ElementInternals: ariaMultiLine property

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since October 2023.

The ariaMultiLine property of the ElementInternals interface reflects the value of the aria-multiline attribute, which indicates whether a text box accepts multiple lines of input or only a single line.

Note: Setting aria attributes on ElementInternals allows default semantics to be defined on a custom element. These may be overwritten by author-defined attributes, but ensure that default semantics are retained should the author delete those attributes, or fail to add them at all. For more information see the Accessibility Object Model explainer.

Value

A string with one of the following values:

"true": This is a multi-line text box.
"false": This is a single-line text box.

Examples

In this example the value of ariaMultiLine is set to "true".

class CustomControl extends HTMLElement {
  constructor() {
    super();
    this.internals_ = this.attachInternals();
    this.internals_.ariaMultiLine = "true";
  }
  // …
}