---
title: Electron
pagination_prev: demos/mobile/index
pagination_next: demos/cli/index
sidebar_position: 1
sidebar_custom_props:
summary: Embedded NodeJS + Chromium
---
import Tabs from '@theme/Tabs';
import TabItem from '@theme/TabItem';
The [NodeJS Module](/docs/getting-started/installation/nodejs) can be imported
from the main or the renderer thread.
The "Complete Example" creates an app that looks like the screenshots below:
## Integration Details
Electron presents a `fs` module. The `require('xlsx')` call loads the CommonJS
module, so `XLSX.readFile` and `XLSX.writeFile` work in the renderer thread.
### Reading Files
Electron offers 3 different ways to read files, two of which use Web APIs.
**File Input Element**
File input elements automatically map to standard Web APIs.
For example, assuming a file input element on the page:
```html
```
The event handler would process the event as if it were a web event:
```js
async function handleFile(e) {
const file = e.target.files[0];
const data = await file.arrayBuffer();
/* data is an ArrayBuffer */
const workbook = XLSX.read(data);
/* DO SOMETHING WITH workbook HERE */
}
document.getElementById("xlf").addEventListener("change", handleFile, false);
```
**Drag and Drop**
The [drag and drop snippet](/docs/solutions/input#example-user-submissions)
applies to DIV elements on the page.
For example, assuming a DIV on the page:
```html
Drop a spreadsheet file here to see sheet data
```
The event handler would process the event as if it were a web event:
```js
async function handleDrop(e) {
e.stopPropagation();
e.preventDefault();
const file = e.dataTransfer.files[0];
const data = await file.arrayBuffer();
/* data is an ArrayBuffer */
const workbook = XLSX.read(data);
/* DO SOMETHING WITH workbook HERE */
}
document.getElementById("drop").addEventListener("drop", handleDrop, false);
```
**Electron API**
[`XLSX.readFile`](/docs/api/parse-options) reads workbooks from the file system.
`showOpenDialog` shows a Save As dialog and returns the selected file name.
Unlike the Web APIs, the `showOpenDialog` flow can be initiated by app code:
```js
/* from the renderer thread */
const electron = require('@electron/remote');
/* this function will show the open dialog and try to parse the workbook */
async function importFile() {
/* show Save As dialog */
const result = await electron.dialog.showOpenDialog({
title: 'Select a file',
filters: [{
name: "Spreadsheets",
extensions: ["xlsx", "xls", "xlsb", /* ... other formats ... */]
}]
});
/* result.filePaths is an array of selected files */
if(result.filePaths.length == 0) throw new Error("No file was selected!");
// highlight-next-line
return XLSX.readFile(result.filePaths[0]);
}
```
:::note pass
`showOpenDialog` originally returned an array of paths:
```js
var dialog = require('electron').remote.dialog;
function importFile(workbook) {
var result = dialog.showOpenDialog({ properties: ['openFile'] });
return XLSX.readFile(result[0]);
}
```
This method was renamed to `showOpenDialogSync` in Electron 6.
:::
### Writing Files
[`XLSX.writeFile`](/docs/api/write-options) writes workbooks to the file system.
`showSaveDialog` shows a Save As dialog and returns the selected file name:
```js
/* from the renderer thread */
const electron = require('@electron/remote');
/* this function will show the save dialog and try to write the workbook */
async function exportFile(workbook) {
/* show Save As dialog */
const result = await electron.dialog.showSaveDialog({
title: 'Save file as',
filters: [{
name: "Spreadsheets",
extensions: ["xlsx", "xls", "xlsb", /* ... other formats ... */]
}]
});
/* write file */
// highlight-next-line
XLSX.writeFile(workbook, result.filePath);
}
```
:::note pass
`showSaveDialog` originally returned the selected path:
```js
var dialog = require('electron').remote.dialog;
function exportFile(workbook) {
var result = dialog.showSaveDialog();
XLSX.writeFile(workbook, result);
}
```
This method was renamed to `showSaveDialogSync` in Electron 6.
:::
## Complete Example
:::note Tested Deployments
This demo was tested in the following environments:
| OS and Version | Architecture | Electron | Date |
|:---------------|:-------------|:---------|:-----------|
| macOS 14.4 | `darwin-x64` | `29.1.4` | 2024-03-15 |
| macOS 14.1.2 | `darwin-arm` | `27.1.3` | 2023-12-01 |
| Windows 10 | `win10-x64` | `28.2.0` | 2024-03-04 |
| Windows 11 | `win11-arm` | `27.1.3` | 2023-12-01 |
| Linux (HoloOS) | `linux-x64` | `29.1.4` | 2024-03-21 |
| Linux (Debian) | `linux-arm` | `27.1.3` | 2023-12-01 |
:::
This demo includes a drag-and-drop box as well as a file input box, mirroring
the [SheetJS Data Preview Live Demo](https://oss.sheetjs.com/sheetjs/)
The core data in this demo is an editable HTML table. The readers build up the
table using `sheet_to_html` (with `editable:true` option) and the writers scrape
the table using `table_to_book`.
