'Require is not defined' when adding electron-renderer to webpack - javascript

I am developing an electron app. All good and nice until I wanted to use IPC from the renderer to call some native features. I understand that adding the following line to my Webpack config would allow me to import electron on the renderer side.
module.exports = {
// ...
target: 'electron-renderer',
}
I get the following error when adding this line
Uncaught ReferenceError: require is not defined
And the offending line is
module.exports = require("querystring");
Which sort of makes sense, since the browser does not understand "requires".
Note that without the electron-renderer target the application works well, except I cannot do things like
import {ipcRenderer} from 'electron';
Any thoughts what I could be doing wrong? Thank you!

Just recently ran into this. One thing to look out for is to ensure nodeIntegration is set to true when creating your renderer windows.
mainWindow = new electron.BrowserWindow({
width: width,
height: height,
webPreferences: {
nodeIntegration: true
}
});

Also faced this issue, new answer:
mainWindow = new electron.BrowserWindow({
width: width,
height: height,
webPreferences: {
nodeIntegration: true,
contextIsolation: false
}
});

AFAIU the recommended way is to use contextBridge module (in the preload.js script). It allows you to keep the context isolation enabled but safely expose your APIs to the context the website is running in.
https://www.electronjs.org/docs/latest/tutorial/context-isolation
Following this way, I also found that it was no longer necessary to specify target property in the Webpack config.

Related

How can I run a Python function with JavaScript and HTML? [duplicate]

I am writing an application with the Node.js, Express.js, and Jade combination.
I have file client.js, which is loaded on the client. In that file I have code that calls functions from other JavaScript files. My attempt was to use
var m = require('./messages');
in order to load the contents of messages.js (just like I do on the server side) and later on call functions from that file. However, require is not defined on the client side, and it throws an error of the form Uncaught ReferenceError: require is not defined.
These other JavaScript files are also loaded at runtime at the client, because I place the links at the header of the webpage. So the client knows all the functions that are exported from these other files.
How do I call these functions from these other JavaScript files (such as messages.js) in the main client.js file that opens the socket to the server?
This is because require() does not exist in the browser/client-side JavaScript.
Now you're going to have to make some choices about your client-side JavaScript script management.
You have three options:
Use the <script> tag.
Use a CommonJS implementation. It has synchronous dependencies like Node.js
Use an asynchronous module definition (AMD) implementation.
CommonJS client side-implementations include (most of them require a build step before you deploy):
Browserify - You can use most Node.js modules in the browser. This is my personal favorite.
Webpack - Does everything (bundles JavaScript code, CSS, etc.). It was made popular by the surge of React, but it is notorious for its difficult learning curve.
Rollup - a new contender. It leverages ES6 modules and includes tree-shaking abilities (removes unused code).
You can read more about my comparison of Browserify vs (deprecated) Component.
AMD implementations include:
RequireJS - Very popular amongst client-side JavaScript developers. It is not my taste because of its asynchronous nature.
Note, in your search for choosing which one to go with, you'll read about Bower. Bower is only for package dependencies and is unopinionated on module definitions like CommonJS and AMD.
I am coming from an Electron environment, where I need IPC communication between a renderer process and the main process. The renderer process sits in an HTML file between script tags and generates the same error.
The line
const {ipcRenderer} = require('electron')
throws the Uncaught ReferenceError: require is not defined
I was able to work around that by specifying Node.js integration as true when the browser window (where this HTML file is embedded) was originally created in the main process.
function createAddItemWindow() {
// Create a new window
addItemWindown = new BrowserWindow({
width: 300,
height: 200,
title: 'Add Item',
// The lines below solved the issue
webPreferences: {
nodeIntegration: true,
contextIsolation: false
}
})}
That solved the issue for me. The solution was proposed here.
ES6: In HTML, include the main JavaScript file using attribute type="module" (browser support):
<script type="module" src="script.js"></script>
And in the script.js file, include another file like this:
import { hello } from './module.js';
...
// alert(hello());
Inside the included file (module.js), you must export the function/class that you will import:
export function hello() {
return "Hello World";
}
A working example is here. More information is here.
Replace all require statements with import statements. Example:
// Before:
const Web3 = require('web3');
// After:
import Web3 from 'web3';
It worked for me.
In my case I used another solution.
As the project doesn't require CommonJS and it must have ES3 compatibility (modules not supported) all you need is just remove all export and import statements from your code, because your tsconfig doesn't contain
"module": "commonjs"
But use import and export statements in your referenced files
import { Utils } from "./utils"
export interface Actions {}
Final generated code will always have(at least for TypeScript 3.0) such lines
"use strict";
exports.__esModule = true;
var utils_1 = require("./utils");
....
utils_1.Utils.doSomething();
This worked for me
Get the latest release from the RequireJS download page
It is the file for RequestJS which is what we will use.
Load it into your HTML content like this:
<script data-main="your-script.js" src="require.js"></script>
Notes!
Use require(['moudle-name']) in your-script.js,
not require('moudle-name')
Use const {ipcRenderer} = require(['electron']),
not const {ipcRenderer} = require('electron')
Even using this won't work. I think the best solution is Browserify:
module.exports = {
func1: function () {
console.log("I am function 1");
},
func2: function () {
console.log("I am function 2");
}
};
-getFunc1.js-
var common = require('./common');
common.func1();
window = new BrowserWindow({
webPreferences: {
nodeIntegration: true,
contextIsolation: false
}
});
I confirm. We must add:
webPreferences: {
nodeIntegration: true
}
For example:
mainWindow = new BrowserWindow({webPreferences: {
nodeIntegration: true
}});
For me, the problem has been resolved with that.
People are asking what is the script tag method. Here it is:
<script src='./local.js'></script>.
Or from network:
<script src='https://mycdn.com/myscript.js'></script>
You need plugin the right url for your script.
I was trying to build metronic using webpack. In my package.json I had to remove the "type": "module" section.

