feat: add ARIA attributes to popover overlay and target

packages/popover/src/vaadin-popover.d.ts

@@ -38,6 +38,20 @@ export type PopoverEventMap = HTMLElementEventMap & PopoverCustomEventMap;
 declare class Popover extends PopoverPositionMixin(
   PopoverTargetMixin(OverlayClassMixin(ThemePropertyMixin(ElementMixin(HTMLElement)))),
 ) {
+  /**
+   * String used to label the overlay to screen reader users.
+   *
+   * @attr {string} accessible-name
+   */
+  accessibleName: string | null | undefined;
+
+  /**
+   * Id of the element used as label of the overlay to screen reader users.
+   *
+   * @attr {string} accessible-name-ref
+   */
+  accessibleNameRef: string | null | undefined;
+
   /**
    * Height to be set on the overlay content.
    *
@@ -57,6 +71,13 @@ declare class Popover extends PopoverPositionMixin(
    */
   opened: boolean;
 
+  /**
+   * The `role` attribute value to be set on the overlay.
+   *
+   * @attr {string} overlay-role
+   */
+  overlayRole: string;
+
   /**
    * Custom function for rendering the content of the overlay.
    * Receives two arguments:

packages/popover/src/vaadin-popover.js

@@ -11,6 +11,7 @@ import { defineCustomElement } from '@vaadin/component-base/src/define.js';
 import { ElementMixin } from '@vaadin/component-base/src/element-mixin.js';
 import { OverlayClassMixin } from '@vaadin/component-base/src/overlay-class-mixin.js';
 import { PolylitMixin } from '@vaadin/component-base/src/polylit-mixin.js';
+import { generateUniqueId } from '@vaadin/component-base/src/unique-id-utils.js';
 import { ThemePropertyMixin } from '@vaadin/vaadin-themable-mixin/vaadin-theme-property-mixin.js';
 import { PopoverPositionMixin } from './vaadin-popover-position-mixin.js';
 import { PopoverTargetMixin } from './vaadin-popover-target-mixin.js';
@@ -41,6 +42,24 @@ class Popover extends PopoverPositionMixin(
 
   static get properties() {
     return {
+      /**
+       * String used to label the overlay to screen reader users.
+       *
+       * @attr {string} accessible-name
+       */
+      accessibleName: {
+        type: String,
+      },
+
+      /**
+       * Id of the element used as label of the overlay to screen reader users.
+       *
+       * @attr {string} accessible-name-ref
+       */
+      accessibleNameRef: {
+        type: String,
+      },
+
       /**
        * Height to be set on the overlay content.
        *
@@ -69,6 +88,16 @@ class Popover extends PopoverPositionMixin(
         observer: '__openedChanged',
       },
 
+      /**
+       * The `role` attribute value to be set on the overlay.
+       *
+       * @attr {string} overlay-role
+       */
+      overlayRole: {
+        type: String,
+        value: 'dialog',
+      },
+
       /**
        * Custom function for rendering the content of the overlay.
        * Receives two arguments:
@@ -153,18 +182,28 @@ class Popover extends PopoverPositionMixin(
         value: false,
         sync: true,
       },
+
+      /** @private */
+      __overlayId: {
+        type: String,
+      },
     };
   }
 
   static get observers() {
     return [
       '__updateContentHeight(contentHeight, _overlayElement)',
       '__updateContentWidth(contentWidth, _overlayElement)',
+      '__openedOrTargetChanged(opened, target)',
+      '__overlayRoleOrTargetChanged(overlayRole, target)',
     ];
   }
 
   constructor() {
     super();
+
+    this.__overlayId = `vaadin-popover-${generateUniqueId()}`;
+
     this.__onGlobalClick = this.__onGlobalClick.bind(this);
     this.__onGlobalKeyDown = this.__onGlobalKeyDown.bind(this);
     this.__onTargetClick = this.__onTargetClick.bind(this);
@@ -181,6 +220,10 @@ class Popover extends PopoverPositionMixin(
 
     return html`
       <vaadin-popover-overlay
+        id="${this.__overlayId}"
+        role="${this.overlayRole}"
+        aria-label="${ifDefined(this.accessibleName)}"
+        aria-labelledby="${ifDefined(this.accessibleNameRef)}"
         .renderer="${this.renderer}"
         .owner="${this}"
         theme="${ifDefined(this._theme)}"
@@ -282,6 +325,33 @@ class Popover extends PopoverPositionMixin(
     }
   }
 
+  /** @private */
+  __openedOrTargetChanged(opened, target) {
+    if (target) {
+      target.setAttribute('aria-expanded', opened ? 'true' : 'false');
+
+      if (opened) {
+        target.setAttribute('aria-controls', this.__overlayId);
+      } else {
+        target.removeAttribute('aria-controls');
+      }
+    }
+  }
+
+  /** @private */
+  __overlayRoleOrTargetChanged(overlayRole, target) {
+    if (this.__oldTarget) {
+      this.__oldTarget.removeAttribute('aria-haspopup');
+    }
+
+    if (target) {
+      const isDialog = overlayRole === 'dialog' || overlayRole === 'alertdialog';
+      target.setAttribute('aria-haspopup', isDialog ? 'dialog' : 'true');
+
+      this.__oldTarget = target;
+    }
+  }
+
   /**
    * Overlay's global outside click listener doesn't work when
    * the overlay is modeless, so we use a separate listener.

