Learn Go, Nginx 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

Go is an open source programming language that makes it easy to build simple, reliable, and efficient software. It is used frequently in the container ecosystem by projects such as Kubernetes (container orchestration), Docker (containers), and Cilium (BPF networking).

This playlist is a collection of videos that will start you off on your Golang journey.

Go is an open-source programming language that makes it easy to build simple, reliable, and efficient software.

Golang from Scratch

Go is a server-side language, but today we can compile Go code to WebAssembly as well - making it possible for us to bring programs written in minimalistic Go code into the browser!

With this collection, we will learn how to compile and run Go WebAssembly programs in Node.js and the browser, and how our Go code can interop with JavaScript and manipulate the DOM. We will also talk about configuring our VS Code workspace and optimizing the Go WASM binary size.

WebAssembly with the Go Language

This collection of lessons will cover a variety of topics that teach you how to work with slices and arrays in go. You'll learn how to declare them, create them using literal syntax, iterate over them, add to them, remove from them and other useful things.

Learn about slices and arrays in Go

Creating forms is one of the simplest and most complicated things at the same time. A basic form consists of many different things happening, we have to retain the value, we have to keep watch of validation and we have to show error messages when something is invalid, this is on both the fields and on the entire form itself if we send a request off to the backend service.

So we're going to create a form using just the normal svelte features. Then we'll look into creating a form using the svelte forms lib. 

Create forms in Svelte with Svelte Forms Lib

NGINX is a free, open-source, high-performance HTTP server and reverse proxy, as well as an IMAP/POP3 proxy server. 

nginx

Learn about the concepts of managing data within Docker volumes, including all of the commands to create and manage volumes. We'll demonstrate how to mount a Docker volume to one or many containers by creating and mounting a volume to an Nginx proxy, and then verify the output with curl. You'll also see how changes to files within volumes of one container propagate to other containers with the same volume mounted, and learn various commands to inspect Docker volumes.

Manage Data within Docker Volumes

Learn how to setup an Nginx proxy server with Docker that sits in front of a Node.js app. You can use a proxy to control the flow of frontend requests hitting your app, as well as to achieve better performance and scalability. We'll create a sample Node.js app, configure a default Nginx configuration file for proxying web requests, build both Node.js and Nginx Docker images, and learn how to link everything up and get it running with Docker specifics.

Setup an Nginx Proxy for a Node.js App with Docker

Node.js apps built with Docker cannot scale horizontally by themselves. In this lesson we will spawn out multiple Node.js processes/containers, and move the incoming request handler to an Nginx proxy to load balance and properly scale our Node.js app.

Scale Docker Horizontally with Nginx Load Balancing

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

We'll cover a small Golang program that prints a string to the terminal, showing how to set up an executable program, import a package, and build a binary.

Getting Started with Hello World in Go

Returning multiple values from a function is a common idiom in Go, most often used for returning values along with potential errors. We'll go over how to return multiple values from a function and use those values in our program.

Returning Multiple Values from a Function in Go

Functions are as useful in Go as many other programming languages. In this lesson we write a function that operates on numbers covering the func keyword, argument and return signatures, and writing the function body.

Writing a Function that Multiplies a Number by Two in Go

Golang has testing tools built into the standard go tool and the standard library. Here is how to write a unit test on a function so that you can run it with `go test`.

Writing a Unit Test in Go

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.

Add styles to Svelte 3 component

It's highly unlikely that we'd like to have an entire app in a single file. Instead, what we'd like to do is to spread our code across multiple components and render them in one another.

In this lesson we are going to learn how to create a `<Surname />` Svelte 3 component which we're going to use in our main `App.svelte` file to display a user's surname.

Create a new Svelte 3 component to render it inside of another component

One of the key advantages of having a component system is the ability to render the component differently based on what kind of properties (shortened to 'props' in Svelte) were passed in to the component.

In this lesson we are going to learn how to declare properties inside of a Svelte component and how to pass in data to be rendered inside of a `<UserInfo />` component. We're also going to learn how to use default props which are used if a value for a property was not passed in.

Declare and pass in properties to a Svelte 3 component

Svelte automatically updates the DOM when your component's state changes. Often, some parts of a component's state need to be computed from other parts. This is where _reactive declarations_ come in.

In this lesson we are going to learn how to use reactive declarations to re-compute (and render) square of a counter value in a simple counter example whenever user clicks on a button.

Use reactive declarations to compute component state in Svelte 3

Quite often we need to be able to loop over and render a list of data that (for example) is returned from the backend. 

In this lesson we are going to learn how to use `each` block from Svelte to iterate over a list of data and render a list of European cities. We're also going to learn how to get the current `index` while iterating over a list, as well as how to destructure a currently iterated over element of the array.

Loop over and render a list of data using an `each` block in Svelte 3

The whole magic of webapps is that users can interact with our code via various DOM events and Svelte is no exception in that regard.

In this quick lesson we're going to learn how to use DOM events in Svelte 3 as well as how to use event _modifiers_ to alter DOM event behaviour (such as `once` and `preventDefault`)