Preload scripts not being executed in webview iframes

Webview tag that is present in the renderer process, somewhere in <body>:
<webview src="http://somewebpage.com" preload="somescript.js">
somescript.js is executed in somewebpage, but if somewebpage has <iframe>s in it, the script will not run in the iframe.
How can I make it run? And before any other script in the iframe?
I found this issue on github that seems related:
https://github.com/electron/electron/pull/19260
but it doesn't make any sense...
I tried adding nodeintegrationinsubframes and changing values from false to true
<webview src="somewebpage" preload="somescript.js" nodeintegrationinsubframes="false">
but it has no effect :(
main.js
mainWindow = new BrowserWindow({
width: 1024,
height: 728,
webPreferences: {
nodeIntegrationInSubFrames: true,
webviewTag: true,
nodeIntegration: true
}
});
renderer
<webview
src="https://www.w3schools.com/tags/tryit.asp?filename=tryhtml_iframe"
preload="./preload.js"
style='width: 100%; height: 800px'
nodeIntegrationInSubFrames
/>
preload.js
process.once("loaded", () => {
alert(window.location);
});
You can specify where you are going to execute javascript based on the window.location This above code will show the locations of every sub iframes.
This works for me very well.
I was having the same problems with my project and updating the electron to the latest beta version solved for me.
I assume you know how to do this:
npm install electron#11.0.0-beta.6
You still have to consider the stability concerns of using a development version of the package.
By scratching on electron's documentation perhaps this could be helpful as an alternative.
app.js
let win
app.whenReady().then(() => {
win = new BrowserWindow({
webPreferences: {
nodeIntegrationInSubFrames: true,
webviewTag: true,
nodeIntegration: false,
preload: path.join(app.getAppPath(), 'preload.js') // Specifies a script that will be loaded before other scripts run in the page. This script will always have access to node APIs no matter whether node integration is turned on or off. The value should be the absolute file path to the script. When node integration is turned off, the preload script can reintroduce Node global symbols back to the global scope.
}
})
...
})
renderrer
<webview
src="https://somewebpage.com"
preload="./preload.js"
nodeintegrationinsubframes>
preload.js
/* It can be used by the preload script to add removed Node global symbols back to the global scope when node integration is turned off */
const _setImmediate = setImmediate
const _clearImmediate = clearImmediate
process.once('loaded', () => {
global.setImmediate = _setImmediate
global.clearImmediate = _clearImmediate
})
My answer is based on the following resources:
Electron Documentation: Tag
Electron Documentation:
BrowserWindow
Electron Documentation: process
Electron
Documentation: Web embeds in Electron - WebViews
Electron
Documentation: Preload Example

Error with javascript: require('fs'). Why? [duplicate]

