fix(select): improve screen reader announcement timing for validation errors (#30723)

Issue number: internal

---------

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issue. -->

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etc). Submit multiple pull requests if needed. -->

## What is the current behavior?
<!-- Please describe the current behavior that you are modifying. -->

Currently, when an error text is shown, it may not announce itself to
voice assistants. This is because the way error text currently works is
by always existing in the DOM, but being hidden when there is no error.
When the error state changes, the error text is shown, but as far as the
voice assistant can tell it's always been there and nothing has changed.

## What is the new behavior?
<!-- Please describe the behavior or changes that are being added by
this PR. -->

- Updated aria attributes
- Added observer with an observer

We had to do this with a mutation observer and state because it's
important in some frameworks, like Angular, that state changes to cause
a re-render. This, combined with some minor aria changes, makes it so
that when a field is declared invalid, it immediately announces the
invalid state instead of waiting for the user to go back to the invalid
field.

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

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below.
  2. Update the BREAKING.md file with the breaking change.
3. Add "BREAKING CHANGE: [...]" to the commit description when merging.
See
https://github.com/ionic-team/ionic-framework/blob/main/docs/CONTRIBUTING.md#footer
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## Other information

<!-- Any other information that is important to this PR such as
screenshots of how the component looks before and after the change. -->


[Preview](https://ionic-framework-git-fw-6797-ionic1.vercel.app/src/components/select/test/validation/)

Author: thetaPC

core/src/components/input/input.tsx

@@ -14,7 +14,7 @@ import {
   h,
 } from '@stencil/core';
 import type { NotchController } from '@utils/forms';
-import { createNotchController } from '@utils/forms';
+import { createNotchController, checkInvalidState } from '@utils/forms';
 import type { Attributes } from '@utils/helpers';
 import { inheritAriaAttributes, debounceEvent, inheritAttributes, componentOnReady } from '@utils/helpers';
 import { createSlotMutationController } from '@utils/slot-mutation-controller';
@@ -403,16 +403,6 @@ export class Input implements ComponentInterface {
     };
   }
 
-  /**
-   * Checks if the input is in an invalid state based on Ionic validation classes
-   */
-  private checkInvalidState(): boolean {
-    const hasIonTouched = this.el.classList.contains('ion-touched');
-    const hasIonInvalid = this.el.classList.contains('ion-invalid');
-
-    return hasIonTouched && hasIonInvalid;
-  }
-
   connectedCallback() {
     const { el } = this;
 
@@ -426,7 +416,7 @@ export class Input implements ComponentInterface {
     // Watch for class changes to update validation state
     if (Build.isBrowser && typeof MutationObserver !== 'undefined') {
       this.validationObserver = new MutationObserver(() => {
-        const newIsInvalid = this.checkInvalidState();
+        const newIsInvalid = checkInvalidState(el);
         if (this.isInvalid !== newIsInvalid) {
           this.isInvalid = newIsInvalid;
           // Force a re-render to update aria-describedby immediately
@@ -441,7 +431,7 @@ export class Input implements ComponentInterface {
     }
 
     // Always set initial state
-    this.isInvalid = this.checkInvalidState();
+    this.isInvalid = checkInvalidState(el);
 
     this.debounceChanged();
     if (Build.isBrowser) {

core/src/components/select/select.tsx

@@ -1,7 +1,7 @@
 import type { ComponentInterface, EventEmitter } from '@stencil/core';
-import { Component, Element, Event, Host, Method, Prop, State, Watch, h, forceUpdate } from '@stencil/core';
+import { Build, Component, Element, Event, Host, Method, Prop, State, Watch, h, forceUpdate } from '@stencil/core';
 import type { NotchController } from '@utils/forms';
-import { compareOptions, createNotchController, isOptionSelected } from '@utils/forms';
+import { compareOptions, createNotchController, isOptionSelected, checkInvalidState } from '@utils/forms';
 import { focusVisibleElement, renderHiddenInput, inheritAttributes } from '@utils/helpers';
 import type { Attributes } from '@utils/helpers';
 import { printIonWarning } from '@utils/logging';
@@ -64,6 +64,7 @@ export class Select implements ComponentInterface {
   private inheritedAttributes: Attributes = {};
   private nativeWrapperEl: HTMLElement | undefined;
   private notchSpacerEl: HTMLElement | undefined;
+  private validationObserver?: MutationObserver;
 
   private notchController?: NotchController;
 
@@ -81,6 +82,13 @@ export class Select implements ComponentInterface {
    */
   @State() hasFocus = false;
 
