npm-reflector-electron-MQTT-ipc-main

A reflector between an MQTT messaging environment and Electron IPC (main process). Messages published to MQTT (topic IPSME) are forwarded to every registered renderer window, and messages sent from a renderer are published back to MQTT. Duplicate reflections are suppressed via @ipsme/msgcache-dedup.

The MQTT connection itself is provided by @ipsme/msgenv-mqtt (broker mqtt://localhost:1883 by default).

IPSME — Idempotent Publish/Subscribe Messaging Environment

https://dl.acm.org/doi/abs/10.1145/3458307.3460966

main.js | electron.js

//-------------------------------------------------------------------------------------------------
// reflector mqtt <-> ipc

const { Reflector_IPC_main } = require('@ipsme/reflector-electron-mqtt-ipc-main');
const { ipcMain } = require('electron');

const reflector_IPC_main_ = new Reflector_IPC_main(ipcMain);
reflector_IPC_main_.subscribe();

//-------------------------------------------------------------------------------------------------

function createWindow() {
	// Create the browser window.
	const win = new BrowserWindow({
		// ...
		webPreferences: {
			// nodeIntegration: true,
			preload: __dirname + '/preload.js'
		},
	});

	// ...

	reflector_IPC_main_.add_window(win);

	win.on('closed', () => {
		reflector_IPC_main_.remove_window(win);
		// ...
	});
}

//-------------------------------------------------------------------------------------------------
// preload.js

// https://github.com/electron/electron/issues/9920#issuecomment-947170941

const { contextBridge, ipcRenderer } = require("electron");

// As an example, here we use the exposeInMainWorld API to expose the IPC renderer
// to the main window. They'll be accessible at "window.ipc_reflector".
process.once("loaded", () => {
    contextBridge.exposeInMainWorld('ipc_reflector',
		{
			// https://github.com/electron/electron/issues/21437#issuecomment-573522360
			send: (msg) => ipcRenderer.send('ipc-reflector-to-main', msg),
			recv: (fn) => {
				// Deliberately strip event as it includes `sender`
				ipcRenderer.on('ipc-reflector-to-window', (event, ...args) => fn(...args));
			}
		}
	);
});

Logging

Logging uses @knev/bitlogr (3.x). The reflector's labels (Reflector_IPC_main, DUPS, CXNS, REFL) start above the bits used by @ipsme/msgenv-mqtt (CONNECTIONS, REFLECTION) on the shared LOGR instance, so they can be toggled independently:

Reflector_IPC_main.options = { logr: { REFL: true, CXNS: true } };

options is also forwarded to the MQTT messaging environment's config (e.g. channel, prefix).