Learn Flutter, Most 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

Most.js is a toolkit for reactive programming. It helps you compose asynchronous operations on streams of values and events, e.g. WebSocket messages, DOM events, etc, and on time-varying values, e.g. the "current value" of an <input>, without many of the hazards of side effects and mutable shared state.

most

Most provides many means for creating streams, the simplest of which is the `of` function. In this lesson, we demonstrate the use of `of` to lift a single value into a stream. We also show off the `just` alias of `of`, as well as, a common method for currying a function.


Create Streams From Single Values With Most.js

One of the more powerful functions for creating streams in MostJS is the `from` function.

In this lesson, we use `from` to create streams from various Javascript Iterables, take a look at how to throw generator functions into the mix and, for good measure, take a sneak peek at how we can limit our streams using a function called `take`.

As a bonus, we see what it looks like to use `Function.prototype.bind` for a quick and dirty way to partially apply arguments to a function.

Create Streams From Iterables With Most.js

Unlike RxJS, Most does not include an observable-based AJAX helper utility. However, it can be very convenient to have one, because it allows you to use streams to do things like declaratively handling errors & setting up cancellation. In this lesson, we use currying & functional composition to create an Observable-based wrapper around the fetch API with Ramda & Most.

Create an Observable-Based Fetch Wrapper Using Ramda & Most

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

Flutter allows you to build beautiful native apps on iOS and Android from a single codebase.

flutter

In this lesson, we will cover Interfaces and Mixins. Interfaces act as a contract containing properties and methods that a class must define once it “implements” this interface. Mixins are Dart’s way of sharing properties and methods from multiple classes, since by design Dart adopts a single-inheritance model.

Define Interfaces and Share Class Members through Mixins in Dart

Futures represent a computation that does not complete immediately. Where a normal function returns a result, an asynchronous function returns a Future that will eventually contain the result. These are similar to Promises in JavaScript. In this lesson, we will learn how to program asynchronously by writing logic to capture values that are returned at a later time.

Capture and Return Asynchronous Values with Futures in Dart

Streams represent a sequence of asynchronous events. Each event is either a data event, also called an element of the stream, or an error event, which is a notification that something has failed. When a stream has emitted all its events, a single "done" event will notify the listener that the end has been reached. In this lesson, we will learn how we can capture and handle streaming data, working with various Stream classes.

Capture and Handle Data Sequences with Streams in Dart

In this lesson we’ll learn how to fetch & then display data from an API over the network in a Flutter application using the http package.

Fetching & Displaying Data from an API in Flutter using the http Package

Pub is a package management tool that makes it easy for you to install, use, share Dart libraries, command-line tools and other assets. It comes as part of the Dart SDK, and requires a dependency file called pubspec.yaml.

Manage Package Dependencies with Pub

We will learn how to work with Strings using a variety of methods made available in the **dart:core** library. We will explore the top methods for working with String values.

Learn more about Strings at https://api.dartlang.org/stable/2.2.0/dart-core/String-class.html

Manipulate Strings in Dart

We will learn how to work with Lists using a variety of methods made available in the **dart:core** library. We will explore the top methods for working with List type collections.

Learn more about Lists at https://api.dartlang.org/stable/2.2.0/dart-core/List-class.html

Manipulate Lists/Arrays in Dart

Learn how to add a LinearGradient to your BoxDecoration widgets. This allows you to create fancy backgrounds within your Flutter applications!

Create a LinearGradient background with Flutter

In this lesson we look at navigating between two pages using the `Navigator`. 

Navigate between pages using the Flutter Navigator

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.