Listen/emit Multiple windows

[imseya18]

Hello,
i have basic code where i create a window and send it some data. I have a ready event emit from front when the page is ready so i can send data from my backend.
My problem is, when i create a window and emit the ready event, that triger the ready event from all window so my back get it from all window, and not just from the one i just created.
i thought it was possible to just listen/emit to specific webview but it looks like my code juste block/crash when im trying to do it.

I think i'm missing something.

event sent from front from each new window created:
  useEffect(() => {
    appWebview.emit(readyEvent, null);
    const unlisten = appWebview.listen<Bledevice>(listenEvent, (event) => {
      setDevice(event.payload);
    });
    return () => {
      unlisten.then((unlisten) => unlisten());
    };
  }, []);

Rust code

#[tauri::command(rename_all = "snake_case")]
async fn create_window(app: AppHandle, ble_device: Bledevice) -> Result<(), String> {
    let window_label = format!("window-{}", ble_device.address);
    let window = match app.webview_windows().get(&window_label) {
        None => {
           let window = tauri::WebviewWindowBuilder::new(&app, &window_label, WebviewUrl::App("#/info".into()))
                .decorations(false)
                .transparent(true)
                .resizable(false)
                .build()
                .unwrap();
            window
        }
        Some(window) => {
            window.set_focus().map_err(|e| e.to_string())?;
            return Ok(());
        }
    };

    window.clone().listen("ready", move |_| {
        window.emit("ble_device", ble_device.clone()).unwrap();
    });
    Ok(())
}

[FabianLars]

appWebview.emit(readyEvent, null); -> can you check if emitTo with the label set behaves more like what you desire?

[imseya18]

i tried this

    appWebview.emitTo(appWebview.label, "ready", null);
    const unlisten = appWebview.listen<Bledevice>("ble_device", (event) => {
      info("FRONT: RECEIVE ON: " + appWebview.label);
      setDevice(event.payload);
    });

my app just crash when i send the emit to the second window

[2025-03-05][12:50:47][ble_poc_lib::ble::ble_interaction][INFO] Starting scan on "hci0 (usb:v1D6Bp0246d0548)"
[2025-03-05][12:50:56][ble_poc_lib][INFO] BACK: RECEIVE FROM: window-40:DA:5C:C4:3A:A5
[2025-03-05][12:50:56][ble_poc_lib][INFO] BACK: EMITED FROM: window-40:DA:5C:C4:3A:A5
[2025-03-05][12:50:56][ble_poc_lib][INFO] BACK: RECEIVE FROM: window-40:DA:5C:C4:3A:A5
[2025-03-05][12:50:56][ble_poc_lib][INFO] BACK: EMITED FROM: window-40:DA:5C:C4:3A:A5
[2025-03-05][12:50:57][webview:value@user-script:14:275:38][INFO] FRONT: RECEIVE ON: window-40:DA:5C:C4:3A:A5
[2025-03-05][12:51:03][ble_poc_lib][INFO] BACK: RECEIVE FROM: window-44:5E:CD:34:96:F7
[2025-03-05][12:51:03][ble_poc_lib][INFO] BACK: EMITED FROM: window-44:5E:CD:34:96:F7

[FabianLars]

Hmm the logs don't really show anything relevant I think. Are you sure that crash comes from tauri and not your own code?

Do you think you can create a minimal reproduction project for this?

[imseya18]

Yes, i will try it tomorrow and keep you updated thanks for your time

[imseya18]

Let me know if i'm getting it right.
The emitTo function is "useless" for a front -> back communication as the listener are managed by the Tauri::Manager, and there is only one manager per App and not one by window right ?

So if i create a listener to the event "ready" each time i spawn a window the listener will not be attached to the window but to the app ?

so what i'm doing here:
#[tauri::command(rename_all = "snake_case")] async fn create_window(app: AppHandle, ble_device: Bledevice) -> Result<(), String> { window.clone().listen("ready", move |_| { window_clone.emit_to(window_clone.label(),"ble_device", &ble_clone).unwrap(); }); Ok(()) }

just create multiple listener for the ready event never mind the window that's send it ?

[imseya18]

look like i have a similar issue:
#9453