CustomElementRegistry

The CustomElementRegistry interface provides methods for registering custom elements and querying registered elements. To get an instance of it, use the window.customElements property.

Instance methods

CustomElementRegistry.define(): Defines a new custom element.
CustomElementRegistry.get(): Returns the constructor for the named custom element, or undefined if the custom element is not defined.
CustomElementRegistry.getName(): Returns the name for the already-defined custom element, or null if the custom element is not defined.
CustomElementRegistry.upgrade(): Upgrades a custom element directly, even before it is connected to its shadow root.
CustomElementRegistry.whenDefined(): Returns an empty Promise that resolves when a custom element becomes defined with the given name. If such a custom element is already defined, the returned promise is immediately fulfilled.

Examples

See the Examples section in our guide to using custom elements.

Specifications

Specification
HTML Standard # custom-elements-api

Browser compatibility

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