We're starting a monthly roundup to highlight activity in the Electron community. Each roundup will feature things like new apps, upcoming meetups, tools, videos, etc.

This site is updated with new apps and meetups through pull requests from the community. You can watch the repository to get notifications of new additions or if you're not interested in all of the site's changes, subscribe to the blog RSS feed.

If you've made an Electron app or host a meetup, make a pull request to add it to the site and it will make the next roundup.

New Apps​

	Demio	A Webinar platform built for inbound sales and marketing
	Electorrent	A remote client app for uTorrent server
	PhoneGap	The open source framework that gets you building amazing mobile apps using web technology
	WordMark	A lightweight blog publishing editor for Markdown writers
	UbAuth	App to help developers create access tokens for Uber applications with OAuth 2.0
	HyperTerm	HTML/JS/CSS terminal
	Marp	Markdown presentation writer
	Glyphr Studio	A free, web based font designer, focusing on font design for hobbyists
	BitCrypt	A simple file encryption application for Windows Encrypt your bits
	Trym	Beautiful small app for macOS to help you view, optimize and convert SVG icons
	Booker	Text editor with the power of Markdown
	PhonePresenter	The smartest presentation clicker
	Yout	The new way to watch your playlists from YouTube on desktop

New Meetups​

This is the first post of a series that explains the internals of Electron. This post introduces how Node's event loop is integrated with Chromium in Electron.

There had been many attempts to use Node for GUI programming, like node-gui for GTK+ bindings, and node-qt for QT bindings. But none of them work in production because GUI toolkits have their own message loops while Node uses libuv for its own event loop, and the main thread can only run one loop at the same time. So the common trick to run GUI message loop in Node is to pump the message loop in a timer with very small interval, which makes GUI interface response slow and occupies lots of CPU resources.

During the development of Electron we met the same problem, though in a reversed way: we had to integrate Node's event loop into Chromium's message loop.

The main process and renderer process​

Before we dive into the details of message loop integration, I'll first explain the multi-process architecture of Chromium.

In Electron there are two types of processes: the main process and the renderer process (this is actually extremely simplified, for a complete view please see Multi-process Architecture). The main process is responsible for GUI work like creating windows, while the renderer process only deals with running and rendering web pages.

Electron allows using JavaScript to control both the main process and renderer process, which means we have to integrate Node into both processes.

Replacing Chromium's message loop with libuv​

My first try was reimplementing Chromium's message loop with libuv.

It was easy for the renderer process, since its message loop only listened to file descriptors and timers, and I only needed to implement the interface with libuv.

However it was significantly more difficult for the main process. Each platform has its own kind of GUI message loops. macOS Chromium uses NSRunLoop, whereas Linux uses glib. I tried lots of hacks to extract the underlying file descriptors out of the native GUI message loops, and then fed them to libuv for iteration, but I still met edge cases that did not work.

So finally I added a timer to poll the GUI message loop in a small interval. As a result the process took a constant CPU usage, and certain operations had long delays.

Polling Node's event loop in a separate thread​

As libuv matured, it was then possible to take another approach.

The concept of backend fd was introduced into libuv, which is a file descriptor (or handle) that libuv polls for its event loop. So by polling the backend fd it is possible to get notified when there is a new event in libuv.

So in Electron I created a separate thread to poll the backend fd, and since I was using the system calls for polling instead of libuv APIs, it was thread safe. And whenever there was a new event in libuv's event loop, a message would be posted to Chromium's message loop, and the events of libuv would then be processed in the main thread.

In this way I avoided patching Chromium and Node, and the same code was used in both the main and renderer processes.

The code​

You can find the implemention of the message loop integration in the node_bindings files under electron/atom/common/. It can be easily reused for projects that want to integrate Node.

Update: Implementation moved to electron/shell/common/node_bindings.cc.

Looking for an introduction to Electron? Two new podcasts have just been released that give a great overview of what it is, why it was built, and how it is being used.

Out now:

Hanselminutes: Creating cross-platform Electron apps​

Is Electron "just Chrome in a frame" or is it so much more? Jessica sets Scott on the right path and explains exactly where the Electron platform fits into your development world.

