Document.registerElement()

The document.registerElement() method registers a new custom element in the browser and returns a constructor for the new element.

Syntax

var constructor = document.registerElement(tag-name, options);

Parameters

tag-name

The name of the custom element. The name must contain a dash (-), for example my-tag.

options Optional

An object with properties prototype to base the custom element on, and extends, an existing tag to extend. Both of these are optional.

Example

Here is a very simple example:

var Mytag = document.registerElement('my-tag');

Now the new tag is registered in the browser. The Mytag variable holds a constructor that you can use to create a my-tag element in the document as follows:

document.body.appendChild(new Mytag());

This inserts an empty my-tag element that will be visible if you use the browser's developer tools. It will not be visible if you use the browser's view source capability. And it won't be visible in the browser unless you add some content to the tag. Here is one way to add content to the new tag:

var mytag = document.getElementsByTagName("my-tag")[0];
mytag.textContent = "I am a my-tag element.";

Specifications

Browser compatibility

[1] This API is implemented behind a preference.

See Also

• Custom Elements