Nodejs/electron Override chromium browser timeout. - node.js

Been looking all over for this information, closest i can see is the
command line switches. i have a web page that i ported to electron and im trying to override the Browser inactivity timeout. for example running a report over 2 minutes the browser times out the connection. My thinking for a quick fix was to wrap in electron and extend the browser timeout.
https://peter.sh/experiments/chromium-command-line-switches/#timeout
https://github.com/electron/electron/blob/master/docs/api/chrome-command-line-switches.md
In Electron the main.js looks to have wrapped the modules in webpack
in all of the examples ive found
it looks like this
You can use app.commandLine.appendSwitch to append them in your app's main script before the ready event of the app module is emitted:
const { app } = require('electron')
app.commandLine.appendSwitch('remote-debugging-port', '8315')
app.commandLine.appendSwitch('host-rules', 'MAP * 127.0.0.1')
app.on('ready', () => {
// Your code here
})
however in my electron file my const app is actually
const path = __webpack_require__(14);
const electron = __webpack_require__(18);
const unusedFilename = __webpack_require__(20);
const pupa = __webpack_require__(23);
const extName = __webpack_require__(24);
const {app, shell} = electron;
i have tried
app.commandLine.appendSwitch("--disable-renderer-backgrounding");
app.commandLine.appendArgument('--disable-timeouts-for-profiling');
Doesnt seem to work, Any hints would be appreciated.

Related

how to solve this error indexhtml :Uncaught ReferenceError: require is not defined in electron [duplicate]

This question already has answers here:
With contextIsolation = true, is it possible to use ipcRenderer?
(3 answers)
Closed 1 year ago.
> index.html:
As u can see in index.html code (const electron = require('electron');this require arise an error as require is not define i use window10.
<script>
const electron = require('electron');
const { ipcRenderer } = electron;
document.querySelector('form').addEventListener('submit',(event) =>{event.preventDefault();
event.preventDefault();
const file =document.querySelector('input').files[0];
});
</script>
> Main.js:
// Modules to control application life and create native browser window
const {app, BrowserWindow} = require('electron')
const path = require('path')
function createWindow () {
// Create the browser window.
const mainWindow = new BrowserWindow({
width: 800,
height: 600,
webPreferences: {
nodeIntegration: true, // is default value after Electron v5
contextIsolation: true, // protect against prototype pollution
enableRemoteModule: false, // turn off remote
preload: path.join(__dirname, "preload.js") // use a preload script
}
});
mainWindow.loadFile('index.html')
Electron is a package you should use in the nodejs environment, not in the browser. Also in the browser you can't use the require function, you should use instead the import and export syntax.
That because javascript is a script language meant to run in browsers, it doesn't make sense to require electron in your frontend script, but, since your serving your files through the electron service and not in a browser window you can access the require by calling the window.require('pckg') method, still doesn't make any sense to require electron in a client-side window tho, it's like if an express server renders a page that creates another server.
If you just want to create another window you should do that in the main electron file, in your case the Main.js file.

White Screen issue with Electron/Node app

I've recently created an app with a Java backend and a React frontend, and I was using Electron and some Node features to bundle the app and create a desktop app for it. Basically, I decided to use Java for some Java-specific libraries I needed. The app will run on port 8080, with the React/JS stuff being served from the static folder, and the Electron wrapper will use some Node libraries to start up the Java process and then after a few seconds connect to localhost:8080.
This works like a charm about half the time, and the other half instead shows me a white screen with no errors! I have debugged this countless times and the only way to fix it is to force reload the Chromium page which sometimes works, and other times doesn't. Obviously this isn't acceptable for users to do with my app. The problem is, I have run out of ideas as to what could be causing this issue.
Here is my main.js for the electron app
const {app, BrowserWindow} = require('electron')
function createWindow () {
try {
var jarPath = './app.jar';
var kill = require('tree-kill');
var child = require('child_process').spawn('java', ['-jar', jarPath, '']);
let win = new BrowserWindow({width: 1000, height: 730});
setTimeout(function() {
win.loadURL('http://localhost:8080/index.html');
}, 2000);
console.log("PID: " + child.pid);
win.on('closed', function () {
kill(child.pid);
mainWindow = null
}
)
} catch(e) {
console.log(e);
}
}
app.on('ready', createWindow)