I am writing an application with the Node.js, Express.js, and Jade combination.
I have file client.js, which is loaded on the client. In that file I have code that calls functions from other JavaScript files. My attempt was to use
var m = require('./messages');
in order to load the contents of messages.js (just like I do on the server side) and later on call functions from that file. However, require is not defined on the client side, and it throws an error of the form Uncaught ReferenceError: require is not defined.
These other JavaScript files are also loaded at runtime at the client, because I place the links at the header of the webpage. So the client knows all the functions that are exported from these other files.
How do I call these functions from these other JavaScript files (such as messages.js) in the main client.js file that opens the socket to the server?
This is because require() does not exist in the browser/client-side JavaScript.
Now you're going to have to make some choices about your client-side JavaScript script management.
You have three options:
Use the <script> tag.
Use a CommonJS implementation. It has synchronous dependencies like Node.js
Use an asynchronous module definition (AMD) implementation.
CommonJS client side-implementations include (most of them require a build step before you deploy):
Browserify - You can use most Node.js modules in the browser. This is my personal favorite.
Webpack - Does everything (bundles JavaScript code, CSS, etc.). It was made popular by the surge of React, but it is notorious for its difficult learning curve.
Rollup - a new contender. It leverages ES6 modules and includes tree-shaking abilities (removes unused code).
You can read more about my comparison of Browserify vs (deprecated) Component.
AMD implementations include:
RequireJS - Very popular amongst client-side JavaScript developers. It is not my taste because of its asynchronous nature.
Note, in your search for choosing which one to go with, you'll read about Bower. Bower is only for package dependencies and is unopinionated on module definitions like CommonJS and AMD.
I am coming from an Electron environment, where I need IPC communication between a renderer process and the main process. The renderer process sits in an HTML file between script tags and generates the same error.
The line
const {ipcRenderer} = require('electron')
throws the Uncaught ReferenceError: require is not defined
I was able to work around that by specifying Node.js integration as true when the browser window (where this HTML file is embedded) was originally created in the main process.
function createAddItemWindow() {
// Create a new window
addItemWindown = new BrowserWindow({
width: 300,
height: 200,
title: 'Add Item',
// The lines below solved the issue
webPreferences: {
nodeIntegration: true,
contextIsolation: false
}
})}
That solved the issue for me. The solution was proposed here.
ES6: In HTML, include the main JavaScript file using attribute type="module" (browser support):
<script type="module" src="script.js"></script>
And in the script.js file, include another file like this:
import { hello } from './module.js';
...
// alert(hello());
Inside the included file (module.js), you must export the function/class that you will import:
export function hello() {
return "Hello World";
}
A working example is here. More information is here.
Replace all require statements with import statements. Example:
// Before:
const Web3 = require('web3');
// After:
import Web3 from 'web3';
It worked for me.
In my case I used another solution.
As the project doesn't require CommonJS and it must have ES3 compatibility (modules not supported) all you need is just remove all export and import statements from your code, because your tsconfig doesn't contain
"module": "commonjs"
But use import and export statements in your referenced files
import { Utils } from "./utils"
export interface Actions {}
Final generated code will always have(at least for TypeScript 3.0) such lines
"use strict";
exports.__esModule = true;
var utils_1 = require("./utils");
....
utils_1.Utils.doSomething();
This worked for me
Get the latest release from the RequireJS download page
It is the file for RequestJS which is what we will use.
Load it into your HTML content like this:
<script data-main="your-script.js" src="require.js"></script>
Notes!
Use require(['moudle-name']) in your-script.js,
not require('moudle-name')
Use const {ipcRenderer} = require(['electron']),
not const {ipcRenderer} = require('electron')
Even using this won't work. I think the best solution is Browserify:
module.exports = {
func1: function () {
console.log("I am function 1");
},
func2: function () {
console.log("I am function 2");
}
};
-getFunc1.js-
var common = require('./common');
common.func1();
window = new BrowserWindow({
webPreferences: {
nodeIntegration: true,
contextIsolation: false
}
});
I confirm. We must add:
webPreferences: {
nodeIntegration: true
}
For example:
mainWindow = new BrowserWindow({webPreferences: {
nodeIntegration: true
}});
For me, the problem has been resolved with that.
People are asking what is the script tag method. Here it is:
<script src='./local.js'></script>.
Or from network:
<script src='https://mycdn.com/myscript.js'></script>
You need plugin the right url for your script.
I was trying to build metronic using webpack. In my package.json I had to remove the "type": "module" section.

