What are Web Components?

Web Components are a set of standards that allow the creation of user interface components without relying on external libraries. They consist of custom elements, shadow DOM, and HTML templates. These technologies will enable the creation of universal components that work natively in browsers, meaning they can be used independently of libraries such as React, Vue, or Angular. As a result, web components offer greater flexibility and interoperability between different frameworks, limited only by the browser’s support for these standards

Web Components Technologies

The following technologies enable developers to create complex user interfaces with high modularity and compatibility. These tools allow developers to create more personalized, efficient, and functional Web applications.

Custom Elements

Custom elements are JavaScript APIs allowing you to create and manage your DOM elements. They allow you to extend existing HTML tags or create entirely new ones, greatly enhancing the customization of user interfaces.

Shadow DOM

Shadow DOM introduces the concept of encapsulation to the DOM, meaning that DOM elements and their styles can be isolated from the rest of the page. This allows each component to have its own independent environment without the risk of interference from external styles or scripts.

HTML templates

The <template> element allows you to define snippets of HTML code that are inactive until needed. This allows code to be reused efficiently without slowing down the page’s performance, which is crucial for large projects.

How do I create a simple component using this technology? See below for a quick guide

Step 1: Define the component class

First, define a component class that extends HTMLElement, which is a native class for HTML elements. In this class, you will define all the functionality of your component.

class MyComponent extends HTMLElement {
  constructor() {
    super(); // always call superconstructor
    this.attachShadow({ mode: 'open' }); // add shadow DOM

Step 2: Adding Shadow DOM

The Shadow DOM allows you to isolate the CSS and HTML in the component, so the styles don’t affect the rest of the page.

class MyComponent extends HTMLElement {
  constructor() {
    this.attachShadow({ mode: 'open' });
    this.shadowRoot.innerHTML = `.
        p {
          color: blue;
      <p>Hello from My Component!</p>

Step 3: Registering your component

After defining the class, you need to register your component to use the new tag in HTML. Use the customElements.define() method.

customElements.define('my-component', MyComponent);

Step 4: Use the component
Once registered, you can use your component like any other HTML element by adding it to your page.


Why use Web Components – Advantages

Web components offer many advantages that make them an attractive choice for web developers:

Isolation: Thanks to the shadow DOM, each component’s styles and scripts are isolated from the rest of the page, eliminating conflict and overwrite issues and increasing application stability.

Efficiency: Using <template> elements allows content to be loaded only when needed, improving page performance.

Interoperability with other systems: Components can be used independently of the frameworks and libraries, making them easy to integrate with different technologies.

Customization: Custom elements allow the creation of personalized HTML elements, enhancing user interfaces’ interactive and visual capabilities.

FAQ – Frequently Asked Questions

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