How to prevent multiple instances in Electron
I do not know if this is possible but I might as well give it a chance and ask. I'm doing an Electron app and I'd like to know if it is possible to have no more than a single instance at a time.
I have found this gist but I'm not sure hot to use it. Can someone shed some light of share a better idea ?
var preventMultipleInstances = function(window) {
var socket = (process.platform === 'win32') ? '\\\\.\\pipe\\myapp-sock' : path.join(os.tmpdir(), 'myapp.sock');
net.connect({path: socket}, function () {
var errorMessage = 'Another instance of ' + pjson.productName + ' is already running. Only one instance of the app can be open at a time.'
dialog.showMessageBox(window, {'type': 'error', message: errorMessage, buttons: ['OK']}, function() {
window.destroy()
})
}).on('error', function (err) {
if (process.platform !== 'win32') {
// try to unlink older socket if it exists, if it doesn't,
// ignore ENOENT errors
try {
fs.unlinkSync(socket);
} catch (e) {
if (e.code !== 'ENOENT') {
throw e;
}
}
}
net.createServer(function (connection) {}).listen(socket);;
});
}
Solution 1:
There is a new API now: requestSingleInstanceLock
const { app } = require('electron')
let myWindow = null
const gotTheLock = app.requestSingleInstanceLock()
if (!gotTheLock) {
app.quit()
} else {
app.on('second-instance', (event, commandLine, workingDirectory) => {
// Someone tried to run a second instance, we should focus our window.
if (myWindow) {
if (myWindow.isMinimized()) myWindow.restore()
myWindow.focus()
}
})
// Create myWindow, load the rest of the app, etc...
app.on('ready', () => {
})
}
Solution 2:
Use the makeSingleInstance
function in the app
module, there's even an example in the docs.
Solution 3:
In Case you need the code.
let mainWindow = null;
//to make singleton instance
const isSecondInstance = app.makeSingleInstance((commandLine, workingDirectory) => {
// Someone tried to run a second instance, we should focus our window.
if (mainWindow) {
if (mainWindow.isMinimized()) mainWindow.restore()
mainWindow.focus()
}
})
if (isSecondInstance) {
app.quit()
}