Acknowledgements

The beginning of your journey with Web Components.

Foreword

A brief introduction to the set of specifications called Web Components. We'll introduce you to concepts such as Shadow DOM, HTML templates, Custom Elements v1 and uncover typical use cases for developing Web Components.

Introduction to Web Components

We'll introduce you to the mockups in Figma, the development environment used throughout the book, and other conventions used in this book.

Conventions Used In The Book

A guide for installing various technologies needed prior to coding the exercises in this book.

Setting Up The Development Environment

We'll look at what you'll learn throughout Fullstack Web Components.

Module 1 Summary

Introduction

In Part 1, you'll code a form using several Web Components specifications.

Specification

Part One

By developing the CardComponent, you'll get hands on experience with autonomous custom elements.

Autonomous custom elements

Before you can develop the CardComponent, you'll need to scaffold the component in Storybook.

Template Slots

Shadow DOM provides encapsulation for styling and template. You'll style CardComponent with CSS in the context of the autonomous custom element's Shadow DOM.

Styling CardComponent

Write integration and snapshot tests for CardComponent using Cypress and Storybook Storyshots.

Testing the card

You built an autonomous custom element with Shadow DOM, HTML templates, and ES Modules. Let's reflect on that.

Chapter One Summary

Getting to Know Web Components

Form-associated custom elements allow custom elements to participate in HTML forms. From validation to submission, you'll code a text input end-to-end.

Form-associated custom elements

Scaffold a form-associated custom element named TextInputComponent in Storybook.

TextInputComponent

You'll learn what distinguises a form-associated custom element from an autonomous custom element, the formAssociated property and ElementInternals interface.

Form Associated and ElementInternals

Form-associated custom elements don't come with a pattern that validates an entire form, so you'll implement a pattern that allows form validation.

Handling Validation

Using observedAttributes and attributeChangedCallback to listen and react to changes in custom element attributes.

Listening for attribute changes

You'll style the various interaction states of the TextInputComponent form-associated custom element.

User feedback

We've created a problem by encapsulating the HTMLInputElement by Shadow DOM. The HTMLInputElement API cann't be accessed by the outside world. In this section, you'll fix that by implementing getters and setters that emulate the HTMLInputElement on TextInputComponent.

Emulating HTMLInputElement

You'll update the Story and provide the missing APIs to TextInputComponent that allow the component to fully interact with a HTML form.

Making a form

Reviewing the work completed on the form-associated custom element TextInputComponent.

Chapter Two Summary

You'll code ButtonComponent, a customized built-in element that inherits accessibility characteristics from HTMLButtonElement.

Customized built-in elements

Scaffold the customized built-in element ButtonComponent with Storybook.

Scaffolding ButtonComponent

Customized built-ins can't benefit from the encapsulation provided by Shadow DOM, so you'll have to find another way to style ButtonComponent.

Styling ButtonComponent

Revist the HTML form by making the user experience more accessible.

Making the form accessible

How customized built-in elements can make custom elements more accessible.

Chapter Three Summary

You'll learn best practices for developing a UI Library with Web Components by coding a micro-library, developing two custom elements with the micro-library, and figuring out how to package the UI library for distribution.

UI Library

Part Two

You'll abstract common patterns intro reusable code in a micro-library powered by TypeScript Decorators.

Micro-library

How to code an interface for Web Components with TypeScript decorators that enables declaration of the selector, styles, and template.

Class Decorator

You'll code a method decorator named Listen that binds event listeners to class methods.

Method Decorator

In this chapter you learned how to code a micro-library with TypeScript decorators that streamlines Web Component development.

Chapter Four Summary

You'll investigate multiple methods for components to communicate by coding an editable table.

Component Communication

How to use mock data in Storybook to code Web Components.

Mocking Table Data in Storybook

You'll learn about three methods for custom elements to communicate, attribute drilling, CustomEvent, and BroadcastChannel.

Coding Compound Components

You'll learn about how to create a separation of concerns between the many custom elements that comprise the editable table.

Making the Table Editable

You learned about how to create a separation of concerns between various custom elements in the same user experience flow.

