -> Result<String, MethodErr> {
        Ok(self.get_profile().clone())
    }
    fn set_active_profile(&mut self, profile: &str) -> Result<(), MethodErr> {
        Ok(self.set_profile(profile)) // writes self member variable
    }

Maybe there is a better way?

[diwic]

The problem here is that the way dbus-tree is designed, it does not have access to &mut self, only &self when it's supposed to call the method.
This and other limitations have been resolved in dbus-crossroads, but there is no codegen for that (yet). I should probably write something, but it's fairly ergonomic to write server code without codegen in dbus-crossroads...

[jwinarske]

I see. I'll take a look at dbus-crossroads. Thanks!

[diwic]

Hi @jwinarske!

I've written an implementation of codegen for dbus-crossroads now, just pushed to git master. Would you like to try it out and see if it fits your needs? When using the crossroads option, the trait will take &mut self instead of &self.

[jwinarske]

I just changed it be an "include", which resolves it for me.

Do you have an example of using crossroads with Tokio by any chance?

[diwic]

I just changed it be an "include", which resolves it for me.

Sorry, could you explain what you mean by this?

Do you have an example of using crossroads with Tokio by any chance?

https://github.com/diwic/dbus-rs/blob/master/dbus-tokio/examples/tokio_adv_server_cr.rs and https://github.com/diwic/dbus-rs/blob/master/dbus-tokio/examples/tokio_server_cr.rs
Neither uses codegen (yet).

[jwinarske]

include!("config_service/com_example_config.rs");

vs

mod com_example_config;

This is what I have so far (not tested): simple-service

[diwic]

@jwinarske Here's what I did to make your code compile: https://gist.github.com/diwic/ea2760b24a6246cb707e880188553363

[jwinarske]

Thanks David!