web api instance property
Element: customElementRegistry property
The customElementRegistry read-only property of the Element interface returns the CustomElementRegistry object associated with this element, or null if one has not been set.
An element’s customElementRegistry is set when the element is created (for example, via createElement() with the customElementRegistry option, or when parsed in a context that has a scoped registry). Once set to a CustomElementRegistry object, it cannot be changed. The registry determines which custom element definitions are used when the element is upgraded.
Value
A CustomElementRegistry object, or null.
Examples
Accessing an element’s custom element registry
This example creates a scoped registry, attaches it to a shadow root, and then reads back the customElementRegistry property from an element inside the shadow tree to confirm it matches the scoped registry.
const myRegistry = new CustomElementRegistry();
myRegistry.define(
"my-element",
class extends HTMLElement {
connectedCallback() {
this.textContent = "Hello from scoped registry!";
}
},
);
const host = document.createElement("div");
document.body.appendChild(host);
const shadow = host.attachShadow({
mode: "open",
customElementRegistry: myRegistry,
});
shadow.innerHTML = "<my-element></my-element>";
const el = shadow.querySelector("my-element");
console.log(el.customElementRegistry === myRegistry); // true