Electron - "Cannot read property 'on' of undefined"; tried reinstalling,

I'm testing an electron app but I'm getting this pernicious error:
"TypeError: Cannot read property 'on' of undefined"
The research I've done pointed to either a botched module install, a syntax issue, or passing in an undefined variable to the app.on, and I suspect the issue may be Electron being pointed to incorrectly (now it's being pointed to the folder ending in electron\dist\electron.exe, which I've heard might not the right location), but I'm unsure.
Despite checking the require command, syntax, rechecking, uninstalling, and reinstalling node, I can't seem to make this darn error go away. What could be causing this?
const electron = require('electron');
const os = require('os');
const fs = require('fs');
const app = electron.app;
const BrowserWindow = electron.BrowserWindow;
var Mousetrap = require('mousetrap');
const path = require('path');
const url = require('url');
const ipc = electron.ipcMain;
let mainWindow;
function createWindow () {
// Create the browser window.
mainWindow = new BrowserWindow({width: 800, height: 600})
// and load the index.html of the app.
mainWindow.loadURL(url.format({
pathname: path.join(__dirname, 'index.html'),
protocol: 'file:',
slashes: true
/* More code in this and sub functions*/
}))
}
})
const preferencesManager = require('./preferencesManager');
/******
Send data to database given constructor created in preferencesManager
******/
// First instantiate the class because we want to turn the class into an object to be able to use.
const store = new Store({ //create a new getting and setting logic
//We'll call our data file 'user-preferences'
configName: 'user-preferences',
defaults: {
//800 x 600 is the default size of our window
windowBounds: { width: 800, height: 600}
}
});
// When our app is ready, we'll create our BrowserWindow
app.on('ready',function(){
//Set up a listener for what I've done in keycapture (in the renderer process)
//???
ipc.on('invokeAction', function(event, args){
/* Do some action */
});
});
You are probably trying to run your application like a node app with:
$ node index.js
The electron file is a binary file, not a JavaScript file, when you require it an run with node there will be no object to call electron.app, so it parses for null and cannot have an property. As in the getting started documento of Electron.JS you must run the application like this:
Change your package.json script session adding start:
{
"scripts": {
"start": "electron ."
}
}
Now run:
$ npm start
The code you posted has an error, witch may be an edition error while coping and pasting but it should loose some parenthesis and curly brackets:
function createWindow () {
// Create the browser window.
mainWindow = new BrowserWindow({width: 800, height: 600})
// and load the index.html of the app.
mainWindow.loadURL(url.format({
pathname: path.join(__dirname, 'index.html'),
protocol: 'file:',
slashes: true
/* More code in this and sub functions*/
}))
}
The application should now run correctly. I tested you exact code, removing the libs I did not have and it loaded with no errors.

How to use filesystem (fs) in angular-cli with electron-js

I have set up an angular-cli project
(# Angular / cli: 1.0.0-rc.2 node: 6.10.0 os: linux x64)
With electron js (v1.6.2)
And I need to use the filesystem to create / delete .csv files and folders, but I can not do includ in the angular component
How could you configure the angular-cli to be able to: import fs from 'fs'?
You wouldn't configure Angular-CLI to use the NodeJS fs module.
In electron you have 2 processes; main and renderer. The main process controls items such as the browserWindow, which is essentially the 'window' the user sees when they open their app, and in turn this loads the html file for the view. Here, in the main process, you import the fs module.
In the render process, you would handle actions from the view, and send them to the main process. This is where you would use IPC to communicate via events to do something with the main process. Once that event is triggered, the render process takes the event and sends it to main. Main would do something with it, and open a file for example on the desktop.
I would recommend using the electron API demo application to see clear examples of this. Here is an example of print to pdf using FS (from the demo app).
Also, here is an electron application github example written by Ray Villalobos using React, which has some similar concepts that will show you how to integrate components in your app.
Render process:
const ipc = require('electron').ipcRenderer
const printPDFBtn = document.getElementById('print-pdf')
printPDFBtn.addEventListener('click', function (event) {
ipc.send('print-to-pdf')
})
ipc.on('wrote-pdf', function (event, path) {
const message = `Wrote PDF to: ${path}`
document.getElementById('pdf-path').innerHTML = message
})
Main Process:
const fs = require('fs')
const os = require('os')
const path = require('path')
const electron = require('electron')
const BrowserWindow = electron.BrowserWindow
const ipc = electron.ipcMain
const shell = electron.shell
ipc.on('print-to-pdf', function (event) {
const pdfPath = path.join(os.tmpdir(), 'print.pdf')
const win = BrowserWindow.fromWebContents(event.sender)
// Use default printing options
win.webContents.printToPDF({}, function (error, data) {
if (error) throw error
fs.writeFile(pdfPath, data, function (error) {
if (error) {
throw error
}
shell.openExternal('file://' + pdfPath)
event.sender.send('wrote-pdf', pdfPath)
})
})
})
You can try using const fs = (<any>window).require("fs"); within the component or better still, create a service.ts provider to handle i/o operations.

