Learn Npm, Polymer and Svelte

npm is the package manager for JavaScript. Find, share, and reuse packages of code from hundreds of thousands of developers — and assemble them in powerful new ways.

Introduction to Monorepos with NPM Workspaces

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

You can’t be everywhere at once. Neither can node packages. But with a utility called npx — included in npm v5.2 and later — you can interact and run with node modules even if they’re not downloaded locally. The same is true for gists and remote branches of GitHub. As long as npm installed, your work can be wherever you are.

This course from Elijah Manor unlocks the power of the npx utility. Over 17 minutes, we will examine the npx package runner and look through various scenarios where the tool is helpful when running node packages from the command line. You’ll learn to use npm to:

- test out various versions of a package
- run packages without globally installing
- run code directly from GitHub
- make working with packages much easier

Execute npm Package Binaries with the npx Package Runner

npm is like a giant library of code building blocks. There are tons of these “blocks”, aka “packages” that we can compose together to build cool things. We can use packages by other developers, but we can also write and publish our own. 

In this course we will learn how to create, publish, and update our own packages. We will create a JavaScript utility module to filter out sensitive words from a string, including tests and development file watching. We will then cover publishing and updating our package. This same approach can be used to create and publish other types of packages too like components (React, Angular, Web Components etc.) and command line interfaces.

Publish JavaScript packages on npm

In this course we will introduce the topic of using npm scripts as a build tool. We will start simple and then continue to build a small website as we introduce new topics. By the end of the course, you'll know how to get started and what tools and techniques are needed for you to create your own set of build scripts.

How to Use npm Scripts as Your Build Tool

Polymer is a framework created at Google for building reusable web components.

We use HTML elements every day such as div, a, button, form, and table. All HTML elements provide some sort of API of attributes, properties, methods and events that we use to manipulate them. Generally, web elements are styled in a particular way by default, and also allow us to customize their styling with CSS.

Polymer allows you to build fully custom web elements of your own for more complex components composed of the building blocks you are used to with the standard set of HTML elements.

This course is an introduction to Polymer, and should get you started building your own customizable web elements that you can use on their own, or even with your favorite framework like Angular or React!

The Polymer library provides a set of features for creating custom elements. These features are designed to make it easier and faster to make custom elements that work like standard DOM elements.

polymer

Creating Custom Web Elements with Polymer 2

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

A lot of the power behind npm scripts is creating custom scripts that are outside the basic set that npm natively understands. In this lesson we will install the ESLint node package, create a new eslint npm script, briefly discuss about environment variables and how npm knows where to find your binary, and then execute our custom script from the command line.

Create a custom npm script

Often times you’ll have variations that you’ll want to make to your npm scripts and repeating yourself is inefficient and verbose. Instead you can create a base script and pass arguments into it from another script.

Pass arguments to npm scripts

In this lesson we will look at pulling out complex npm script logic into an external JavaScript file. Instead of writing bash scripts you can leverage your JavaScript abilities to automate your build process. We’ll use some helper node modules such as shelljs, opn-cli, and babel-cli. 

Create a node script to replace a complex npm script

In addition to package.json level variables (such as name and version), you can have custom conf settings that can be used in your npm scripts. These config values can be overridden outside of the package.json by using the npm config set command if necessary.

Use custom config settings in your npm scripts

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

The React team has an official Command Line Interface (CLI) for building React projects called "Create React App"; in this lesson, we show how to use this tool to quickly set up new projects using the `create-react-app {project-name}` command. We then use the npm scripts that are provided: `npm start` to develop, `npm run build` to ship, and `npm run eject` to opt out of the abstracted tooling.

The benefits of this tool are:
- It's officially maintained by the React team; this means best practices out of the box
- Zero config, one dependency
- Config is abstracted so React team can make improvements under the hood and you get the new goodness for free
- Clean command line output for errors
- You can "eject" at any time if needed

Set up React apps with zero configuration in two minutes

In this lesson we'll look at creating event listeners in our custom element using the listeners object as well as annotated event listeners.

Create Event Listeners in Polymer Elements

In this lesson we will examine two common scripts (start and test) that npm natively understands. We’ll define these scripts for our existing repository and show how you can run the scripts from the terminal.

Run the basic npm scripts

After creating several npm script it becomes useful to run multiple scripts back-to-back in series. This is a nice feature because you can enforce that one script needs to complete before starting another one.

Run npm scripts in series

In an effort to bypass saving temporary build files you can leverage piping and output redirection to streamline your build process. In addition using these technique can speed up your build process.

Pipe data from one npm script to another

In this lesson we will look about how we can integrate with git hooks to help enforce a certain level of quality before you either commit your code or push to a remote repository.

Run npm scripts with git hooks

There are times when it is helpful for a npm script to have lots of logs when trying to debug a problem, but there are other times when you want to run a script silently. Thankfully there are a range of flags to control the log level used when running npm scripts.

Change the level of console output when running npm scripts

In this lesson we will look at different ways you can list the available npm scripts. Whether we want to pipe `npm run` through `less` or install an npm package such as `completion` or `ntl`, we have many options to quickly execute scripts with shell tab completion.

List available npm scripts and support tab completion

A technique you might use once you start having lots of npm scripts is to use a node package that allows you to define your scripts in an external package-scripts.js file. By pulling out your scripts it can help with organization, enable better comments, provide shortcuts, and more.

Pull out npm scripts into another file with p-s

npm packages almost always have a git repo tied to them for version control. We will start our package by initializing a git repository.