ariaActionsElements

syntax

Verbatim from Chromium's aria_relationship_attributes.idl (the AriaRelationshipAttributes mixin, included by Element and ElementInternals):

[
    RuntimeEnabled=AOMAriaRelationshipProperties
] interface mixin AriaRelationshipAttributes {
    [CEReactions, Measure, RuntimeEnabled=AriaActions]
        attribute FrozenArray<Element>? ariaActionsElements;
    // ... ariaActiveDescendantElement, ariaControlsElements, etc.
};

Element includes AriaRelationshipAttributes;
ElementInternals includes AriaRelationshipAttributes;

Both flags are stable in shipping Chrome: AOMAriaRelationshipProperties (the mixin) is status: "stable" and AriaActions (the member) is {"Win": "stable", "Mac": "stable", "Linux": "stable"} — see the runtime flag record.

inputs (setter)

The setter accepts an array of Element references, an empty array, or null (per the WPT IDL-reflection tests):

outputs (getter)

The getter returns null by default, otherwise a FrozenArray of the currently resolvable target Elements, in assignment order. Repeated reads return the same FrozenArray instance until reassignment or a DOM change that alters resolution (see lifecycle). Reading after setting the content attribute with resolvable IDREFs returns those elements; unresolvable IDREFs reflect as an empty list ([]), not null.

errors and edge cases

context and exposure

Exposed on Element in window contexts and on ElementInternals for custom elements (the mixin is included by both interfaces). Gated by RuntimeEnabled=AriaActions: enabled by default in Chrome 151 on Windows, macOS, and Linux; not implemented on ChromeOS or Android (the Android key is omitted from the flag record, which disables it on both Chrome for Android and Android WebView). The mixin itself is gated by AOMAriaRelationshipProperties, stable on all platforms. Feature-detect with 'ariaActionsElements' in Element.prototype before use.

ElementInternals and custom elements

On ElementInternals (obtained via this.attachInternals() inside a custom element), the member behaves identically — the WPT suite runs the full shared test set against both Element and ElementInternals reflectors. This is the path for component authors: a custom tab element can set this.internals_.ariaActionsElements = [closeButton] so the action relationship is part of the component's encapsulated accessibility semantics rather than light-DOM markup.

class ActionTab extends HTMLElement {
  #internals = this.attachInternals();
  connectedCallback() {
    this.#internals.role = 'tab';
    const close = this.querySelector('button[aria-label]');
    if (close && 'ariaActionsElements' in this.#internals) {
      this.#internals.ariaActionsElements = [close];
    }
  }
}

lifecycle and state transitions

The reflection has precise, tested state semantics (all from the WPT suite):

examples

const tab = document.querySelector('[role="tab"]');
const closeBtn = tab.querySelector('.close');

// Feature-detect: member is absent on ChromeOS/Android and older browsers.
if ('ariaActionsElements' in tab) {
  tab.ariaActionsElements = [closeBtn];
} else {
  // Fallback: ID-reference form of the content attribute.
  closeBtn.id = closeBtn.id || 'close-tab-1';
  tab.setAttribute('aria-actions', closeBtn.id);
}

// Read back the effective targets (order preserved, disconnected
// targets filtered out).
console.log(tab.ariaActionsElements); // FrozenArray [button.close]

// Unset entirely (removes the content attribute).
tab.ariaActionsElements = null;

A full light-DOM markup example (tab strip with per-tab close actions) is on the feature overview, and live demos are on the Chrome Platform Showcase.

compatibility

No BCD entry exists for ariaActionsElements (checked api/Element, api/ElementInternals, and api/_mixins/ARIAMixin paths, 2026-07-28); interim table from the linked primary sources:

security and privacy

The member is a discovery-only accessibility bridge: it exposes references between elements that already exist in the DOM to assistive technologies, with no new script-observable capability beyond reading back what was set (the Measure extended attribute in the IDL only records a use counter). Cross-shadow-tree filtering prevents a document from probing or binding actions into closed component internals it does not own. The content attribute and IDL carry no personally identifying information beyond the accessible names authors already publish; the author obligation that targets be keyboard-operable (ARIA PR #1805 preview) is an accessibility safety requirement, not a security control.

references

• gendn — aria-actions feature overview
• Chromium aria_relationship_attributes.idl (verbatim IDL)
• WPT — idl-reflection.tentative.html (semantics source) · wpt.fyi results
• w3c/aria PR #1805 (ARIA preview)
• chromestatus.com/feature/5161589307867136