How to integrate and run existing ReactJS Application in Electron

For instance, I have an ReactJS application: https://iaya-664f3.firebaseapp.com/
You can see in the HTML source the bundle.js file.
I have tried to run this application as desktop application using Electron, which should launch this web application in chromium window but it is not working.
Following is my main React application file app.js sitting in root directory. However compiled files bundle.js and index.html are in ./public/directory.
./app.js
import React, {Component} from 'react';
import ReactDOM from 'react-dom';
import { Router, Route, browserHistory } from 'react-router';
import routes from './routes';
import {Provider} from "react-redux";
import { createStore, applyMiddleware } from 'redux';
import ReduxPromise from 'redux-promise';
import rootReducer from './reducers/index';
const store = applyMiddleware(ReduxPromise)(createStore)(rootReducer);
ReactDOM.render( <Provider store={store}>
<Router history={browserHistory} routes={routes} />
</Provider> ,
document.getElementById('react-app'));
./index.js
In this file I'm embedding my application to Electron to run in chromium.
var app = require("./app");
var BrowserWindow = require("browser-window");
// on electron has started up , booted up, everything loaded (Chromium ,goen, live)
app.on("ready", function(){
var mainWindow = new BrowserWindow({
width:800,
height:600
});
mainWindow.loadUrl("file://" + __dirname+ "/public/index.html");
});
But this give some error on import React from 'React' line in my ./app.js.
So I assume that, I should only give ./public/index.html file to load which includes the compiled bundle.js. But I wonder, how that will work as the line app.on("ready", function(){ expect an app.
Moreover I have also tried following way in ./index.js but it gives some other error.
const electron = require('electron');
// Module to control application life.
const app = electron.app;
// Module to create native browser window.
const BrowserWindow = electron.BrowserWindow;
const path = require('path');
const url = require('url');
// Keep a global reference of the window object, if you don't, the window will
// be closed automatically when the JavaScript object is garbage collected.
let mainWindow;
function createWindow () {
// Create the browser window.
mainWindow = new BrowserWindow({width: 800, height: 600});
// and load the index.html of the app.
/*mainWindow.loadURL(url.format({
pathname: path.join(__dirname, 'public/index.html'),
protocol: 'file:',
slashes: true
}));*/
mainWindow.loadURL("file://" + __dirname+ "/public/index.html");
// Open the DevTools.
mainWindow.webContents.openDevTools();
// Emitted when the window is closed.
mainWindow.on('closed', function () {
// Dereference the window object, usually you would store windows
// in an array if your app supports multi windows, this is the time
// when you should delete the corresponding element.
mainWindow = null;
});
}
app.on('ready', createWindow);
// Quit when all windows are closed.
app.on('window-all-closed', function () {
// On OS X it is common for applications and their menu bar
// to stay active until the user quits explicitly with Cmd + Q
if (process.platform !== 'darwin') {
app.quit();
}
});
app.on('activate', function () {
// On OS X it's common to re-create a window in the app when the
// dock icon is clicked and there are no other windows open.
if (mainWindow === null) {
createWindow();
}
});
Basically the thing is very simple. Electron acts just like a desktop chromium wrapper, that displays your any (any) type of web page inside desktop chromium.
So for example, we want to display http://www.google.com then you simply pass this URL to your loadURL() function.
Here is the working copy of code (asked in the question):
const electron = require('electron');
// Module to control application life.
const app = electron.app;
// Module to create native browser window.
const BrowserWindow = electron.BrowserWindow;
app.on('ready', function(){
var mainWindow = new BrowserWindow({width: 800, height: 600});
mainWindow.loadURL("http://localhost:8080/"); // option1: (loading a local app running on a local server)
//mainWindow.loadURL("https://iaya-664f3.firebaseapp.com"); // option2: (loading external hosted app)
// loading developer tool for debugging
mainWindow.webContents.openDevTools();
});
I hope this will clarify the confusion for many people, who are new to Electron. So the final words are that Electron only loads existing and running web application. It does not compile, does not act as a server. It is just a box in which you can put anything and give it a desktop sort of look e.g. menues, desktop notification, local file system access, etc.

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