packages/popover/test/a11y.test.js

@@ -21,6 +21,111 @@ describe('a11y', () => {
     overlay = popover.shadowRoot.querySelector('vaadin-popover-overlay');
   });
 
+  describe('ARIA attributes', () => {
+    it('should set role attribute on the overlay to dialog', () => {
+      expect(overlay.getAttribute('role')).to.equal('dialog');
+    });
+
+    it('should change role attribute on the overlay based on overlayRole', async () => {
+      popover.overlayRole = 'alertdialog';
+      await nextUpdate(popover);
+      expect(overlay.getAttribute('role')).to.equal('alertdialog');
+    });
+
+    it('should set aria-haspopup attribute on the target', () => {
+      expect(target.getAttribute('aria-haspopup')).to.equal('dialog');
+    });
+
+    it('should keep aria-haspopup attribute when overlayRole is set to alertdialog', async () => {
+      popover.overlayRole = 'alertdialog';
+      await nextUpdate(popover);
+      expect(target.getAttribute('aria-haspopup')).to.equal('dialog');
+    });
+
+    it('should update aria-haspopup attribute when overlayRole is set to different value', async () => {
+      popover.overlayRole = 'menu';
+      await nextUpdate(popover);
+      expect(target.getAttribute('aria-haspopup')).to.equal('true');
+    });
+
+    it('should remove aria-haspopup attribute when target is cleared', async () => {
+      popover.target = null;
+      await nextUpdate(popover);
+      expect(target.hasAttribute('aria-haspopup')).to.be.false;
+    });
+
+    it('should remove aria-controls attribute when target is cleared', async () => {
+      popover.target = null;
+      await nextUpdate(popover);
+      expect(target.hasAttribute('aria-haspopup')).to.be.false;
+    });
+
+    it('should set aria-expanded attribute on the target when closed', () => {
+      expect(target.getAttribute('aria-expanded')).to.equal('false');
+    });
+
+    it('should set aria-expanded attribute on the target when opened', async () => {
+      popover.opened = true;
+      await nextRender();
+      expect(target.getAttribute('aria-expanded')).to.equal('true');
+    });
+
+    it('should set aria-controls attribute on the target when opened', async () => {
+      popover.opened = true;
+      await nextRender();
+      expect(target.getAttribute('aria-controls')).to.equal(overlay.id);
+    });
+
+    it('should remove aria-controls attribute from the target when closed', async () => {
+      popover.opened = true;
+      await nextRender();
+
+      popover.opened = false;
+      await nextUpdate(popover);
+      expect(target.hasAttribute('aria-controls')).to.be.false;
+    });
+  });
+
+  describe('accessible name', () => {
+    it('should not set aria-label on the overlay by default', () => {
+      expect(overlay.hasAttribute('aria-label')).to.be.false;
+    });
+
+    it('should set aria-label on the overlay when accessibleName is set', async () => {
+      popover.accessibleName = 'Label text';
+      await nextUpdate(popover);
+      expect(overlay.getAttribute('aria-label')).to.equal('Label text');
+    });
+
+    it('should remove aria-label on the overlay when accessibleName is removed', async () => {
+      popover.accessibleName = 'Label text';
+      await nextUpdate(popover);
+
+      popover.accessibleName = null;
+      await nextUpdate(popover);
+      expect(overlay.hasAttribute('aria-label')).to.be.false;
+    });
+
+    it('should not set aria-labelledby on the overlay by default', () => {
+      expect(overlay.hasAttribute('aria-labelledby')).to.be.false;
+    });
+
+    it('should set aria-labelledby on the overlay when accessibleName is set', async () => {
+      popover.accessibleNameRef = 'custom-label';
+      await nextUpdate(popover);
+      expect(overlay.getAttribute('aria-labelledby')).to.equal('custom-label');
+    });
+
+    it('should remove aria-label on the overlay when accessibleName is removed', async () => {
+      popover.accessibleNameRef = 'custom-label';
+      await nextUpdate(popover);
+
+      popover.accessibleNameRef = null;
+      await nextUpdate(popover);
+      expect(overlay.hasAttribute('aria-labelledby')).to.be.false;
+    });
+  });
+
   describe('focus restoration', () => {
     describe('focus trigger', () => {
       beforeEach(async () => {

packages/popover/test/typings/popover.types.ts

@@ -28,9 +28,12 @@ assertType<HTMLElement | undefined>(popover.target);
 assertType<PopoverPosition>(popover.position);
 assertType<PopoverRenderer | null | undefined>(popover.renderer);
 assertType<PopoverTrigger[] | null | undefined>(popover.trigger);
+assertType<string | null | undefined>(popover.accessibleName);
+assertType<string | null | undefined>(popover.accessibleNameRef);
 assertType<string>(popover.contentHeight);
 assertType<string>(popover.contentWidth);
 assertType<string>(popover.overlayClass);
+assertType<string>(popover.overlayRole);
 assertType<boolean>(popover.opened);
 assertType<boolean>(popover.modal);
 assertType<boolean>(popover.withBackdrop);