JavaScript Air: Electron Apps​

Electron is becoming more and more of a relevant and popular way of building multi-platform desktop apps with web technologies. Let's get a dive into this awesome tech and see how we can use it to enhance our own experience and our user's experience on the desktop.

If you're looking for an introduction to Electron, give the first a listen. The second goes into more detail about building apps with great tips from Nylas's Evan Morikawa.

We are currently working on two more podcasts that should come out next month, keep an eye on the @ElectronJS Twitter account for updates.

For the last two years, Electron has helped developers build cross platform desktop apps using HTML, CSS, and JavaScript. Now we're excited to share a major milestone for our framework and for the community that created it. The release of Electron 1.0 is now available from electronjs.org.

Electron 1.0 represents a major milestone in API stability and maturity. This release allows you to build apps that act and feel truly native on Windows, Mac, and Linux. Building Electron apps is easier than ever with new docs, new tools, and a new app to walk you through the Electron APIs.

If you're ready to build your very first Electron app, here's a quick start guide to help you get started.

We are excited to see what you build next with Electron.

Electron's Path​

We released Electron when we launched Atom a little over two years ago. Electron, then known as Atom Shell, was the framework we'd built Atom on top of. In those days, Atom was the driving force behind the features and functionalities that Electron provided as we pushed to get the initial Atom release out.

Now driving Electron is a growing community of developers and companies building everything from email, chat, and Git apps to SQL analytics tools, torrent clients, and robots.

In these last two years we've seen both companies and open source projects choose Electron as the foundation for their apps. Just in the past year, Electron has been downloaded over 1.2 million times. Take a tour of some of the amazing Electron apps and add your own if it isn't already there.

Electron API Demos​

Along with the 1.0 release, we're releasing a new app to help you explore the Electron APIs and learn more about how to make your Electron app feel native. The Electron API Demos app contains code snippets to help you get your app started and tips on effectively using the Electron APIs.

Devtron​

We've also added a new extension to help you debug your Electron apps. Devtron is an open-source extension to the Chrome Developer Tools designed to help you inspect, debug, and troubleshoot your Electron app.

Features​

• Require graph that helps you visualize your app's internal and external library dependencies in both the main and renderer processes
• IPC monitor that tracks and displays the messages sent and received between the processes in your app
• Event inspector that shows you the events and listeners that are registered in your app on the core Electron APIs such as the window, app, and processes
• App Linter that checks your apps for common mistakes and missing functionality

Spectron​

Finally, we're releasing a new version of Spectron, the integration testing framework for Electron apps.

Spectron 3.0 has comprehensive support for the entire Electron API allowing you to more quickly write tests that verify your application's behavior in various scenarios and environments. Spectron is based on ChromeDriver and WebDriverIO so it also has full APIs for page navigation, user input, and JavaScript execution.

Community​

Electron 1.0 is the result of a community effort by hundreds of developers. Outside of the core framework, there have been hundreds of libraries and tools released to make building, packaging, and deploying Electron apps easier.

There is now a new community page that lists many of the awesome Electron tools, apps, libraries, and frameworks being developed. You can also check out the Electron and Electron Userland organizations to see some of these fantastic projects.

New to Electron? Watch the Electron 1.0 intro video:

Electron 0.37 was recently released and included a major upgrade from Chrome 47 to Chrome 49 and also several new core APIs. This latest release brings in all the new features shipped in Chrome 48 and Chrome 49. This includes CSS custom properties, increased ES6 support, KeyboardEvent improvements, Promise improvements, and many other new features now available in your Electron app.

What's New​

CSS Custom Properties​

If you've used preprocessed languages like Sass and Less, you're probably familiar with variables, which allow you to define reusable values for things like color schemes and layouts. Variables help keep your stylesheets DRY and more maintainable.

CSS custom properties are similar to preprocessed variables in that they are reusable, but they also have a unique quality that makes them even more powerful and flexible: they can be manipulated with JavaScript. This subtle but powerful feature allows for dynamic changes to visual interfaces while still benefitting from CSS's hardware acceleration, and reduced code duplication between your frontend code and stylesheets.

For more info on CSS custom properties, see the MDN article and the Google Chrome demo.

CSS Variables In Action​

Let's walk through a simple variable example that can be tweaked live in your app.

