Web components provide a powerful way to create reusable and encapsulated elements for web development. In this post, we will explore the process of creating custom elements using web components and dive into the concepts of the shadow DOM, lifecycle of a custom element, and defining behavior.

Shadow DOM: The shadow DOM is an essential part of web components, enabling encapsulation and separation of styling within elements. With the shadow DOM, we can create styles that only apply to specific components, preventing them from leaking and affecting other parts of the application.

To attach a shadow DOM to a custom element, we use the attachShadow method available on the Element prototype. For example, to create a custom element with a shadow DOM, we can define a class that extends the HTMLElement class and attach a shadow DOM to it:

class MyCustomElement extends HTMLElement {
  constructor() {
    super();
    const shadowRoot = this.attachShadow({ mode: 'open' });
    // Add content to the shadow DOM
  }
}