javascript - Creating invisible window from main process to compute function in Electron -


i trying write electron program in main process creates invisible window, sends number window, window computes factorial , sends back.

this in main process:

function invisiblewindow() {   const invispath = 'file://' + path.join(__dirname, 'files/html/inv.html')    let win = new browserwindow({ width: 400, height: 400, show: false })   win.loadurl(invispath)    win.webcontents.on('did-finish-load', function () {     const input = 100;     win.webcontents.send('compute-factorial', input);   })      ipcmain.on('factorial-computed', function (event, input, output) {     const message = `the factorial of ${input} ${output}`     console.log(message);   }) }

the function gets called in main process by:

app.on('ready', () => {   // creates different window here    invisiblewindow(); });

this inv.html file:

<html>   <script type="text/javascript">     const ipc = require('electron').ipcrenderer     const browserwindow = require('electron').remote.browserwindow      ipc.on('compute-factorial', function (event, number) {       const result = factorial(number)        ipcrenderer.send('factorial-computed', number, result)       window.close()     })      function factorial (num) {       if (num === 0) return 1       return num * factorial(num - 1)     }   </script> </html>

now after have added program, every time when start through terminal, not terminate when other (visible) windows closed. guess because invisible window still opened because did not receive compute-factorial event.

what doing wrong?

this because of race condition. electron docs:

event: 'did-finish-load'

emitted when navigation done, i.e. spinner of tab has stopped spinning, , onload event dispatched.

you can try settimeout:

win.webcontents.on('did-finish-load', function () {   settimeout(() => {     const input = 100;     win.webcontents.send('compute-factorial', input);   }, 3000); });

the main process not know when dom ready. can this.

send main process "dom-is-ready" event.

inv.html

ipc.send('dom-is-ready');

paste 'did-finish-load' code 'dom-is-ready'.

main.js

function invisiblewindow() {   const invispath = 'file://' + path.join(__dirname, 'files/html/inv.html');    const win = new browserwindow({      width: 400,      height: 400,      show: false    });    win.loadurl(invispath);    win.webcontents.on('did-finish-load', function () {     win.show();   });    ipcmain.on('dom-is-ready', function (event) {     const input = 100;     win.webcontents.send('compute-factorial', input);   });    ipcmain.on('factorial-computed', function (event, input, output) {     const message = `the factorial of ${input} ${output}`     console.log(message);   }); }

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