+  /**
+   * Track validation state for proper aria-live announcements.
+   */
+  @State() isInvalid = false;
+
+  @State() private hintTextID?: string;
+
   /**
    * The text to display on the cancel button.
    */
@@ -298,10 +306,51 @@ export class Select implements ComponentInterface {
        */
       forceUpdate(this);
     });
+
+    // Watch for class changes to update validation state.
+    if (Build.isBrowser && typeof MutationObserver !== 'undefined') {
+      this.validationObserver = new MutationObserver(() => {
+        const newIsInvalid = checkInvalidState(this.el);
+        if (this.isInvalid !== newIsInvalid) {
+          this.isInvalid = newIsInvalid;
+          /**
+           * Screen readers tend to announce changes
+           * to `aria-describedby` when the attribute
+           * is changed during a blur event for a
+           * native form control.
+           * However, the announcement can be spotty
+           * when using a non-native form control
+           * and `forceUpdate()`.
+           * This is due to `forceUpdate()` internally
+           * rescheduling the DOM update to a lower
+           * priority queue regardless if it's called
+           * inside a Promise or not, thus causing
+           * the screen reader to potentially miss the
+           * change.
+           * By using a State variable inside a Promise,
+           * it guarantees a re-render immediately at
+           * a higher priority.
+           */
+          Promise.resolve().then(() => {
+            this.hintTextID = this.getHintTextID();
+          });
+        }
+      });
+
+      this.validationObserver.observe(el, {
+        attributes: true,
+        attributeFilter: ['class'],
+      });
+    }
+
+    // Always set initial state
+    this.isInvalid = checkInvalidState(this.el);
   }
 
   componentWillLoad() {
     this.inheritedAttributes = inheritAttributes(this.el, ['aria-label']);
+
+    this.hintTextID = this.getHintTextID();
   }
 
   componentDidLoad() {
@@ -328,6 +377,12 @@ export class Select implements ComponentInterface {
       this.notchController.destroy();
       this.notchController = undefined;
     }
+
+    // Clean up validation observer to prevent memory leaks.
+    if (this.validationObserver) {
+      this.validationObserver.disconnect();
+      this.validationObserver = undefined;
+    }
   }
 
   /**
@@ -1056,8 +1111,8 @@ export class Select implements ComponentInterface {
         aria-label={this.ariaLabel}
         aria-haspopup="dialog"
         aria-expanded={`${isExpanded}`}
-        aria-describedby={this.getHintTextID()}
-        aria-invalid={this.getHintTextID() === this.errorTextId}
+        aria-describedby={this.hintTextID}
+        aria-invalid={this.isInvalid ? 'true' : undefined}
         aria-required={`${required}`}
         onFocus={this.onFocus}
         onBlur={this.onBlur}
@@ -1067,9 +1122,9 @@ export class Select implements ComponentInterface {
   }
 
   private getHintTextID(): string | undefined {
-    const { el, helperText, errorText, helperTextId, errorTextId } = this;
+    const { helperText, errorText, helperTextId, errorTextId, isInvalid } = this;
 
-    if (el.classList.contains('ion-touched') && el.classList.contains('ion-invalid') && errorText) {
+    if (isInvalid && errorText) {
       return errorTextId;
     }
 
@@ -1084,14 +1139,14 @@ export class Select implements ComponentInterface {
    * Renders the helper text or error text values
    */
   private renderHintText() {
-    const { helperText, errorText, helperTextId, errorTextId } = this;
+    const { helperText, errorText, helperTextId, errorTextId, isInvalid } = this;
 
     return [
-      <div id={helperTextId} class="helper-text" part="supporting-text helper-text">
-        {helperText}
+      <div id={helperTextId} class="helper-text" part="supporting-text helper-text" aria-live="polite">
+        {!isInvalid ? helperText : null}
       </div>,
-      <div id={errorTextId} class="error-text" part="supporting-text error-text">
-        {errorText}
+      <div id={errorTextId} class="error-text" part="supporting-text error-text" role="alert">
+        {isInvalid ? errorText : null}
       </div>,
     ];
   }

