Electron-File-Access-Test

client.js

fetch('/load_file', {
    method: "POST",
    headers: {'Content-Type': 'application/json'},
    body: JSON.stringify({file: "public/example.json"})
}).then(response => response.text()).then(a=>{console.log(a)})

example.json

{"hello": "world"}

index.html

<script src="client.js"></script>

main.js

const { app, BrowserWindow } = require('electron/main')
const express = require('express');
const fs = require('fs');
const PORT = 5500;
const USE_ELECTRON = true
let win
function createWindow () {
	win = new BrowserWindow({width: 800,height: 600})
	win.loadFile('public/index.html')
}
const express_app = express()
express_app.use(express.static('public'))
express_app.use(express.json())
express_app.post('/load_file', (req, res) => {
	fs.readFile(req.body["file"], 'utf8', function(err, data){
		res.send(data)
	})
})
if (USE_ELECTRON) {
	app.whenReady().then(() => {createWindow()})
	app.on('window-all-closed', () => {
		if (process.platform !== 'darwin') {app.quit()}
	})
}else{
	express_app.listen(PORT, () => {
		console.log(`Server is running on http://localhost:${PORT}`);
    })
}

package.json

{
  "name": "electron-save-files-test",
  "version": "1.0.0",
  "description": "",
  "main": "main.js",
  "scripts": {
    "start": "electron ."
  },
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "electron": "^29.1.5"
  },
  "dependencies": {
    "express": "^4.19.1"
  }
}