feat(datetime): default to now or max. Fixes #9846

Author: mlynch

src/components/datetime/datetime.ts

@@ -510,6 +510,7 @@ export class DateTime extends BaseInput<DateTimeData> implements AfterContentIni
     if (this.isFocus() || this._disabled) {
       return;
     }
+
     console.debug('datetime, open picker');
 
     // the user may have assigned some options specifically for the alert
@@ -548,6 +549,11 @@ export class DateTime extends BaseInput<DateTimeData> implements AfterContentIni
    * @hidden
    */
   generate() {
+    // If the date doesn't have a value yet, set it to now or the max value
+    if (Object.keys(this._value).length === 0) {
+      this._value = this.getDefaultValue();
+    }
+
     const picker = this._picker;
     // if a picker format wasn't provided, then fallback
     // to use the display format
@@ -838,6 +844,17 @@ export class DateTime extends BaseInput<DateTimeData> implements AfterContentIni
     }
   }
 
+  /**
+   * Get the default value to show when none is provided,
+   * and within the bounds of the max value
+   * @private
+   */
+  getDefaultValue() {
+    if (this.max) {
+      return parseDate(this.max);
+    }
+    return parseDate((new Date).toISOString());
+  }
 }
 
 /**

src/components/datetime/test/datetime.spec.ts

@@ -4,7 +4,7 @@ import { DateTime } from '../datetime';
 import { Form } from '../../../util/form';
 import { Picker } from '../../picker/picker';
 import { PickerController } from '../../picker/picker-controller';
-import * as datetime from '../../../util/datetime-util';
+import * as datetimeUtil from '../../../util/datetime-util';
 import { mockApp, mockConfig, mockElementRef, mockRenderer } from '../../../util/mock-providers';
 
 
@@ -14,6 +14,26 @@ describe('DateTime', () => {
 
   describe('validate', () => {
 
+    fit('should default to now if no initial value or bounds supplied', () => {
+      const now = datetimeUtil.parseDate(new Date().toISOString());
+      datetime.generate();
+      const val = datetime.getValue();
+      expect(val.year).toEqual(now.year);
+      expect(val.month).toEqual(now.month);
+      expect(val.day).toEqual(now.day);
+      expect(val.hour).toEqual(now.hour);
+      expect(val.minute).toEqual(now.minute);
+    });
+
+    fit('should default to max if no initial value supplied but max specified', () => {
+      datetime.max = '1987-10-19';
+      datetime.generate();
+      const val = datetime.getValue();
+      expect(val.year).toEqual(1987);
+      expect(val.month).toEqual(10);
+      expect(val.day).toEqual(19);
+    });
+
     it('should restrict January 1-14, 2000 from selection, then allow it, and restrict December 15-31, 2001', () => {
       datetime.max = '2001-12-15';
       datetime.min = '2000-01-15';
@@ -683,7 +703,7 @@ describe('DateTime', () => {
   console.warn = function(){};
 
   // pt-br
-  var customLocale: datetime.LocaleData = {
+  var customLocale: datetimeUtil.LocaleData = {
     dayNames: [
       'domingo',
       'segunda-feira',