core/src/components/select/test/validation/index.html

@@ -0,0 +1,200 @@
+<!DOCTYPE html>
+<html lang="en" dir="ltr">
+  <head>
+    <meta charset="UTF-8" />
+    <title>Select - Validation</title>
+    <meta
+      name="viewport"
+      content="viewport-fit=cover, width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no"
+    />
+    <link href="../../../../../css/ionic.bundle.css" rel="stylesheet" />
+    <link href="../../../../../scripts/testing/styles.css" rel="stylesheet" />
+    <script src="../../../../../scripts/testing/scripts.js"></script>
+    <script nomodule src="../../../../../dist/ionic/ionic.js"></script>
+    <script type="module" src="../../../../../dist/ionic/ionic.esm.js"></script>
+    <style>
+      .grid {
+        display: grid;
+        grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
+        grid-row-gap: 30px;
+        grid-column-gap: 30px;
+      }
+
+      h2 {
+        font-size: 12px;
+        font-weight: normal;
+
+        color: var(--ion-color-step-600);
+
+        margin-top: 10px;
+        margin-bottom: 5px;
+      }
+
+      .validation-info {
+        margin: 20px;
+        padding: 10px;
+        background: var(--ion-color-light);
+        border-radius: 4px;
+      }
+    </style>
+  </head>
+
+  <body>
+    <ion-app>
+      <ion-header>
+        <ion-toolbar>
+          <ion-title>Select - Validation Test</ion-title>
+        </ion-toolbar>
+      </ion-header>
+
+      <ion-content class="ion-padding">
+        <div class="validation-info">
+          <h2>Screen Reader Testing Instructions:</h2>
+          <ol>
+            <li>Enable your screen reader (VoiceOver, NVDA, JAWS, etc.)</li>
+            <li>Tab through the form fields</li>
+            <li>When you tab away from an empty required field, the error should be announced immediately</li>
+            <li>The error text should be announced BEFORE the next field is announced</li>
+            <li>Test in Chrome, Safari, and Firefox to verify consistent behavior</li>
+          </ol>
+        </div>
+
+        <div class="grid">
+          <div>
+            <h2>Required Field</h2>
+            <ion-select
+              id="fruits-select"
+              label="Fruits"
+              placeholder="Select one"
+              interface="alert"
+              helper-text="You must select an option to continue"
+              error-text="This field is required"
+              required
+            >
+              <ion-select-option value="apples">Apples</ion-select-option>
+              <ion-select-option value="oranges">Oranges</ion-select-option>
+              <ion-select-option value="pears">Pears</ion-select-option>
+            </ion-select>
+          </div>
+
+          <div>
+            <h2>Optional Field (No Validation)</h2>
+            <ion-select
+              id="optional-select"
+              label="Colors"
+              placeholder="Select one"
+              interface="alert"
+              helper-text="You can skip this field"
+            >
+              <ion-select-option value="red">Red</ion-select-option>
+              <ion-select-option value="blue">Blue</ion-select-option>
+              <ion-select-option value="green">Green</ion-select-option>
+            </ion-select>
+          </div>
+        </div>
+
+        <div class="ion-padding">
+          <ion-button id="submit-btn" expand="block" disabled>Submit Form</ion-button>
+          <ion-button id="reset-btn" expand="block" fill="outline">Reset Form</ion-button>
+        </div>
+      </ion-content>
+    </ion-app>
+
+    <script>
+      // Simple validation logic
+      const selects = document.querySelectorAll('ion-select');
+      const submitBtn = document.getElementById('submit-btn');
+      const resetBtn = document.getElementById('reset-btn');
+
+      // Track which fields have been touched
+      const touchedFields = new Set();
+
+      // Validation functions
+      const validators = {
+        'fruits-select': (value) => {
+          return value !== '' && value !== undefined;
+        },
+        'optional-select': () => true, // Always valid
+      };
+
+      function validateField(select) {
+        const selectId = select.id;
+        const value = select.value;
+        const isValid = validators[selectId] ? validators[selectId](value) : true;
+
+        // Only show validation state if field has been touched
+        if (touchedFields.has(selectId)) {
+          if (isValid) {
+            select.classList.remove('ion-invalid');
+            select.classList.add('ion-valid');
+          } else {
+            select.classList.remove('ion-valid');
+            select.classList.add('ion-invalid');
+          }
+          select.classList.add('ion-touched');
+        }
+
+        return isValid;
+      }
+
+      function validateForm() {
+        let allValid = true;
+        selects.forEach((select) => {
+          if (select.id !== 'optional-select') {
+            const isValid = validateField(select);
+            if (!isValid) {
+              allValid = false;
+            }
+          }
+        });
+        submitBtn.disabled = !allValid;
+        return allValid;
+      }
+
+      // Add event listeners
+      selects.forEach((select) => {
+        // Mark as touched on blur
+        select.addEventListener('ionBlur', (e) => {
+          console.log('Blur event on:', select.id);
+          touchedFields.add(select.id);
+          validateField(select);
+          validateForm();
+
+          const isInvalid = select.classList.contains('ion-invalid');
+          if (isInvalid) {
+            console.log('Field marked invalid:', select.label, select.errorText);
+          }
+        });
+
+        // Validate on change
+        select.addEventListener('ionChange', (e) => {
+          console.log('Change event on:', select.id);
+          if (touchedFields.has(select.id)) {
+            validateField(select);
+            validateForm();
+          }
+        });
+      });
+
+      // Reset button
+      resetBtn.addEventListener('click', () => {
+        selects.forEach((select) => {
+          select.value = '';
+          select.classList.remove('ion-valid', 'ion-invalid', 'ion-touched');
+        });
+        touchedFields.clear();
+        submitBtn.disabled = true;
+      });
+
+      // Submit button
+      submitBtn.addEventListener('click', () => {
+        if (validateForm()) {
+          alert('Form submitted successfully!');
+        }
+      });
+
+      // Initial setup
+      validateForm();
+    </script>
+  </body>
+</html>