CustomElementRegistry.define

The define() method of the CustomElementRegistry interface defines a new custom element.

Syntax

customElements.define(name,constructor,options);

Parameters

name

Name for the new custom element.

constructor

Constructor for the new custom element.

options Optional

Object that controls how the element is defined. One option is currently supported:

• extends. String specifying the name of a built-in element to extend. Used to create a customized built-in element.

Return value

Void.

Examples

class BasicElement extends HTMLElement {
  connectedCallback() {
    this.textContent = 'Just a basic custom element.';
  }
}
customElements.define('basic-element', BasicElement);

<basic-element><basic-element>

Browser compatibility