feat(select): support basic usage without @angular/forms (#5871)

* feat(select): support basic usage without @angular/forms

Currently `md-select` can only really be used together with `@angular/forms` which is overkill for simple usages where it only sets a value (for example, the only reason the paginator module brings in the `FormsModule` is the select). These changes introduce the `value` two-way binding that can be used to read/write the value without using `ngModel` or a `formControl`. This also aligns it with the input module.

Relates to #5717.

* chore: add demo

src/demo-app/select/select-demo.html

@@ -65,6 +65,22 @@ Space above cards: <input type="number" [formControl]="topHeightCtrl">
     </md-card-content>
   </md-card>
 
+  <md-card>
+    <md-card-subtitle>Without Angular forms</md-card-subtitle>
+
+    <md-select placeholder="Digimon" [(value)]="currentDigimon">
+      <md-option>None</md-option>
+      <md-option *ngFor="let creature of digimon" [value]="creature.value">
+        {{ creature.viewValue }}
+      </md-option>
+    </md-select>
+
+    <p>Value: {{ currentDigimon }}</p>
+
+    <button md-button (click)="currentDigimon='pajiramon-3'">SET VALUE</button>
+    <button md-button (click)="currentDigimon=null">RESET</button>
+  </md-card>
+
   <md-card>
     <md-card-subtitle>Option groups</md-card-subtitle>
 

src/demo-app/select/select-demo.ts

@@ -17,6 +17,7 @@ export class SelectDemo {
   currentDrink: string;
   currentPokemon: string[];
   currentPokemonFromGroup: string;
+  currentDigimon: string;
   latestChangeEvent: MdSelectChange;
   floatPlaceholder: string = 'auto';
   foodControl = new FormControl('pizza-1');
@@ -94,6 +95,15 @@ export class SelectDemo {
     }
   ];
 
+  digimon = [
+    { value: 'mihiramon-0', viewValue: 'Mihiramon' },
+    { value: 'sandiramon-1', viewValue: 'Sandiramon' },
+    { value: 'sinduramon-2', viewValue: 'Sinduramon' },
+    { value: 'pajiramon-3', viewValue: 'Pajiramon' },
+    { value: 'vajiramon-4', viewValue: 'Vajiramon' },
+    { value: 'indramon-5', viewValue: 'Indramon' }
+  ];
+
   toggleDisabled() {
     this.foodControl.enabled ? this.foodControl.disable() : this.foodControl.enable();
   }

src/lib/select/select.spec.ts

@@ -63,7 +63,10 @@ describe('MdSelect', () => {
         ResetValuesSelect,
         FalsyValueSelect,
         SelectWithGroups,
-        InvalidSelectInForm
+        InvalidSelectInForm,
+        BasicSelectWithoutForms,
+        BasicSelectWithoutFormsPreselected,
+        BasicSelectWithoutFormsMultiple
       ],
       providers: [
         {provide: OverlayContainer, useFactory: () => {
@@ -706,6 +709,138 @@ describe('MdSelect', () => {
 
   });
 
