fix(datepicker): better support for input and change events (#4826)

src/demo-app/datepicker/datepicker-demo.html

@@ -37,7 +37,9 @@ <h2>Result</h2>
            [min]="minDate"
            [max]="maxDate"
            [mdDatepickerFilter]="filterOdd ? dateFilter : null"
-           placeholder="Pick a date">
+           placeholder="Pick a date"
+           (dateInput)="onDateInput($event)"
+           (dateChange)="onDateChange($event)">
     <md-error *ngIf="resultPickerModel.hasError('mdDatepickerMin')">Too early!</md-error>
     <md-error *ngIf="resultPickerModel.hasError('mdDatepickerMax')">Too late!</md-error>
     <md-error *ngIf="resultPickerModel.hasError('mdDatepickerFilter')">Date unavailable!</md-error>
@@ -50,6 +52,9 @@ <h2>Result</h2>
       [startView]="yearView ? 'year' : 'month'">
   </md-datepicker>
 </p>
+<p>Last input: {{lastDateInput}}</p>
+<p>Last change: {{lastDateChange}}</p>
+<br>
 <p>
   <input #resultPickerModel2
          [mdDatepicker]="resultPicker2"

src/demo-app/datepicker/datepicker-demo.ts

@@ -1,4 +1,5 @@
 import {Component} from '@angular/core';
+import {MdDatepickerInputEvent} from '@angular/material';
 
 
 @Component({
@@ -17,5 +18,11 @@ export class DatepickerDemo {
   maxDate: Date;
   startAt: Date;
   date: Date;
+  lastDateInput: Date | null;
+  lastDateChange: Date | null;
+
   dateFilter = (date: Date) => date.getMonth() % 2 == 1 && date.getDate() % 2 == 0;
+
+  onDateInput = (e: MdDatepickerInputEvent<Date>) => this.lastDateInput = e.value;
+  onDateChange = (e: MdDatepickerInputEvent<Date>) => this.lastDateChange = e.value;
 }

src/lib/datepicker/datepicker-input.ts

@@ -16,6 +16,7 @@ import {
   Input,
   OnDestroy,
   Optional,
+  Output,
   Renderer2
 } from '@angular/core';
 import {MdDatepicker} from './datepicker';
@@ -52,6 +53,21 @@ export const MD_DATEPICKER_VALIDATORS: any = {
 };
 
 
+/**
+ * An event used for datepicker input and change events. We don't always have access to a native
+ * input or change event because the event may have been triggered by the user clicking on the
+ * calendar popup. For consistency, we always use MdDatepickerInputEvent instead.
+ */
+export class MdDatepickerInputEvent<D> {
+  /** The new value for the target datepicker input. */
+  value: D | null;
+
+  constructor(public target: MdDatepickerInput<D>, public targetElement: HTMLElement) {
+    this.value = this.target.value;
+  }
+}
+
+
 /** Directive used to connect an input to a MdDatepicker. */
 @Directive({
   selector: 'input[mdDatepicker], input[matDatepicker]',
@@ -63,9 +79,11 @@ export const MD_DATEPICKER_VALIDATORS: any = {
     '[attr.max]': 'max ? _dateAdapter.getISODateString(max) : null',
     '[disabled]': 'disabled',
     '(input)': '_onInput($event.target.value)',
+    '(change)': '_onChange()',
     '(blur)': '_onTouched()',
     '(keydown)': '_onKeydown($event)',
-  }
+  },
+  exportAs: 'mdDatepickerInput',
 })
 export class MdDatepickerInput<D> implements AfterContentInit, ControlValueAccessor, OnDestroy,
     Validator {
@@ -133,6 +151,12 @@ export class MdDatepickerInput<D> implements AfterContentInit, ControlValueAcces
   }
   private _disabled: boolean;
 
+  /** Emits when a `change` event is fired on this `<input>`. */
+  @Output() dateChange = new EventEmitter<MdDatepickerInputEvent<D>>();
+
+  /** Emits when an `input` event is fired on this `<input>`. */
+  @Output() dateInput = new EventEmitter<MdDatepickerInputEvent<D>>();
+
   /** Emits when the value changes (either due to user input or programmatic change). */
   _valueChange = new EventEmitter<D|null>();
 
@@ -188,6 +212,8 @@ export class MdDatepickerInput<D> implements AfterContentInit, ControlValueAcces
           this._datepicker.selectedChanged.subscribe((selected: D) => {
             this.value = selected;
             this._cvaOnChange(selected);
+            this.dateInput.emit(new MdDatepickerInputEvent(this, this._elementRef.nativeElement));
+            this.dateChange.emit(new MdDatepickerInputEvent(this, this._elementRef.nativeElement));
           });
     }
   }
@@ -245,5 +271,10 @@ export class MdDatepickerInput<D> implements AfterContentInit, ControlValueAcces
     let date = this._dateAdapter.parse(value, this._dateFormats.parse.dateInput);
     this._cvaOnChange(date);
     this._valueChange.emit(date);
+    this.dateInput.emit(new MdDatepickerInputEvent(this, this._elementRef.nativeElement));
+  }
+
+  _onChange() {
+    this.dateChange.emit(new MdDatepickerInputEvent(this, this._elementRef.nativeElement));
   }
 }

src/lib/datepicker/datepicker.md

@@ -82,6 +82,17 @@ Each validation property has a different error that can be checked:
  * A value that violates the `min` property will have a `mdDatepickerMin` error.
  * A value that violates the `max` property will have a `mdDatepickerMax` error.
  * A value that violates the `mdDatepickerFilter` property will have a `mdDatepickerFilter` error.
+
+### Input and change events
+The input's native `input` and `change` events will only trigger due to user interaction with the
+input element; they will not fire when the user selects a date from the calendar popup. Because of
+this limitation, the datepicker input also has support for `dateInput` and `dateChange` events.
+These trigger when the user interacts with either the input or the popup.
+
+```html
+<input [mdDatepicker]="d" (dateInput)="onInput($event)" (dateChange)="onChange($event)">
+<md-datepicker #d></md-datepicker>
+```
 
