feat: [Electron Demo] - implement OS level file associations via dist build.

docz/static/electron/index.js

@@ -1,5 +1,6 @@
 const XLSX = require("xlsx");
 const electron = require("@electron/remote");
+const { ipcRenderer } = require('electron');
 
 // --- Supported Extensions ---
 const EXTENSIONS =
@@ -202,3 +203,16 @@ async function readFile(files) {
 
 // --- Initial Setup ---
 attachDropListeners();
+
+// handle file opening events from the main process
+ipcRenderer.on('file-opened', async (_evt, filePath) => {
+  console.log('Received file-opened event:', filePath);
+  showSpinner();
+  // yield to event loop to render spinner
+  await new Promise(r => setTimeout(r, 50));
+  renderWorkbookToTables(XLSX.readFile(filePath));            // already in your helper list
+  showLoadedFileUI(filePath.split(/[/\\]/).pop());
+  hideSpinner();
+  hideDropUI();
+  showExportBtn();
+});

docz/static/electron/main.js

@@ -6,6 +6,57 @@ require('@electron/remote/main').initialize(); // required for Electron 14+
 
 var win = null;
 
+const EXT_REGEX = /\.(xls|xlsx|xlsm|xlsb|xml|csv|txt|dif|sylk|slk|prn|ods|fods|htm|html|numbers)$/i;
+const pendingPaths = [];        // any paths that arrive before the window exists
+
+
+// send file opening events to renderer
+function sendToRenderer(filePath) {
+  if (win && win.webContents) {
+    win.webContents.send('file-opened', filePath);
+  } else {
+    pendingPaths.push(filePath);
+  }
+}
+
+function firstSpreadsheetFromArgv() {
+  const args = process.defaultApp             // dev: electron .
+               ? process.argv.slice(2)        // skip electron executable & dir
+               : process.argv.slice(1);       // skip packaged exe
+  return args.find(a => EXT_REGEX.test(a));      // undefined if none
+}
+
+/* ---- 1️⃣ single-instance guard (needed for Windows / Linux) ---- */
+// on windows and linux, opening a file opens a new instance of the app, this prevents that.
+const gotLock = app.requestSingleInstanceLock();
+if (!gotLock) app.quit();
+else {
+  app.on('second-instance', (_e, argv) => {                  // emitted in *primary* instance
+    const fp = argv.find(a => EXT_REGEX.test(a));
+    if (fp) sendToRenderer(fp);
+    if (win) { win.show(); win.focus(); }
+  });
+}
+
+/* ---- 2️⃣ platform-specific “open file” hooks ---- */
+app.on('open-file', (event, fp) => {                         // macOS Dock / Finder 
+  event.preventDefault();
+  sendToRenderer(fp);
+});
+
+app.on('open-url', (event, url) => {                         // you can add a custom protocol if you want to handle URLs
+  event.preventDefault();
+  sendToRenderer(url.replace('file://', ''));                // crude, adjust if you keep deep-links
+});
+
+/* ---- 3️⃣ normal start-up, harvest argv ---- */
+app.whenReady().then(() => {
+  const fp = firstSpreadsheetFromArgv();  // Windows & Linux first launch
+  if (fp) pendingPaths.push(fp);
+  createWindow();
+});
+
+/* ---- 4️⃣ create the window ---- */
 function createWindow() {
   if (win) return;
   win = new electron.BrowserWindow({
@@ -18,12 +69,15 @@ function createWindow() {
     }
   });
   win.loadURL("file://" + __dirname + "/index.html");
-  require('@electron/remote/main').enable(win.webContents); // required for Electron 14+
-  win.webContents.openDevTools();
+  require('@electron/remote/main').enable(win.webContents); // required for Electron 14
+  if (process.env.NODE_ENV === 'development') win.webContents.openDevTools(); // only open devtools in development
   win.on('closed', function () { win = null; });
+  win.webContents.once('did-finish-load', () => {
+    pendingPaths.splice(0).forEach(sendToRenderer);
+  });
 }
 if (app.setAboutPanelOptions) app.setAboutPanelOptions({ applicationName: 'sheetjs-electron', applicationVersion: "XLSX " + XLSX.version, copyright: "(C) 2017-present SheetJS LLC" });
-app.on('open-file', function () { console.log(arguments); });
+
 app.on('ready', createWindow);
 app.on('activate', createWindow);
 app.on('window-all-closed', function () { if (process.platform !== 'darwin') app.quit(); });

docz/static/electron/package.json

@@ -12,7 +12,8 @@
   "scripts": {
     "start": "electron-forge start",
     "package": "electron-forge package",
-    "make": "electron-forge make"
+    "make": "electron-forge make",
+    "dist": "electron-builder"
   },
   "devDependencies": {
     "@electron-forge/cli": "7.8.0",
@@ -20,8 +21,28 @@
     "@electron-forge/maker-rpm": "7.8.0",
     "@electron-forge/maker-squirrel": "7.8.0",
     "@electron-forge/maker-zip": "7.8.0",
-    "electron": "35.1.2"
+    "electron": "35.1.2",
+    "electron-builder": "^26.0.12"
   },
+
+  "build": {
+    "appId": "com.sheetjs.electron",
+    "fileAssociations": [
+      {
+        "ext": [
+          "xls","xlsx","xlsm","xlsb","xml","csv","txt","dif",
+          "sylk","slk","prn","ods","fods","htm","html","numbers"
+        ],
+        "name": "Spreadsheet / Delimited File",
+        "description": "Spreadsheets and delimited text files opened by SheetJS-Electron",
+        "role": "Editor"
+      }
+    ],
+    "mac":   { "target": "dmg"  },
+    "win":   { "target": "nsis" },
+    "linux": { "target": "deb"  }
+  },
+
   "config": {
     "forge": {
       "packagerConfig": {},

docz/static/electron/styles.css

@@ -288,6 +288,7 @@ summary:focus-within {
 .sheetjs-tab-content {
     cursor: pointer;
     padding: 1rem;
+    overflow-x: auto;
 }
 
 /* =====================