TypeError: window.require is not a function

Im trying to build an electron app and want to use window.require. Unfortunately the compiler says "TypeError: window.require is not a function". Ironically require works only in main.js.
Here the code Im trying to run:
const electron = window.require('electron')
const low = window.require('lowdb')
const FileSync = window.require('lowdb/adapters/FileSync')
I read in another post that somebody have had the same problem and it was fixed by adding this code into the .html file:
<script type="text/javascript" src="../../../Gehaltseinstellungen_Hinzufügen.js">
window.nodeRequire = require;
delete window.require;
delete window.exports;
delete window.module;
</script>
Also the author said using "nodeRequire" instead of require would solve the problem but it doesn't...
Another option I read about is that the NodeIntegration is set to false while the rendering process is activated, but I don't know how to activate Node while rendering.
you can set the webPreferences.contextIsolation to be false like this
webPreferences: {
nodeIntegration: true,
contextIsolation: false
}
it maybe works
It is unclear what version of Electron you are using. The syntax you are using is non-standard.
First – if you are using Electron 5.0, nodeIntegration is false by default in BrowserWindows so you need to specify it explicitly when you create your window:
mainWindow = new BrowserWindow({
width: 800,
height: 600,
webPreferences: {
nodeIntegration: true
}
})
Given the above, the syntax below works fine (i.e. no 'window' reference needed):
const { ipcRenderer, remote } = require('electron');
Needed all 3 setup like so to make this work:
webPreferences: {
nodeIntegration: true,
enableRemoteModule: true,
contextIsolation: false,
},
note: macbook m1, big sur 11.4, maybe it has to do something about OS, idk.
P.s. As mentioned in comments, before using nodeIntegration - check the Electron docs to understand when it may be a security issue:
Isolation For Untrusted Content A security issue exists whenever you
receive code from an untrusted source (e.g. a remote server) and
execute it locally. As an example, consider a remote website being
displayed inside a default BrowserWindow. If an attacker somehow
manages to change said content (either by attacking the source
directly, or by sitting between your app and the actual destination),
they will be able to execute native code on the user's machine.
⚠️ Under no circumstances should you load and execute remote code with
Node.js integration enabled. Instead, use only local files (packaged
together with your application) to execute Node.js code. To display
remote content, use the tag or BrowserView, make sure to
disable the nodeIntegration and enable contextIsolation.
Source: https://www.electronjs.org/docs/latest/tutorial/security#isolation-for-untrusted-content
I also met this issue in Electron + Angular.
webPreferences: {
nodeIntegration: true,
contextIsolation: false
}
Configuration above works for me.
Same issue in Electron + React + Typescript. This solved it for me
webPreferences: {
nodeIntegration: true,
enableRemoteModule: true,
contextIsolation: false
}
I was stuck with this problem for a couple of days.
Could not figure out for the life of me.
Went through a lot of docs and stackoverflow and finally!!!!
I fixed this error the following way :
create a file preload.js :
const { remote } = require('electron');
window.ipcRenderer = require('electron').ipcRenderer;
then in main.js/electron.js:
const win = new BrowserWindow({
width: 800,
height: 600,
webPreferences: {
nodeIntegration: true,
//this line is crucial
preload: path.join(app.getAppPath(), '/path-to-file/preload.js'),
contextIsolation: false
}
})
and finally in App.js:
const { ipcRenderer } = window
I got ipcRenderer in window from electron.
I'm pretty sure you can get anything else that you would want.
You don't need to modify web preferences as has been suggested, and I would recommend not doing it unless you have a better reason to because of the implied security issues (https://www.electronjs.org/docs/latest/tutorial/security#isolation-for-untrusted-content).
Instead, what you can do is use the preload script to add any functionality you need to window. Like this for example:
preload.js (located in the root folder):
contextBridge.exposeInMainWorld('ipcRenderer', {
invoke: (event) => ipcRenderer.invoke(event),
});
webPreferences in main.js:
webPreferences: {
preload: path.join(__dirname, 'preload.js'),
}
Now in your code you can reference it:
const { ipcRenderer } = window as any;
const response = await ipcRenderer.invoke(...);
Reference documentation here: https://www.electronjs.org/docs/latest/tutorial/tutorial-preload#communicating-between-processes