 ### Touch UI mode
 The datepicker normally opens as a popup under the input. However this is not ideal for touch

src/lib/datepicker/datepicker.spec.ts

@@ -29,6 +29,7 @@ describe('MdDatepicker', () => {
           ReactiveFormsModule,
         ],
         declarations: [
+          DatepickerWithChangeAndInputEvents,
           DatepickerWithFilterAndValidation,
           DatepickerWithFormControl,
           DatepickerWithMinAndMaxValidation,
@@ -689,6 +690,81 @@ describe('MdDatepicker', () => {
         expect(cells[1].classList).not.toContain('mat-calendar-body-disabled');
       });
     });
+
+    describe('datepicker with change and input events', () => {
+      let fixture: ComponentFixture<DatepickerWithChangeAndInputEvents>;
+      let testComponent: DatepickerWithChangeAndInputEvents;
+      let inputEl: HTMLInputElement;
+
+      beforeEach(async(() => {
+        fixture = TestBed.createComponent(DatepickerWithChangeAndInputEvents);
+        fixture.detectChanges();
+
+        testComponent = fixture.componentInstance;
+        inputEl = fixture.debugElement.query(By.css('input')).nativeElement;
+
+        spyOn(testComponent, 'onChange');
+        spyOn(testComponent, 'onInput');
+        spyOn(testComponent, 'onDateChange');
+        spyOn(testComponent, 'onDateInput');
+      }));
+
+      afterEach(async(() => {
+        testComponent.datepicker.close();
+        fixture.detectChanges();
+      }));
+
+      it('should fire input and dateInput events when user types input', () => {
+        expect(testComponent.onChange).not.toHaveBeenCalled();
+        expect(testComponent.onDateChange).not.toHaveBeenCalled();
+        expect(testComponent.onInput).not.toHaveBeenCalled();
+        expect(testComponent.onDateInput).not.toHaveBeenCalled();
+
+        dispatchFakeEvent(inputEl, 'input');
+        fixture.detectChanges();
+
+        expect(testComponent.onChange).not.toHaveBeenCalled();
+        expect(testComponent.onDateChange).not.toHaveBeenCalled();
+        expect(testComponent.onInput).toHaveBeenCalled();
+        expect(testComponent.onDateInput).toHaveBeenCalled();
+      });
+
+      it('should fire change and dateChange events when user commits typed input', () => {
+        expect(testComponent.onChange).not.toHaveBeenCalled();
+        expect(testComponent.onDateChange).not.toHaveBeenCalled();
+        expect(testComponent.onInput).not.toHaveBeenCalled();
+        expect(testComponent.onDateInput).not.toHaveBeenCalled();
+
+        dispatchFakeEvent(inputEl, 'change');
+        fixture.detectChanges();
+
+        expect(testComponent.onChange).toHaveBeenCalled();
+        expect(testComponent.onDateChange).toHaveBeenCalled();
+        expect(testComponent.onInput).not.toHaveBeenCalled();
+        expect(testComponent.onDateInput).not.toHaveBeenCalled();
+      });
+
+      it('should fire dateChange and dateInput events when user selects calendar date', () => {
+        expect(testComponent.onChange).not.toHaveBeenCalled();
+        expect(testComponent.onDateChange).not.toHaveBeenCalled();
+        expect(testComponent.onInput).not.toHaveBeenCalled();
+        expect(testComponent.onDateInput).not.toHaveBeenCalled();
+
+        testComponent.datepicker.open();
+        fixture.detectChanges();
+
+        expect(document.querySelector('md-dialog-container')).not.toBeNull();
+
+        let cells = document.querySelectorAll('.mat-calendar-body-cell');
+        dispatchMouseEvent(cells[0], 'click');
+        fixture.detectChanges();
+
+        expect(testComponent.onChange).not.toHaveBeenCalled();
+        expect(testComponent.onDateChange).toHaveBeenCalled();
+        expect(testComponent.onInput).not.toHaveBeenCalled();
+        expect(testComponent.onDateInput).toHaveBeenCalled();
+      });
+    });
   });
 
   describe('with missing DateAdapter and MD_DATE_FORMATS', () => {
@@ -924,3 +1000,23 @@ class DatepickerWithFilterAndValidation {
   date: Date;
   filter = (date: Date) => date.getDate() != 1;
 }
+
+
+@Component({
+  template: `
+    <input [mdDatepicker]="d" (change)="onChange()" (input)="onInput()"
+           (dateChange)="onDateChange()" (dateInput)="onDateInput()">
+    <md-datepicker #d [touchUi]="true"></md-datepicker>
+  `
+})
+class DatepickerWithChangeAndInputEvents {
+  @ViewChild('d') datepicker: MdDatepicker<Date>;
+
+  onChange() {}
+
+  onInput() {}
+
+  onDateChange() {}
+
+  onDateInput() {}
+}