The CustomElementRegistry interface provides methods for registering custom elements and querying registered elements. To get an instance of it, use the window.customElements property. To create a scoped registry, use the CustomElementRegistry() constructor.
CustomElementRegistry()Creates a new CustomElementRegistry object, for scoped usage.
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.initialize()Associates a scoped registry with a DOM subtree, setting the custom element registry on each inclusive descendant and upgrading any custom elements.
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.
See the Examples section in our guide to using custom elements.