fix(datetime): if no default value, don't highlight active day until one is selected (#25151)

core/src/components/datetime/datetime.tsx

@@ -68,6 +68,16 @@ export class Datetime implements ComponentInterface {
   private clearFocusVisible?: () => void;
   private overlayIsPresenting = false;
 
+  /**
+   * Whether to highlight the active day with a solid circle (as opposed
+   * to the outline circle around today). If you don't specify an initial
+   * value for the datetime, it doesn't automatically init to a default to
+   * avoid unwanted change events firing. If the solid circle were still
+   * shown then, it would look like a date had already been selected, which
+   * is misleading UX.
+   */
+  private highlightActiveParts = false;
+
   private parsedMinuteValues?: number[];
   private parsedHourValues?: number[];
   private parsedMonthValues?: number[];
@@ -1058,6 +1068,7 @@ export class Datetime implements ComponentInterface {
   };
 
   private processValue = (value?: string | null) => {
+    this.highlightActiveParts = !!value;
     const valueToProcess = value || getToday();
     const { month, day, year, hour, minute, tzOffset } = parseDate(valueToProcess);
 
@@ -1349,6 +1360,7 @@ export class Datetime implements ComponentInterface {
   }
 
   private renderMonth(month: number, year: number) {
+    const { highlightActiveParts } = this;
     const yearAllowed = this.parsedYearValues === undefined || this.parsedYearValues.includes(year);
     const monthAllowed = this.parsedMonthValues === undefined || this.parsedMonthValues.includes(month);
     const isCalMonthDisabled = !yearAllowed || !monthAllowed;
@@ -1424,7 +1436,7 @@ export class Datetime implements ComponentInterface {
                 class={{
                   'calendar-day-padding': day === null,
                   'calendar-day': true,
-                  'calendar-day-active': isActive,
+                  'calendar-day-active': isActive && highlightActiveParts,
                   'calendar-day-today': isToday,
                 }}
                 aria-selected={ariaSelected}
@@ -1434,6 +1446,14 @@ export class Datetime implements ComponentInterface {
                     return;
                   }
 
+                  /**
+                   * Note that for datetimes with confirm/cancel buttons, the value
+                   * isn't updated until you call confirm(). We need to bring the
+                   * solid circle back on day click for UX reasons, rather than only
+                   * show the circle if `value` is truthy.
+                   */
+                  this.highlightActiveParts = true;
+
                   this.setWorkingParts({
                     ...this.workingParts,
                     month,

core/src/components/datetime/test/basic/datetime.e2e.ts

@@ -0,0 +1,30 @@
+import { expect } from '@playwright/test';
+import type { E2EPage } from '@utils/test/playwright';
+import { test } from '@utils/test/playwright';
+
+test.describe('datetime: selecting a day', () => {
+  const testHighlight = async (page: E2EPage, datetimeID: string) => {
+    const today = new Date();
+    await page.goto('/src/components/datetime/test/basic');
+
+    const todayBtn = page.locator(
+      `#${datetimeID} .calendar-day[data-day='${today.getDate()}'][data-month='${today.getMonth() + 1}']`
+    );
+
+    expect(todayBtn).toHaveClass(/calendar-day-today/);
+    expect(todayBtn).not.toHaveClass(/calendar-day-active/);
+
+    await todayBtn.click();
+    await page.waitForChanges();
+
+    expect(todayBtn).toHaveClass(/calendar-day-active/);
+  };
+
+  test('should not highlight a day until one is selected', async ({ page }) => {
+    await testHighlight(page, 'inline-datetime-no-value');
+  });
+
+  test('should not highlight a day until one is selected, with default-buttons', async ({ page }) => {
+    await testHighlight(page, 'custom-datetime');
+  });
+});

core/src/components/datetime/test/basic/index.html

@@ -261,6 +261,11 @@
             <ion-datetime value="2020-03-14T14:23:00.000Z" id="inline-datetime"></ion-datetime>
           </div>
 
+          <div class="grid-item">
+            <h2>Inline - No Default Value</h2>
+            <ion-datetime id="inline-datetime-no-value"></ion-datetime>
+          </div>
+
           <div class="grid-item">
             <h2>Popover</h2>
             <ion-button onclick="presentPopover(defaultPopover, event)">Present Popover</ion-button>