+  describe('selection without Angular forms', () => {
+    it('should set the value when options are clicked', () => {
+      const fixture = TestBed.createComponent(BasicSelectWithoutForms);
+
+      fixture.detectChanges();
+      expect(fixture.componentInstance.selectedFood).toBeFalsy();
+
+      const trigger = fixture.debugElement.query(By.css('.mat-select-trigger')).nativeElement;
+
+      trigger.click();
+      fixture.detectChanges();
+
+      (overlayContainerElement.querySelector('md-option') as HTMLElement).click();
+      fixture.detectChanges();
+
+      expect(fixture.componentInstance.selectedFood).toBe('steak-0');
+      expect(fixture.componentInstance.select.value).toBe('steak-0');
+      expect(trigger.textContent).toContain('Steak');
+
+      trigger.click();
+      fixture.detectChanges();
+
+      (overlayContainerElement.querySelectorAll('md-option')[2] as HTMLElement).click();
+      fixture.detectChanges();
+
+      expect(fixture.componentInstance.selectedFood).toBe('sandwich-2');
+      expect(fixture.componentInstance.select.value).toBe('sandwich-2');
+      expect(trigger.textContent).toContain('Sandwich');
+    });
+
+    it('should mark options as selected when the value is set', () => {
+      const fixture = TestBed.createComponent(BasicSelectWithoutForms);
+
+      fixture.detectChanges();
+      fixture.componentInstance.selectedFood = 'sandwich-2';
+      fixture.detectChanges();
+
+      const trigger = fixture.debugElement.query(By.css('.mat-select-trigger')).nativeElement;
+      expect(trigger.textContent).toContain('Sandwich');
+
+      trigger.click();
+      fixture.detectChanges();
+
+      const option = overlayContainerElement.querySelectorAll('md-option')[2];
+
+      expect(option.classList).toContain('mat-selected');
+      expect(fixture.componentInstance.select.value).toBe('sandwich-2');
+    });
+
+    it('should reset the placeholder when a null value is set', () => {
+      const fixture = TestBed.createComponent(BasicSelectWithoutForms);
+
+      fixture.detectChanges();
+      expect(fixture.componentInstance.selectedFood).toBeFalsy();
+
+      const trigger = fixture.debugElement.query(By.css('.mat-select-trigger')).nativeElement;
+
+      trigger.click();
+      fixture.detectChanges();
+
+      (overlayContainerElement.querySelector('md-option') as HTMLElement).click();
+      fixture.detectChanges();
+
+      expect(fixture.componentInstance.selectedFood).toBe('steak-0');
+      expect(fixture.componentInstance.select.value).toBe('steak-0');
+      expect(trigger.textContent).toContain('Steak');
+
+      fixture.componentInstance.selectedFood = null;
+      fixture.detectChanges();
+
+      expect(fixture.componentInstance.select.value).toBeNull();
+      expect(trigger.textContent).not.toContain('Steak');
+    });
+
+    it('should reflect the preselected value', async(() => {
+      const fixture = TestBed.createComponent(BasicSelectWithoutFormsPreselected);
+
+      fixture.detectChanges();
+      fixture.whenStable().then(() => {
+        const trigger = fixture.debugElement.query(By.css('.mat-select-trigger')).nativeElement;
+
+        fixture.detectChanges();
+        expect(trigger.textContent).toContain('Pizza');
+
+        trigger.click();
+        fixture.detectChanges();
+
+        const option = overlayContainerElement.querySelectorAll('md-option')[1];
+
+        expect(option.classList).toContain('mat-selected');
+        expect(fixture.componentInstance.select.value).toBe('pizza-1');
+      });
+    }));
+
+    it('should be able to select multiple values', () => {
+      const fixture = TestBed.createComponent(BasicSelectWithoutFormsMultiple);
+
+      fixture.detectChanges();
+      expect(fixture.componentInstance.selectedFoods).toBeFalsy();
+
+      const trigger = fixture.debugElement.query(By.css('.mat-select-trigger')).nativeElement;
+
+      trigger.click();
+      fixture.detectChanges();
+
+      const options =
+          overlayContainerElement.querySelectorAll('md-option') as NodeListOf<HTMLElement>;
+
+      options[0].click();
+      fixture.detectChanges();
+
+      expect(fixture.componentInstance.selectedFoods).toEqual(['steak-0']);
+      expect(fixture.componentInstance.select.value).toEqual(['steak-0']);
+      expect(trigger.textContent).toContain('Steak');
+
+      options[2].click();
+      fixture.detectChanges();
+
+      expect(fixture.componentInstance.selectedFoods).toEqual(['steak-0', 'sandwich-2']);
+      expect(fixture.componentInstance.select.value).toEqual(['steak-0', 'sandwich-2']);
+      expect(trigger.textContent).toContain('Steak, Sandwich');
+
+      options[1].click();
+      fixture.detectChanges();
+
+      expect(fixture.componentInstance.selectedFoods).toEqual(['steak-0', 'pizza-1', 'sandwich-2']);
+      expect(fixture.componentInstance.select.value).toEqual(['steak-0', 'pizza-1', 'sandwich-2']);
+      expect(trigger.textContent).toContain('Steak, Pizza, Sandwich');
+    });
+
+  });
+
   describe('disabled behavior', () => {
 
     it('should disable itself when control is disabled programmatically', () => {
@@ -2361,7 +2496,6 @@ describe('MdSelect', () => {
 
   });
 