Summary

Compound Custom Elements

You'll learn how to code a common UX pattern (dialogs) using HTML templates and custom elements.

HTML Templates

You'll mock the DialogComponent in Storybook.

Mocking the Dialog in Storybook

You'll make a configurable dialog with custom elements.

DialogComponent

You'll scaffold two custom elements that leverage DialogComponent to display modals and tooltips.

Modal and Tooltip

You'll fix an issue faced in the last section by learning how to query for elements across Shadow boundaries.

Querying DOM Across Shadow Boundaries

You'll control the ordering and event cycle of dialogs with a custom class named DialogStack.

DialogStack

Summarizing the work completed in DialogComponent, ModalComponent, TooltipComponent, and DialogStack.

Chapter Six Summary

Powering Dialogs with HTML Templates

You'll learn best practices for organizing and distributing Web Component UI libraries.

UI Libraries

You'll learn brest practices for distributing Web Components by formatting the code with named exports, configuring the build with Rollup, providing a standard package format, and writing a custom Node.js script that enables you to publish packages.

Distribution

Custom Elements Manifest provides a wealth of information about each component. After generating a manifest, it will provide documentation for each component in Storybook.

Documentation

You'll learn how to setup continuous integration for the UI library with Github Actions.

Continuous Integration

Let's reflect on the best practices you learned for distributing UI libraries filled with Web Components.

Chapter Seven Summary

Distributing Custom Element Libraries

You'll integrate the UI library with a single-page application and code the end-to-end user experience with custom elements.

Application

Part Three

You'll provide a separation of concerns with custom elements in a single page application.

Application Development with Custom Elements

You'll scaffold the landing page with an autonomous custom element named MainView.

Landing Page

You'll code a global header with autonomous custom elements named AppHeader.

Header

You'll code another autonomous custom element that handles cookie authorization named CookieFooter.

CookieFooter

You'll lazyload an image with customized built-ins.

Background

You developed the landing page of the application, learning how to architect a separation of concerns between the UI components.

Chapter Eight Summary

To handle multiple views in the single page application, you'll need to implement a router that can navigate between each view.

Routing Custom Elements in a SPA

You'll code the Router class that handles the creation and removal of views in the application.

Routing

You'll code the necessary components and services required in the login view.

Login View

Integrate TableCardComponent into a third view of the single page application, the dashboard.

Dashboard View

You coded a single page web application with custom elements and a custom router.

Chapter Nine Summary

You'll server-side render the views of the application with Declarative Shadow DOM and @lit-labs/ssr

Server-Side Rendering Custom Elements

You'll declare a server-side renderable Declarative Shadow DOM HTML template for each component.

Declarative Shadow DOM Templates

To get custom elements to work in Node.js, you'll need to polyfill DOM APIs. Luckily, @lit-labs/ssr provides a tool that enables just that.

Shim

You'll develop Express middleware that server-side renders Declarative Shadow DOM HTML Templates with @lit-labs/ssr.

Express Middleware

You rendered custom elements server-side using Declarative Shadow DOM and @lit-labs/ssr.

Chapter Ten Summary

Server-side Rendering with Declarative Shadow DOM

The conclusion of the book Fullstack Custom Elements.

Conclusion

Fullstack Web Components

Enter your name and email address below, then click the **"Send my free chapter"** button to get started

There are several books about Web Components, but none go into how to integrate Web Components in a typical enterprise web development workflow. This book is designed to help you learn Web Components and integrate it into your work.

In this book, we cover the basics of Web Components, how to code complex user interfaces with custom elements in Storybook, how to test and maintain UI libraries built with custom elements, and how to build web applications entirely with Web Components and browser specifications. It comes with complete code examples. We walk through the entire process step-by-step.

It's taught by Stephen Belovarich, a software engineer and web developer. Stephen has provided what he's learned about UI libraries and web applications while working at Ubiquiti Networks, Norton, Nike, NBC Universal, and Workday, that can benefit other developers, students, and anyone making a website.

The Complete Guide to Building UI Libraries with Web Components

In this book, we will learn Web Components through the lens of a JavaScript developer.