:root {
  --awesome-color: #a5ecfa;
}

body {
  background-color: var(--awesome-color);
}

The variable value can be retrieved and changed directly in JavaScript:

// Get the variable value ' #A5ECFA'
let color = window
  .getComputedStyle(document.body)
  .getPropertyValue('--awesome-color');

// Set the variable value to 'orange'
document.body.style.setProperty('--awesome-color', 'orange');

The variable values can be also edited from the Styles section of the development tools for quick feedback and tweaks:

KeyboardEvent.code Property​

Chrome 48 added the new code property available on KeyboardEvent events that will be the physical key pressed independent of the operating system keyboard layout.

This should make implementing custom keyboard shortcuts in your Electron app more accurate and consistent across machines and configurations.

window.addEventListener('keydown', function (event) {
  console.log(`${event.code} was pressed.`);
});

Check out this example to see it in action.

Promise Rejection Events​

Chrome 49 added two new window events that allow you to be notified when an rejected Promise goes unhandled.

window.addEventListener('unhandledrejection', function (event) {
  console.log('A rejected promise was unhandled', event.promise, event.reason);
});

window.addEventListener('rejectionhandled', function (event) {
  console.log('A rejected promise was handled', event.promise, event.reason);
});

Check out this example to see it in action.

ES2015 Updates in V8​

The version of V8 now in Electron incorporates 91% of ES2015. Here are a few interesting additions you can use out of the box—without flags or pre-compilers:

Default parameters​

function multiply(x, y = 1) {
  return x * y;
}

multiply(5); // 5

Destructuring assignment​

Chrome 49 added destructuring assignment to make assigning variables and function parameters much easier.

This makes Electron requires cleaner and more compact to assign now:

Browser Process Requires​

const { app, BrowserWindow, Menu } = require('electron');

Renderer Process Requires​

const { dialog, Tray } = require('electron').remote;

Other Examples​

// Destructuring an array and skipping the second element
const [first, , last] = findAll();

// Destructuring function parameters
function whois({ displayName: displayName, fullName: { firstName: name } }) {
  console.log(`${displayName} is ${name}`);
}

let user = {
  displayName: 'jdoe',
  fullName: {
    firstName: 'John',
    lastName: 'Doe',
  },
};
whois(user); // "jdoe is John"

// Destructuring an object
let { name, avatar } = getUser();

New Electron APIs​

A few of the new Electron APIs are below, you can see each new API in the release notes for Electron releases.

show and hide events on BrowserWindow​

These events are emitted when the window is either shown or hidden.

const { BrowserWindow } = require('electron');

let window = new BrowserWindow({ width: 500, height: 500 });
window.on('show', function () {
  console.log('Window was shown');
});
window.on('hide', function () {
  console.log('Window was hidden');
});

platform-theme-changed on app for OS X​

This event is emitted when the system’s Dark Mode theme is toggled.

const { app } = require('electron');

app.on('platform-theme-changed', function () {
  console.log(`Platform theme changed. In dark mode? ${app.isDarkMode()}`);
});

app.isDarkMode() for OS X​

This method returns true if the system is in Dark Mode, and false otherwise.

scroll-touch-begin and scroll-touch-end events to BrowserWindow for OS X​

These events are emitted when the scroll wheel event phase has begun or has ended.

const { BrowserWindow } = require('electron');

let window = new BrowserWindow({ width: 500, height: 500 });
window.on('scroll-touch-begin', function () {
  console.log('Scroll touch started');
});
window.on('scroll-touch-end', function () {
  console.log('Scroll touch ended');
});

Building an Electron application means you only need to create one codebase and design for one browser, which is pretty handy. But because Electron stays up to date with Node.js and Chromium as they release, you also get to make use of the great features they ship with. In some cases this eliminates dependencies you might have previously needed to include in a web app.

There are many features and we'll cover some here as examples, but if you're interested in learning about all features you can keep an eye on the Google Chromium blog and Node.js changelogs. You can see what versions of Node.js, Chromium and V8 Electron is using at electronjs.org/#electron-versions.

ES6 Support through V8​

Electron combines Chromium's rendering library with Node.js. The two share the same JavaScript engine, V8. Many ECMAScript 2015 (ES6) features are already built into V8 which means you can use them in your Electron application without any compilers.