Client on Node.js: Uncaught ReferenceError: require is not defined

I am writing an application with the Node.js, Express.js, and Jade combination.
I have file client.js, which is loaded on the client. In that file I have code that calls functions from other JavaScript files. My attempt was to use
var m = require('./messages');
in order to load the contents of messages.js (just like I do on the server side) and later on call functions from that file. However, require is not defined on the client side, and it throws an error of the form Uncaught ReferenceError: require is not defined.
These other JavaScript files are also loaded at runtime at the client, because I place the links at the header of the webpage. So the client knows all the functions that are exported from these other files.
How do I call these functions from these other JavaScript files (such as messages.js) in the main client.js file that opens the socket to the server?
This is because require() does not exist in the browser/client-side JavaScript.
Now you're going to have to make some choices about your client-side JavaScript script management.
You have three options:
Use the <script> tag.
Use a CommonJS implementation. It has synchronous dependencies like Node.js
Use an asynchronous module definition (AMD) implementation.
CommonJS client side-implementations include (most of them require a build step before you deploy):
Browserify - You can use most Node.js modules in the browser. This is my personal favorite.
Webpack - Does everything (bundles JavaScript code, CSS, etc.). It was made popular by the surge of React, but it is notorious for its difficult learning curve.
Rollup - a new contender. It leverages ES6 modules and includes tree-shaking abilities (removes unused code).
You can read more about my comparison of Browserify vs (deprecated) Component.
AMD implementations include:
RequireJS - Very popular amongst client-side JavaScript developers. It is not my taste because of its asynchronous nature.
Note, in your search for choosing which one to go with, you'll read about Bower. Bower is only for package dependencies and is unopinionated on module definitions like CommonJS and AMD.
I am coming from an Electron environment, where I need IPC communication between a renderer process and the main process. The renderer process sits in an HTML file between script tags and generates the same error.
The line
const {ipcRenderer} = require('electron')
throws the Uncaught ReferenceError: require is not defined
I was able to work around that by specifying Node.js integration as true when the browser window (where this HTML file is embedded) was originally created in the main process.
function createAddItemWindow() {
// Create a new window
addItemWindown = new BrowserWindow({
width: 300,
height: 200,
title: 'Add Item',
// The lines below solved the issue
webPreferences: {
nodeIntegration: true,
contextIsolation: false
}
})}
That solved the issue for me. The solution was proposed here.
ES6: In HTML, include the main JavaScript file using attribute type="module" (browser support):
<script type="module" src="script.js"></script>
And in the script.js file, include another file like this:
import { hello } from './module.js';
...
// alert(hello());
Inside the included file (module.js), you must export the function/class that you will import:
export function hello() {
return "Hello World";
}
A working example is here. More information is here.
Replace all require statements with import statements. Example:
// Before:
const Web3 = require('web3');
// After:
import Web3 from 'web3';
It worked for me.
In my case I used another solution.
As the project doesn't require CommonJS and it must have ES3 compatibility (modules not supported) all you need is just remove all export and import statements from your code, because your tsconfig doesn't contain
"module": "commonjs"
But use import and export statements in your referenced files
import { Utils } from "./utils"
export interface Actions {}
Final generated code will always have(at least for TypeScript 3.0) such lines
"use strict";
exports.__esModule = true;
var utils_1 = require("./utils");
....
utils_1.Utils.doSomething();
This worked for me
Get the latest release from the RequireJS download page
It is the file for RequestJS which is what we will use.
Load it into your HTML content like this:
<script data-main="your-script.js" src="require.js"></script>
Notes!
Use require(['moudle-name']) in your-script.js,
not require('moudle-name')
Use const {ipcRenderer} = require(['electron']),
not const {ipcRenderer} = require('electron')
Even using this won't work. I think the best solution is Browserify:
module.exports = {
func1: function () {
console.log("I am function 1");
},
func2: function () {
console.log("I am function 2");
}
};
-getFunc1.js-
var common = require('./common');
common.func1();
window = new BrowserWindow({
webPreferences: {
nodeIntegration: true,
contextIsolation: false
}
});
I confirm. We must add:
webPreferences: {
nodeIntegration: true
}
For example:
mainWindow = new BrowserWindow({webPreferences: {
nodeIntegration: true
}});
For me, the problem has been resolved with that.
People are asking what is the script tag method. Here it is:
<script src='./local.js'></script>.
Or from network:
<script src='https://mycdn.com/myscript.js'></script>
You need plugin the right url for your script.
I was trying to build metronic using webpack. In my package.json I had to remove the "type": "module" section.

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