The demo project is wired for `electron-forge` to build the standalone binary.
1) Download the demo files:
- [`package.json`](pathname:///electron/package.json) : project structure
- [`main.js`](pathname:///electron/main.js) : main process script
- [`index.html`](pathname:///electron/index.html) : window page
- [`index.js`](pathname:///electron/index.js) : script loaded in render context
:::caution pass
Right-click each link and select "Save Link As...". Left-clicking a link will
try to load the page in your browser. The goal is to save the file contents.
:::
These instructions can be run in a Terminal (bash) or Command Prompt window:
```bash
mkdir sheetjs-electron
cd sheetjs-electron
curl -LO https://docs.sheetjs.com/electron/package.json
curl -LO https://docs.sheetjs.com/electron/main.js
curl -LO https://docs.sheetjs.com/electron/index.html
curl -LO https://docs.sheetjs.com/electron/index.js
```
2) Install dependencies:
```bash
npm install
```
3) To verify the app works, run in the test environment:
```bash
npx -y electron .
```
The app will show.
4) To build a standalone app, run the builder:
```bash
npm run make
```
This will create a package in the `out\make` folder and a standalone binary.
:::caution pass
On Linux, the packaging step may require additional dependencies[^1]
:::
:::info pass
When the demo was last tested on Windows ARM, the generated binary targeted x64.
The program will run on ARM64 Windows.
:::
### Testing
5) Download [the test file `pres.numbers`](https://docs.sheetjs.com/pres.numbers)
6) Launch the generated application:
| Architecture | Command |
|:-------------|:--------------------------------------------------------------|
| `darwin-x64` | `open ./out/sheetjs-electron-darwin-x64/sheetjs-electron.app` |
| `win10-x64` | `.\out\sheetjs-electron-win32-x64\sheetjs-electron.exe` |
| `linux-x64` | `./out/sheetjs-electron-linux-x64/sheetjs-electron` |
#### Electron API
7) Click "Click here to select a file from your computer". With the file picker,
navigate to the Downloads folder and select `pres.numbers`.
The application should show data in a table.
8) Click "Export Data!" and click "Save" in the popup. By default, it will try
to write to `Untitled.xls` in the Downloads folder.
:::note pass
In some tests, the dialog did not have a default name.
If there is no default name, enter `Untitled.xls` and click "Save".
:::
The app will show a popup once the data is exported. Open the file in a
spreadsheet editor and compare the data to the table shown in the application.
#### Drag and Drop
9) Close the application, end the terminal process and re-launch (see step 6)
10) Open the Downloads folder in a file explorer or finder window.
11) Click and drag the `pres.numbers` file from the Downloads folder to the
bordered "Drop a spreadsheet file" box. The file data should be displayed.
#### File Input Element
12) Close the application, end the terminal process and re-launch (see step 6)
13) Click "Choose File". With the file picker, navigate to the Downloads folder
and select `pres.numbers`.
## Electron Breaking Changes
The first version of this demo used Electron 1.7.5. The current demo includes
the required changes for Electron 28.2.0.
There are no Electron-specific workarounds in the library, but Electron broke
backwards compatibility multiple times. A summary of changes is noted below.
:::caution pass
Electron 6 changed the return types of `dialog` API methods. The old `dialog`
methods have been renamed:
| Electron 1 - 5 | Electron 6 |
|:-----------------|:---------------------|
| `showOpenDialog` | `showOpenDialogSync` |
| `showSaveDialog` | `showSaveDialogSync` |
**This change was not properly documented!**
Electron 9 and later require the preference `nodeIntegration: true` in order to
`require('xlsx')` in the renderer process.
Electron 12 and later also require `worldSafeExecuteJavascript: true` and
`contextIsolation: true`.
Electron 14 and later must use `@electron/remote` instead of `remote`. An
`initialize` call is required to enable Developer Tools in the window.
:::
[^1]: See ["Makers"](https://www.electronforge.io/config/makers) in the Electron Forge documentation. On Linux, the demo generates `rpm` and `deb` distributables. On Arch Linux and the Steam Deck, `sudo pacman -Syu rpm-tools dpkg fakeroot` installed required packages.