Learn Lodash, React-storybook 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

[Lodash](https://lodash.com/docs/) is a collection of utilities that have become a staple of modern web development. This collection will show you how to re-create its most common methods using simple JavaScript techniques available in any modern web browser. In addition to re-building tools like `_.merge`, `_.get` and `_.debounce` from scratch you will also learn how to replace them completely in some cases with modern syntax such as [optional chaining](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Optional_chaining), [nullish coalescing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Nullish_coalescing_operator) and [Object.fromEntries](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/fromEntries).

This collection should interest the following groups:
- Those who want to better understand common JavaScript patterns
- Engineers who want to reduce their dependence on Lodash (for performance or other reasons)
- Candidates preparing for a technical job interview (where it is common to be asked how to implement some of these methods).

JavaScript® (often shortened to JS) is a lightweight, interpreted, object-oriented language with first-class functions, most known as the scripting language for Web pages, but used in many non-browser environments as well such as node.js or Apache CouchDB. It is a prototype-based, multi-paradigm scripting language that is dynamic, and supports object-oriented, imperative, and functional programming styles.

javascript

Recreating Popular JavaScript Utility Methods from Lodash

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

React is one of the web’s most popular frameworks for building JavaScript applications. 

If you know what you’re doing, React can drastically simplify how you build, use, and maintain code.

Whether you’re a React newbie or you’re ready for advanced techniques, you can level-up with egghead. Explore our in-depth courses, lessons, and community resources to build more powerful applications and crack open your career.

react

In this lesson, we show how to setup React Storybook into an existing React project. We’ll go through common configuration files and how to adjust them.

Add React Storybook to a Project 

Components trigger actions via function props to notify of events that occur within the Component. We can inspect those events using React Storybook.

Inspect Component Events with React Storybook

A modern JavaScript utility library delivering modularity, performance & extras.

lodash

This lesson shows how to refactor your old loops into using a simpler and more powerful lodash-style. We will start by looking at how many people traditionally write JavaScript `for` loops and then talk about the alternate style and benefits that Lodash offers.

Lodash: Refactoring Simple For Loops

AngularJS is an open-source JavaScript framework, maintained by Google, that assists with running single-page applications. Its goal is to augment web-based applications with model–view–controller (MVC) capability, in an effort to make both development and testing easier.

angularjs

Lodash has an enormous amount of utility functions for dealing with collections and objects in javascript. You can use it in your AngularJS applications to "debounce" user input, or add delay between user actions. This is a common technique for text input to hold firing service calls until the user stops typing for a fraction of a second.

Debounce (delay) User Input in AngularJS with Lodash



[React Storybook](https://github.com/kadirahq/react-storybook) is a UI component development environment for React.
With that, you can develop UI components without running your app.

Here I show how to get started with React Storybook.
For more information, have a look at our [documentation](https://getstorybook.io/docs).

Getting Started with React Storybook

React Component stories can be dynamically loaded into React Storybook instead of doing it manually every time.

Load React Storybook Stories Dynamically

Imagine if looking at your business logic read as simple as a story from a children's book. That's exactly what we'll cover by learning how to compose small pieces of business logic and also set them up for further composition in the future.

We're showing a list of fictional tweets in a trivial React component created with create-react-app, however the example is not React specific and can be applied to any framework/environment.

Our example will refactor out business logic from a non-composable function to small composable pieces. To accomplish this we'll be using flow, filter and map from lodash/fp, which is included in the regular lodash npm package.

This approach works well in any environment where you're not relying on object references to your original data, as our functional approach creates new collection objects instead of mutating them.

Guide to lodash/fp: https://github.com/lodash/lodash/wiki/FP-Guide


Refactor Business Logic to Composable Functions with Lodash

Lodash's "sortBy" method helps you sort data in your collections and "sortedIndex" helps you find where to place new data. In this video, John walks you through how to use each of these methods and how they can work together.

Lodash - sortBy and sortedIndex

Property access in Javascript can be problematic - especially when dealing with nested Objects and Arrays. Doing it manually and in a safe manner requires tons of boilerplate inside conditionals and results in a defensive style of coding. In this lesson we look at why this is a problem & how to overcome it using the `get` method from the popular utility library `Lodash`

Safer property access with Lodash's 'get' method

Logic often gets added to our loops. We need to iterate over a collection, and get the sum of values, for instance. This approach can lead to complicated methods, that are hard to test. Using Lodash (Underscore), we are going to extract logic in a large loop body into well named methods. The result will be cleaner and easier to understand.

Refactoring: Replace Loop with Collection Closure using Lodash

Story is the smallest unit of React Storybook. A story describes a React Component, and its various states and variations. Stories can describe complex components with dynamic properties and data loaded from a service. In this lesson we will write our first React Storybook story.

Write the First React Storybook Story

Learn how to use Object.assign to combine multiple objects together. This pattern is helpful when writing libraries that have a set of default options where you want to allow a user to override specific options. You'll also learn how to use a third party library to recursively merge nested objects together.

Combine Objects with Object.assign and Lodash merge

Lodash is a toolkit of Javascript functions that provides clean, performant methods for manipulating objects and collections. It is a "fork" of the Underscore library and provides additional functionality as well as some serious performance improvements. If you aren't using Lodash, you should be.

Introduction to Lodash

React Storybook allows for easy snapshot testing integration with Facebook's Jest testing framework. Snapshot testing allows you to capture the state of your UI and then notify you when that UI has been altered. We can easily create and update snapshots with Storybook!
 




Jest Snapshot Testing with React Storybook

Storybook is a UI component development environment for React, Vue, and Angular. With that, you can develop UI components without running your app.

Here I show how to set up Storybook to display React components from scratch.

Set up Storybook for React from Scratch

Vue (pronounced /vjuː/, like view) is a progressive framework for building user interfaces. Unlike other monolithic frameworks, Vue is designed from the ground up to be incrementally adoptable. The core library is focused on the view layer only, and is very easy to pick up and integrate with other libraries or existing projects. On the other hand, Vue is also perfectly capable of powering sophisticated Single-Page Applications when used in combination with modern tooling and supporting libraries.

In this lesson we'll go through the process of setting up Storybook for Vue. We'll use Vue CLI to create a new Vue application and Storybook CLI to setup some initial stories and config. Storybook can help you develop UI components in an isolated area without running your full application.

*Additional Resources*
https://medium.com/storybookjs/introducing-storybook-for-vue-940f222541c5
https://storybook.js.org/basics/guide-vue/

 Getting Started With Storybook for Vue

Storybook is a UI component development environment for React, Vue, and Angular. With that, you can develop UI components without running your app.

Here I show the best configuration for React Storybook, and walk through adding your very first React Component and Story to your Storybook.

Add your first React Story to Storybook

Storybook is a UI component development environment for React, Vue, and Angular. With that, you can develop UI components without running your app.

Here I show how to add a landing/welcome page to your Storybook, so that first-time viewers get to read a message from you or have some orientation around the structure of the Storybook you are building. We also introduce the idea of sequential additions to your Storybook config so you can get a sense of how to modify it for your own needs.