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

The decisions we've made have so far developing the login form resulted in a half-baked accessible experience for users who rely on the keyboard to navigate. 

 has some accessibility limitations. We've provided a CSS classname to provide visual feedback, but this poses a problem for the visually impaired, who cannot observe the feedback when the input becomes invalid. Furthermore, validations appended to Shadow DOM cannot be accessed by screen readers unless we provide some additional context using WAI-ARIA.

 is useable via keyboard input by virtue of extending from 

, the addition of an SVG in the icon variant prohibits visually impaired users from understanding the context of the button element. Screen readers rely on the content of the button to provide a label, which the primary and secondary button variants handle already. The icon variant lacks a text label that screen readers can analyze and read aloud to the user.

In this section, you'll use WAI-ARIA attributes to solve two distinct problems with the form:

 as your development environment. After a brief introduction to using a screen reader during development, you'll use WAI-ARIA attributes to provide all the necessary context the screen reader requires to aid in navigating the form.

 in isolation, so let's see what happens when you integrate the component into the existing Form story in 

import { ButtonComponent } from "../button/Button";

 so that the browser can interpret the buttons as a customized built-in element. Add the appropriate classnames to the submit button. According to Figma, the submit button is a primary variant of the 

        <button class="primary" is="in-button" type="submit">Submit</button>

 is a customized built-in element, integration was a snap. The elements in the layout appear very close vertically and don't have the same margin between them as the mockup in Figma. To fix this issue with the layout, add a global style to 

.form-control {
  margin-bottom: var(--margin-md);
}

For the remainder of this chapter, use the 

 stories as a test bed for providing accessibility features to 

Screen readers are applications that blind, visually impaired, and dyslexic people use to interact with operating systems. Through the use of a synthesized voice and other visual cues, screen readers provide contextual information about what the user currently has focused in a user interface. NVDA is the most popular screen reader application for Windows, while VoiceOver is built into MacOS and other Apple operating systems.

If you've never used a screen reader application before, follow the steps below to install and open NVDA or VoiceOver for Windows and MacOS, respectively.

NVDA, short for NonVisual Desktop Access, is a Windows application available for free on the Microsoft Store. To install NVDA, sign in to the Microsoft Store in the Microsoft Store application.

After you have signed in to the Microsoft Store, search for NVDA, select the application in the search results, and click the 

 button. Follow on-screen prompts to install NVDA.

Once NVDA is installed, access NVDA application preferences in the Windows Taskbar.

NVDA uses a synthesized voice to announce contextual information about the currently focused user interface for visually impaired and blind users in Microsoft Windows.

To stop NVDA at any time, click the NVDA icon in the Windows Taskbar and choose 

VoiceOver is a screen reader provided by Apple Inc. in all of its operating systems. In MacOS, access VoiceOver in the System Preferences Accessibility Pane. When you click 

, a contextual overlay appears in the lower left of the screen. VoiceOver announces what is currently in focus through a synthesized voice.

---
title: Making the form accessible
description: Revist the HTML form by making the user experience more accessible.
isPublicLesson: true
---

## Making the form accessible

The decisions we've made have so far developing the login form resulted in a half-baked accessible experience for users who rely on the keyboard to navigate. `TextInputComponent` has some accessibility limitations. We've provided a CSS classname to provide visual feedback, but this poses a problem for the visually impaired, who cannot observe the feedback when the input becomes invalid. Furthermore, validations appended to Shadow DOM cannot be accessed by screen readers unless we provide some additional context using WAI-ARIA.

While `ButtonComponent` is useable via keyboard input by virtue of extending from `HTMLButtonElement`, the addition of an SVG in the icon variant prohibits visually impaired users from understanding the context of the button element. Screen readers rely on the content of the button to provide a label, which the primary and secondary button variants handle already. The icon variant lacks a text label that screen readers can analyze and read aloud to the user.

In this section, you'll use WAI-ARIA attributes to solve two distinct problems with the form:

-   Screen readers cannot analyze the button label in the icon variant
-   Screen readers cannot read the validation messages so that users who rely on screen readers can understand what is needed to validate each form field

First, you'll add `ButtonComponent` to the `Form` story in `TextInput.stories.js` so that you can use `FormTemplate` as your development environment. After a brief introduction to using a screen reader during development, you'll use WAI-ARIA attributes to provide all the necessary context the screen reader requires to aid in navigating the form.

### Button Form

In this chapter, you've developed `ButtonComponent` in isolation, so let's see what happens when you integrate the component into the existing Form story in `TextInput.stories.js`.

