HTML is global attribute
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
Note:Safari does not plan to support customized built-in elements andbrowser vendors are exploring alternative solutions to customizing built-ins. Check thebrowser compatibility section for support information.
Theisglobal attribute allows you to specify that a standard HTML element should behave like a defined customized built-in element (seeUsing custom elements for more details).
This attribute can only be used if the specified custom element name has been successfullydefined in the current document, and extends the element type it is being applied to.
Examples
The following code is taken from ourword-count-web-component example (see it live also).
js
// Create a class for the elementclass WordCount extends HTMLParagraphElement { constructor() { // Always call super first in constructor super(); // Constructor contents omitted for brevity // … }}// Define the new elementcustomElements.define("word-count", WordCount, { extends: "p" });html
<p is="word-count"></p>Specifications
| Specification |
|---|
| HTML # attr-is |