The basics of working with and manipulating Web Components

The best practices for maintaining a UI library made of custom elements

How to create a micro-library for Web Components with TypeScript Decorators

What problems Web Components can solve in everyday development

How to build web applications entirely from Web Components and JavaScript

Set up Continuous Integration with Github Actions

Right now, packages in the monorepo can only be built locally on a developer's computer. There's no way to build or test the UI library remotely, which could cause problems not only for other members of the development team, but those engineers who rely on the UI library for development. If an engineer checked in code to the main branch of the repo that couldn't be built, it may cause unwanted churn for others on the team. Anyone who wants to reference the documentation would have to clone the repository and build it locally. Continuous integration (CI) is a software development practice that automates the process of running builds, validating code against tests, and deploying resources like packages or servers. CI is beneficial for UI libraries because it provides transparency and insight into the development cycle of the library, while maintaining quality and consistency.

There are many tools available for Continuous Integration, but we're going to focus on getting CI up and running for the UI library using Github Actions. You already check in code to a repository hosted on Github for the purposes of completing this book, so it makes sense to use the tool that is native to the Github platform. Github Actions automates software development workflows whenever an engineer pushes code to a branch in Github. The process can be visualized in pull requests. When an engineer pushes up new commits to a branch associated with a pull request, Github Actions start whatever workflow is run 

, "a human-friendly data serialization language for all programming languages" according to the yaml.org. A single Github Actions workflow has a name, is performed on an event, and can run several jobs. Jobs have steps that run in parallel or sequentially. 

A complete guide for Github Actions is available here

In this section you'll write YAML to configure four Github Actions workflows:

If you're not familiar with YAML, don't worry. A walkthrough for setting up each Github Action is provided along with step-by-step instructions. To validate the Github Actions workflows are working correctly, you'll need to make changes to each 

 file, commit the changes and push up the branch to your fork of the 

 repository. Open a pull request to merge your branch into the main branch of the forked repo. You should be able to observe Github Actions workflows run on the last commit message in the PR.

Click on the icon in the last commit to view the current status of the workflow. When a pull request is merged to the main branch, an icon appears there as well to display the status of Github Actions workflows associated with pushing to the main branch.

When clicking on details of any Github Actions workflow, you should be able to observe the output of the jobs in that workflow.

The first Github Actions workflow you'll configure is the build. To start on this workflow, make a new directory named 

 in the root directory of the monorepo, making sure to preface the directory name with 

 directory, make another directory named 

. All the Github Actions workflows will be saved in this directory.

 in your favorite IDE to begin configuring the build Github Actions workflow. Start by specifying the name of the workflow: 

. YAML is written in succinct key/value pairs separated by a colon. On the second line of the 

 file, declare the events this workflow should run: 

, meaning whenever new commits are pushed to any remote branch.

 that should run on this workflow. There is only one job: 

 needs to run on a remote server. The latest Ubuntu linux distribution should work. Declare the 

, which automates the process of checking out a commit and running the job. Ubuntu doesn't come with NodeJS installed, so you need to also specify to install 

. After the installation is completed, it's safe to 

 which installs all project dependencies and 

 which calls on lerna to build every package in the monorepo.

---
title: Continuous Integration
description: You'll learn how to setup continuous integration for the UI library with Github Actions.
isPublicLesson: true
---

## Set up Continuous Integration with Github Actions

Right now, packages in the monorepo can only be built locally on a developer's computer. There's no way to build or test the UI library remotely, which could cause problems not only for other members of the development team, but those engineers who rely on the UI library for development. If an engineer checked in code to the main branch of the repo that couldn't be built, it may cause unwanted churn for others on the team. Anyone who wants to reference the documentation would have to clone the repository and build it locally. Continuous integration (CI) is a software development practice that automates the process of running builds, validating code against tests, and deploying resources like packages or servers. CI is beneficial for UI libraries because it provides transparency and insight into the development cycle of the library, while maintaining quality and consistency.