-
   describe('reset values', () => {
     let fixture: ComponentFixture<ResetValuesSelect>;
     let trigger: HTMLElement;
@@ -2892,3 +3026,63 @@ class SelectWithGroups {
 class InvalidSelectInForm {
   value: any;
 }
+
+
+@Component({
+  template: `
+    <md-select placeholder="Food" [(value)]="selectedFood">
+      <md-option *ngFor="let food of foods" [value]="food.value">
+        {{ food.viewValue }}
+      </md-option>
+    </md-select>
+  `
+})
+class BasicSelectWithoutForms {
+  selectedFood: string | null;
+  foods: any[] = [
+    { value: 'steak-0', viewValue: 'Steak' },
+    { value: 'pizza-1', viewValue: 'Pizza' },
+    { value: 'sandwich-2', viewValue: 'Sandwich' },
+  ];
+
+  @ViewChild(MdSelect) select: MdSelect;
+}
+
+@Component({
+  template: `
+    <md-select placeholder="Food" [(value)]="selectedFood">
+      <md-option *ngFor="let food of foods" [value]="food.value">
+        {{ food.viewValue }}
+      </md-option>
+    </md-select>
+  `
+})
+class BasicSelectWithoutFormsPreselected {
+  selectedFood = 'pizza-1';
+  foods: any[] = [
+    { value: 'steak-0', viewValue: 'Steak' },
+    { value: 'pizza-1', viewValue: 'Pizza' },
+  ];
+
+  @ViewChild(MdSelect) select: MdSelect;
+}
+
+@Component({
+  template: `
+    <md-select placeholder="Food" [(value)]="selectedFoods" multiple>
+      <md-option *ngFor="let food of foods" [value]="food.value">
+        {{ food.viewValue }}
+      </md-option>
+    </md-select>
+  `
+})
+class BasicSelectWithoutFormsMultiple {
+  selectedFoods: string[];
+  foods: any[] = [
+    { value: 'steak-0', viewValue: 'Steak' },
+    { value: 'pizza-1', viewValue: 'Pizza' },
+    { value: 'sandwich-2', viewValue: 'Sandwich' },
+  ];
+
+  @ViewChild(MdSelect) select: MdSelect;
+}

src/lib/select/select.ts

@@ -325,6 +325,15 @@ export class MdSelect extends _MdSelectMixinBase implements AfterContentInit, On
     }
   }
 
+  /** Value of the select control. */
+  @Input()
+  get value() { return this._value; }
+  set value(newValue: any) {
+    this.writeValue(newValue);
+    this._value = newValue;
+  }
+  private _value: any;
+
   /** Aria label of the select. If not specified, the placeholder will be used as label. */
   @Input('aria-label') ariaLabel: string = '';
 
@@ -345,6 +354,13 @@ export class MdSelect extends _MdSelectMixinBase implements AfterContentInit, On
   /** Event emitted when the selected value has been changed by the user. */
   @Output() change: EventEmitter<MdSelectChange> = new EventEmitter<MdSelectChange>();
 
+  /**
+   * Event that emits whenever the raw value of the select changes. This is here primarily
+   * to facilitate the two-way binding for the `value` input.
+   * @docs-private
+   */
+  @Output() valueChange = new EventEmitter<any>();
+
   constructor(
     private _viewportRuler: ViewportRuler,
     private _changeDetectorRef: ChangeDetectorRef,
@@ -377,11 +393,11 @@ export class MdSelect extends _MdSelectMixinBase implements AfterContentInit, On
     this._changeSubscription = startWith.call(this.options.changes, null).subscribe(() => {
       this._resetOptions();
 
-      if (this._control) {
-        // Defer setting the value in order to avoid the "Expression
-        // has changed after it was checked" errors from Angular.
-        Promise.resolve(null).then(() => this._setSelectionByValue(this._control.value));
-      }
+      // Defer setting the value in order to avoid the "Expression
+      // has changed after it was checked" errors from Angular.
+      Promise.resolve().then(() => {
+        this._setSelectionByValue(this._control ? this._control.value : this._value);
+      });
     });
   }
 
@@ -750,8 +766,10 @@ export class MdSelect extends _MdSelectMixinBase implements AfterContentInit, On
       valueToEmit = this.selected ? this.selected.value : fallbackValue;
     }
 
+    this._value = valueToEmit;
     this._onChange(valueToEmit);
     this.change.emit(new MdSelectChange(this, valueToEmit));
+    this.valueChange.emit(valueToEmit);
   }
 
   /** Records option IDs to pass to the aria-owns property. */