CustomElementRegistry: upgrade() method
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since January 2020.
The upgrade() method of the CustomElementRegistry interface upgrades all shadow-containing custom elements in a Node subtree, even before they are connected to the main document.
Syntax
js
upgrade(root) Parameters
Return value
None (undefined).
Examples
Taken from the HTML spec:
js
const el = document.createElement("spider-man"); class SpiderMan extends HTMLElement {} customElements.define("spider-man", SpiderMan); console.assert(!(el instanceof SpiderMan)); // not yet upgraded customElements.upgrade(el); console.assert(el instanceof SpiderMan); // upgraded! Specifications
| Specification |
|---|
| HTML # dom-customelementregistry-upgrade-dev |