Below are a few examples but you can also get classes (in strict mode), block scoping, promises, typed arrays and more. Check out this list for more information on ES6 features in V8.

Arrow Functions

findTime () => {
  console.log(new Date())
}

String Interpolation

var octocat = 'Mona Lisa';
console.log(`The octocat's name is ${octocat}`);

New Target

Octocat() => {
  if (!new.target) throw "Not new";
  console.log("New Octocat");
}

// Throws
Octocat();
// Logs
new Octocat();

Array Includes

// Returns true
[1, 2].includes(2);

Rest Parameters

// Represent indefinite number of arguments as an array
(o, c, ...args) => {
  console.log(args.length);
};

Chromium Features​

Thanks to all the hard work Google and contributors put into Chromium, when you build Electron apps you can also use cool things like (but not limited to):

• MouseEvent.getModifierState()
• CSS.escape()
• Fetch API Streaming

Follow along with the Google Chromium blog to learn about features as new versions ship and again, you can check the version of Chromium that Electron uses here.

What are you excited about?​

Tweet to us @ElectronJS with your favorite features built into V8 or Chromium.

Since the beginning of Electron, starting way back when it used to be called Atom-Shell, we have been experimenting with providing a nice cross-platform JavaScript API for Chromium's content module and native GUI components. The APIs started very organically, and over time we have made several changes to improve the initial designs.

Now with Electron gearing up for a 1.0 release, we'd like to take the opportunity for change by addressing the last niggling API details. The changes described below are included in 0.35.x, with the old APIs reporting deprecation warnings so you can get up to date for the future 1.0 release. An Electron 1.0 won't be out for a few months so you have some time before these changes become breaking.

Deprecation warnings​

By default, warnings will show if you are using deprecated APIs. To turn them off you can set process.noDeprecation to true. To track the sources of deprecated API usages, you can set process.throwDeprecation to true to throw exceptions instead of printing warnings, or set process.traceDeprecation to true to print the traces of the deprecations.

New way of using built-in modules​

Built-in modules are now grouped into one module, instead of being separated into independent modules, so you can use them without conflicts with other modules:

var app = require('electron').app;
var BrowserWindow = require('electron').BrowserWindow;

The old way of require('app') is still supported for backward compatibility, but you can also turn if off:

require('electron').hideInternalModules();
require('app'); // throws error.

An easier way to use the remote module​

Because of the way using built-in modules has changed, we have made it easier to use main-process-side modules in renderer process. You can now just access remote's attributes to use them:

// New way.
var app = require('electron').remote.app;
var BrowserWindow = require('electron').remote.BrowserWindow;

Instead of using a long require chain:

// Old way.
var app = require('electron').remote.require('app');
var BrowserWindow = require('electron').remote.require('BrowserWindow');

Splitting the ipc module​

The ipc module existed on both the main process and renderer process and the API was different on each side, which is quite confusing for new users. We have renamed the module to ipcMain in the main process, and ipcRenderer in the renderer process to avoid confusion:

// In main process.
var ipcMain = require('electron').ipcMain;

// In renderer process.
var ipcRenderer = require('electron').ipcRenderer;

And for the ipcRenderer module, an extra event object has been added when receiving messages, to match how messages are handled in ipcMain modules:

ipcRenderer.on('message', function (event) {
  console.log(event);
});

Standardizing BrowserWindow options​

The BrowserWindow options had different styles based on the options of other APIs, and were a bit hard to use in JavaScript because of the - in the names. They are now standardized to the traditional JavaScript names:

new BrowserWindow({ minWidth: 800, minHeight: 600 });

Following DOM's conventions for API names​

The API names in Electron used to prefer camelCase for all API names, like Url to URL, but the DOM has its own conventions, and they prefer URL to Url, while using Id instead of ID. We have done the following API renames to match the DOM's styles:

• Url is renamed to URL
• Csp is renamed to CSP

You will notice lots of deprecations when using Electron v0.35.0 for your app because of these changes. An easy way to fix them is to replace all instances of Url with URL.

Changes to Tray's event names​

The style of Tray event names was a bit different from other modules so a rename has been done to make it match the others.