Import `ButtonComponent` into `TextInput.stories.js`.

```javascript { actualFilename=./protected/src/TextInput.stories.js endLine=3 startLine=3 statedFilename=TextInput.stories.js url=https&#x3A;//gitlab.com/fullstackio/books/fullstack-web-components/module_05/lesson_05.04/protected/src/TextInput.stories.js#L3 }
import { ButtonComponent } from "../button/Button";
```

Swap out the `input type="submit"` in `FormTemplate` for the `button`. Set the `is` attribute to `in-button` on the button element in `FormTemplate` so that the browser can interpret the buttons as a customized built-in element. Add the appropriate classnames to the submit button. According to Figma, the submit button is a primary variant of the `ButtonComponent`.

```javascript { actualFilename=./protected/src/TextInput.stories.js endLine=156 startLine=156 statedFilename=TextInput.stories.js url=https&#x3A;//gitlab.com/fullstackio/books/fullstack-web-components/module_05/lesson_05.04/protected/src/TextInput.stories.js#L156 }
        <button class="primary" is="in-button" type="submit">Submit</button>
```

That's it! Since `ButtonComponent` is a customized built-in element, integration was a snap. The elements in the layout appear very close vertically and don't have the same margin between them as the mockup in Figma. To fix this issue with the layout, add a global style to `packages/style/style.css`. Select each instance of `TextInputComponent` with a CSS classname: `.form-control` and set `margin-bottom`.

```css
.form-control {
  margin-bottom: var(--margin-md);
}
```

For the remainder of this chapter, use the `Form` and `Icon` stories as a test bed for providing accessibility features to `ButtonComponent` and `TextInputComponent`.

### Using a screen reader

Screen readers are applications that blind, visually impaired, and dyslexic people use to interact with operating systems. Through the use of a synthesized voice and other visual cues, screen readers provide contextual information about what the user currently has focused in a user interface. NVDA is the most popular screen reader application for Windows, while VoiceOver is built into MacOS and other Apple operating systems.

If you've never used a screen reader application before, follow the steps below to install and open NVDA or VoiceOver for Windows and MacOS, respectively.

#### Windows

NVDA, short for NonVisual Desktop Access, is a Windows application available for free on the Microsoft Store. To install NVDA, sign in to the Microsoft Store in the Microsoft Store application.

![](https://d2uusema5elisf.cloudfront.net/courses/fullstack-web-components/module_05/lesson_05.04/public/assets/nvda-microsoft-store.png)

After you have signed in to the Microsoft Store, search for NVDA, select the application in the search results, and click the **Install** button. Follow on-screen prompts to install NVDA.

Once NVDA is installed, access NVDA application preferences in the Windows Taskbar.

![](https://d2uusema5elisf.cloudfront.net/courses/fullstack-web-components/module_05/lesson_05.04/public/assets/nvda.png)

NVDA uses a synthesized voice to announce contextual information about the currently focused user interface for visually impaired and blind users in Microsoft Windows.

To stop NVDA at any time, click the NVDA icon in the Windows Taskbar and choose **Exit** from the dialog.

#### MacOS

VoiceOver is a screen reader provided by Apple Inc. in all of its operating systems. In MacOS, access VoiceOver in the System Preferences Accessibility Pane. When you click **Enable VoiceOver**, a contextual overlay appears in the lower left of the screen. VoiceOver announces what is currently in focus through a synthesized voice.

![](https://d2uusema5elisf.cloudfront.net/courses/fullstack-web-components/module_05/lesson_05.04/public/assets/voiceover.png)

During development, you may have to change context rapidly between IDE and browser. If the synthesized voice becomes a burden, you can turn it off by clicking **Open VoiceOver Utility...** in the System Preferences Accessibility Pane. When the VoiceOver Utility Pane appears, select **Speech** in the Sidebar, and click **Mute Speech**.

![](https://d2uusema5elisf.cloudfront.net/courses/fullstack-web-components/module_05/lesson_05.04/public/assets/voiceover-turn-off-voice.png)

Another option you may find useful during development is the ability to hide the VoiceOver cursor. In your IDE, the VoiceOver cursor displays an overlayed cursor for the visually impaired. However, this can interfere with typing for some users.

Once you have a screen reader installed, proceed to the following sections. If you've never used a screen reader before, hopefully you'll find a process for developing with a screen reader that works best for you.

### Providing context to the icon variant

Earlier in this chapter, you developed the icon variant of `ButtonComponent`. However, since the label is effectively replaced by an SVG, screen readers can no longer analyze the content of the button element.