Learn Electron, Pm2 and Svelte

JavaScript community has been shaken recently by a release of Svelte 3 and for a good reason - it's a completely different approach than React or Vue. To quote the docs:

"[Svelte](https://svelte.dev/) is a radical new approach to building user interfaces. Whereas traditional frameworks like React and Vue do the bulk of their work in the browser, Svelte shifts that work into a compile step that happens when you build your app."

**The best part?** If you have 26 spare minutes you can learn the basics of Svelte 3 and start building your own apps with it!

Enjoy!



The magical disappearing UI framework

 - The web's JavaScript bloat crisis, solved. Svelte turns your templates into tiny, framework-less vanilla JavaScript.
 - Simple and familiar. Build apps out of composable, easy-to-write blocks using languages you already know.
 - Super fast, rock solid. Compile-time static analysis ensures the browser does no more work than it needs to.

svelte

Up and running with Svelte 3

Electron is a framework that makes it easy to create cross-platform desktop apps with JavaScript, HTML, and CSS. Electron and open-source tools give you everything you need to create a compelling desktop app--native user interface elements like menus and dialogs, installers, auto-updates, and more. 

This course will teach you the core concepts of Electron so that you can leverage it to create your own desktop application for macOS and Windows. 

We'll go over:
- Creating user interfaces in Electron (both HTML based and native)
- Understanding Electron's multi-process architecture 
- Shipping your app to users

Electron is a framework for creating native applications with web technologies like JavaScript, HTML, and CSS.

electron

Build a desktop application with Electron

In this lesson we’ll load javascript into the BrowserWindow and display the Electron version on the page. Loading javascript into Electron is almost exactly the same as loading it into the browser, however it is a best practice to use the `require` syntax.

Load JavaScript in an Electron BrowserWindow

A main menu is a hallmark of native desktop applications. Electron makes it easy to create native menus and menu items in JavaScript.

We’ll go over creating a menu template using `Menu.buildFromTemplate` and then setting it as the main application menu via `Menu.setApplicationMenu`. 

Create a native desktop system menu with the Electron Menu module

In this lesson we'll learn about `dialog.showMessageBox` . This is the most basic Electron dialog but it offers lots of customization options, such as `type`, `icon`, `title`, and `buttons`. Some of these options vary by platform, so we'll also look at how things differ between Windows and Mac. 

Display native desktop dialog windows with Electron

In this video, we'll learn how to save and open a file using native dialogs in Electron. First, we'll use `dialog.showSaveDialog` to display a native save dialog and use `dialog.showErrorBox` to display an error message if the save failed. Then, we'll open the file we saved using `dialog.showOpenDialog`. Finally, we'll look at how these dialogs look on Windows vs Mac.

Save/Open a file with an Electron dialog window

Dealing with multiple processes in an application is new for many JavaScript developers. We’ll go over what exactly a process is and what the primary responsibilities of the main and renderer processes are. The main process is primarily responsible for creating native UI elements and managing the application lifecycle, while the renderer process runs the HTML based UI. Accordingly, different APIs are available in each process. 

Understand Electron’s main and renderer process architecture

In Electron, we often need to coordinate actions between multiple processes. For example, if a user clicks a button in a renderer process that makes a new `browserWindow` open, we need to be able to send a message to the main process that triggers this action. We’ll look at how to do just that using the `ipcRenderer` and `ipcMain` modules.

Communicate between Electron processes using IPC

`remote` allows you to seamlessly interact with main process modules as if they were in the renderer process. It’s a super useful abstraction over IPC. We’ll learn how to use it and how to avoid some potential gotchas it has. 

[Devtron](https://electron.atom.io/devtron/) is a devtools extension that the Electron team has made. We’ll be using it to view all of the IPC that happens in our application. In this lesson we’ll learn how to include and use it in our code. 

Communicate between Electron processes using the remote module

Every Electron application needs a custom icon. Mac needs an `icns` file and Windows needs an `ico` file. We'll learn how to use a npm module, `electron-icon-maker`, that takes a 1024x1024 PNG and then outputs all the files we need. 