There are many tools available for Continuous Integration, but we're going to focus on getting CI up and running for the UI library using Github Actions. You already check in code to a repository hosted on Github for the purposes of completing this book, so it makes sense to use the tool that is native to the Github platform. Github Actions automates software development workflows whenever an engineer pushes code to a branch in Github. The process can be visualized in pull requests. When an engineer pushes up new commits to a branch associated with a pull request, Github Actions start whatever workflow is run `on: [push]`.

Github Actions are configured using [YAML](https://yaml.org), "a human-friendly data serialization language for all programming languages" according to the yaml.org. A single Github Actions workflow has a name, is performed on an event, and can run several jobs. Jobs have steps that run in parallel or sequentially. [A complete guide for Github Actions is available here](https://docs.github.com/en/actions/learn-github-actions).

In this section you'll write YAML to configure four Github Actions workflows:

-   Build validates that all packages in the monorepo can be built without error (on push)
-   Test runs integration tests (on push)
-   Snapshot runs snapshot tests (on push)
-   Storybook builds and deploys Storybook to Github Pages (on push in main branch only)

If you're not familiar with YAML, don't worry. A walkthrough for setting up each Github Action is provided along with step-by-step instructions. To validate the Github Actions workflows are working correctly, you'll need to make changes to each `.yaml` file, commit the changes and push up the branch to your fork of the `fullstack-web-components` repository. Open a pull request to merge your branch into the main branch of the forked repo. You should be able to observe Github Actions workflows run on the last commit message in the PR.

Click on the icon in the last commit to view the current status of the workflow. When a pull request is merged to the main branch, an icon appears there as well to display the status of Github Actions workflows associated with pushing to the main branch.

![](https://d2uusema5elisf.cloudfront.net/courses/fullstack-web-components/module_10/lesson_10.04/public/assets/all-workflows.png)

When clicking on details of any Github Actions workflow, you should be able to observe the output of the jobs in that workflow.

![](https://d2uusema5elisf.cloudfront.net/courses/fullstack-web-components/module_10/lesson_10.04/public/assets/github-actions.png)

### Build

The first Github Actions workflow you'll configure is the build. To start on this workflow, make a new directory named `.github` in the root directory of the monorepo, making sure to preface the directory name with `.` which infers the directory is hidden.

```bash
mkdir .github
```

Inside of the `.github` directory, make another directory named `workflows`. All the Github Actions workflows will be saved in this directory.

```bash
mkdir .github/workflows
```

Make a new YAML file named `build.yml` in `.github/workflows`.

```bash
touch .github/workflows/build.yml
```

Open `build.yml` in your favorite IDE to begin configuring the build Github Actions workflow. Start by specifying the name of the workflow: `build`. YAML is written in succinct key/value pairs separated by a colon. On the second line of the `build.yml` file, declare the events this workflow should run: `on: [push]`, meaning whenever new commits are pushed to any remote branch.

```yaml
name: build
on: [push]
```

Next, specify the `jobs` that should run on this workflow. There is only one job: `build` which is declared as a key on `jobs`. The `build` needs to run on a remote server. The latest Ubuntu linux distribution should work. Declare the `steps` of the job. Each step should use the `actions/checkout@v2`, which automates the process of checking out a commit and running the job. Ubuntu doesn't come with NodeJS installed, so you need to also specify to install `node` and `yarn`. After the installation is completed, it's safe to `run` two scripts in the monorepo: `yarn install` which installs all project dependencies and `yarn build` which calls on lerna to build every package in the monorepo.

```yaml
jobs:
	build:
		runs-on: ubuntu-latest
		steps:
		  - uses: actions/checkout@v2
		  - name: Install node
			uses: actions/setup-node@v2
			with:
			  node-version: "16"
			  cache: "yarn"
		  - run: yarn install
		  - run: yarn build
```

When you are done, the workflow should appear as follows:

```yaml
name: build
on: [push]
jobs:
	build:
		runs-on: ubuntu-latest
		steps:
		  - uses: actions/checkout@v2
		  - name: Install node
			uses: actions/setup-node@v2
			with:
			  node-version: "16"
			  cache: "yarn"
		  - run: yarn install
		  - run: yarn build
```