• clicked is renamed to click
• double-clicked is renamed to double-click
• right-clicked is renamed to right-click

Recently Electron added two exciting features: a Mac App Store compatible build and a built-in Windows auto updater.

Mac App Store Support​

As of v0.34.0 each Electron release includes a build compatible with the Mac App Store. Previously an application built on Electron would not comply with Apple's requirements for the Mac App Store. Most of these requirements are related to the use of private APIs. In order to sandbox Electron in such a way that it complies with the requirements two modules needed to be removed:

• crash-reporter
• auto-updater

Additionally some behaviors have changed with respect to detecting DNS changes, video capture and accessibility features. You can read more about the changes and submitting your app to the Mac App store in the documentation. The distributions can be found on the Electron releases page, prefixed with mas-.

Related Pull Requests: electron/electron#3108, electron/electron#2920

Windows Auto Updater​

In Electron v0.34.1 the auto-updater module was improved in order to work with Squirrel.Windows. This means that Electron ships with easy ways for auto updating your app on both OS X and Windows. You can read more on setting up your app for auto updating on Windows in the documentation.

Related Pull Request: electron/electron#1984

There have been some interesting updates and talks given on Electron recently, here's a roundup.

Source​

Electron is now up to date with Chrome 45 as of v0.32.0. Other updates include...

Better Documentation​

We have restructured and standardized the documentation to look better and read better. There are also community-contributed translations of the documentation, like Japanese and Korean.

Related pull requests: electron/electron#2028, electron/electron#2533, electron/electron#2557, electron/electron#2709, electron/electron#2725, electron/electron#2698, electron/electron#2649.

Node.js 4.1.0​

Since v0.33.0 Electron ships with Node.js 4.1.0.

Related pull request: electron/electron#2817.

node-pre-gyp​

Modules relying on node-pre-gyp can now be compiled against Electron when building from source.

Related pull request: mapbox/node-pre-gyp#175.

ARM Support​

Electron now provides builds for Linux on ARMv7. It runs on popular platforms like Chromebook and Raspberry Pi 2.

Related issues: atom/libchromiumcontent#138, electron/electron#2094, electron/electron#366.

Yosemite-style Frameless Window​

A patch by @jaanus has been merged that, like the other built-in OS X apps, allows creating frameless windows with system traffic lights integrated on OS X Yosemite and later.

Related pull request: electron/electron#2776.

Google Summer of Code Printing Support​

After the Google Summer of Code we have merged patches by @hokein to improve printing support, and add the ability to print the page into PDF files.

Related issues: electron/electron#2677, electron/electron#1935, electron/electron#1532, electron/electron#805, electron/electron#1669, electron/electron#1835.

Atom​

Atom has now upgraded to Electron v0.30.6 running Chrome 44. An upgrade to v0.33.0 is in progress on atom/atom#8779.

Talks​

GitHubber Amy Palamountain gave a great introduction to Electron in a talk at Nordic.js. She also created the electron-accelerator library.

Building native applications with Electron by Amy Palomountain​

Ben Ogle, also on the Atom team, gave an Electron talk at YAPC Asia:

Building Desktop Apps with Web Technologies by Ben Ogle​

Atom team member Kevin Sawicki and others gave talks on Electron at the Bay Are Electron User Group meetup recently. The videos have been posted, here are a couple:

The History of Electron by Kevin Sawicki​

Making a web app feel native by Ben Gotow​

Join us September 29th at GitHub's HQ for an Electron meetup hosted by Atom team members @jlord and @kevinsawicki. There will be talks, food to snack on, and time to hangout and meet others doing cool things with Electron. We'll also have a bit of time to do lightning talks for those interested. Hope to see you there!

Talks

• Jonathan Ross and Francois Laberge from Jibo will share how they use Electron to animate a robot.
• Jessica Lord will talk about building a teaching tool, Git-it, on Electron.
• Tom Moor will talk about the pros and cons of building video and screen sharing on Electron with speak.io.
• Ben Gotow will preview N1: The Nylas Mail Client and talk about developing it on Electron.

Details​

• Location: GitHub HQ, 275 Brannan Street, San Francisco, CA, 94107
• Date: Tuesday, September 29th, 2015
• Time: 6pm - 9pm
• RSVP: ti.to/github-events/electron-meetup