Create an icon for your Electron app

We’ve been running our app in a development environment using the Electron executable. Now let’s learn how to package our app into a `.app` or `.exe` file so that we can distribute it to other users. Electron doesn't provide this functionality out of the box, so we'll use a popular and easy-to-use npm package called [electron-builder](https://github.com/electron-userland/electron-builder) to handle the details. electron-builder will automatically grab our `.ico` or `.icns` file and use that as our app's icon. 

Package your Electron application into a executable file with electron-builder

Code signing ensures that your app was created and distributed by you or your company and has not been modified since it was built. It is done via a special code signing certificate issued by a trusted authority. While you can distribute your Electron app without signing it; code signing is a security best practice and is a prerequisite to implementing auto-updates in your app. We’ll walkthrough how to integrate code signing into your electron-builder build process, what happens when you don't sign your application, and how to verify it's been signed correctly. 

This lesson assumes that you have already purchased code signing certificates from Apple and one of Microsoft's trusted vendors and have exported the certificate as a `p12` or `pfx` file. 

Code sign your Electron application with electron-builder

Once users are using your app, you need a way to ship new features and fixes to them. In this lesson, we’ll learn how to implement auto-updates in your app, which allows you to distribute updates to your application seamlessly. We'll go over how to integrate with Electron's `autoUpdater` module to check for an update and display a prompt to update once it's been downloaded. For our server side implementation we'll just use a plain file server to keep things simple. 


Ship updates to your Electron app with `autoUpdater` (Mac)

In this lesson, we'll go over a few differences in implementing auto-updates on Windows like handling `Squirrel.Windows` startup events and configuring `electron-builder` to build for a `Squirrel.Windows` target.

Ship updates to your Electron app with `autoUpdater` (Windows)

Take the first step in learning how to create native desktop applications with Electron. We'll set up a package.json, create an npm start script to launch our app in development, and create a browser window and load a local HTML file into it.

An important concept to understand about Electron is it's multi-process architecture. The main process creates web pages by creating `BrowserWindow` instances, manages application lifecycle events, and more. Each `BrowserWindow` instance runs the web page in its own renderer process. 

Create a "Hello World" app using Electron

In this lesson we'll learn how to load CSS in an Electron BrowserWindow, which is just like loading CSS into the browser. We’ll also use the `ready-to-show` event to only display our BrowserWindow when its rendering is complete.

Load CSS in a Electron BrowserWindow

PM2 is a production process manager for Node.js applications with a built-in load balancer. It allows you to keep applications alive forever, to reload them without downtime and to facilitate common system admin tasks.

This video shows how to enable features in your pm2 config file that allow you to prevent runaway apps from bringing your server down. Setting max memory used, number of running processes allowed and maximum restart attempts are all covered.

Controlling runaway apps using pm2

In this lesson you will learn how to attach Event Handlers to buttons and input fields. Event handlers normally follows the `on:[event]` format. If you are making use of two way binding you should use `bind:` instead, for example an input field could use bind:value.

Use Event Handlers in Svelte 2

Svelte is a new approach to building user interfaces. 

Instead of doing the vast majority of work at the runtime as other frameworks do, Svelte shifts that work into the _compile_ step which happens when you build your app. As such, you're shipping heavily optimized code to your users.

In this quick lesson we are going to learn how to create a brand new project with Svelte 3 from scratch.

Create a new project with Svelte 3

In most Web applications we want to be able to render different HTML markup depending on values passed in from JavaScript code.

In this lesson we are going to learn how to render JavaScript variable in HTML markup when using Svelte 3.

Add data to HTML markup using Svelte 3

In Svelte 3, the same as in regular HTML we can add CSS styles to a component and this is what we're going to learn in this lesson.

Important note - styles are _scoped to the component_ which means that if we style a `h1` tag in component A, it won't automatically affect `h1` tags in component B.