feat(forms): add range value support

modules/@angular/forms/src/directives.ts

@@ -16,6 +16,7 @@ import {NgModel} from './directives/ng_model';
 import {NgModelGroup} from './directives/ng_model_group';
 import {NumberValueAccessor} from './directives/number_value_accessor';
 import {RadioControlValueAccessor} from './directives/radio_control_value_accessor';
+import {RangeValueAccessor} from './directives/range_value_accessor';
 import {FormControlDirective} from './directives/reactive_directives/form_control_directive';
 import {FormControlName} from './directives/reactive_directives/form_control_name';
 import {FormGroupDirective} from './directives/reactive_directives/form_group_directive';
@@ -34,6 +35,7 @@ export {NgModel} from './directives/ng_model';
 export {NgModelGroup} from './directives/ng_model_group';
 export {NumberValueAccessor} from './directives/number_value_accessor';
 export {RadioControlValueAccessor} from './directives/radio_control_value_accessor';
+export {RangeValueAccessor} from './directives/range_value_accessor';
 export {FormControlDirective} from './directives/reactive_directives/form_control_directive';
 export {FormControlName} from './directives/reactive_directives/form_control_name';
 export {FormGroupDirective} from './directives/reactive_directives/form_group_directive';
@@ -44,9 +46,9 @@ export {MaxLengthValidator, MinLengthValidator, PatternValidator, RequiredValida
 
 export const SHARED_FORM_DIRECTIVES: Type<any>[] = [
   NgSelectOption, NgSelectMultipleOption, DefaultValueAccessor, NumberValueAccessor,
-  CheckboxControlValueAccessor, SelectControlValueAccessor, SelectMultipleControlValueAccessor,
-  RadioControlValueAccessor, NgControlStatus, NgControlStatusGroup, RequiredValidator,
-  MinLengthValidator, MaxLengthValidator, PatternValidator
+  RangeValueAccessor, CheckboxControlValueAccessor, SelectControlValueAccessor,
+  SelectMultipleControlValueAccessor, RadioControlValueAccessor, NgControlStatus,
+  NgControlStatusGroup, RequiredValidator, MinLengthValidator, MaxLengthValidator, PatternValidator
 ];
 
 export const TEMPLATE_DRIVEN_DIRECTIVES: Type<any>[] = [NgModel, NgModelGroup, NgForm];

modules/@angular/forms/src/directives/range_value_accessor.ts

@@ -0,0 +1,57 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import {Directive, ElementRef, Provider, Renderer, forwardRef} from '@angular/core';
+
+import {ControlValueAccessor, NG_VALUE_ACCESSOR} from './control_value_accessor';
+
+export const RANGE_VALUE_ACCESSOR: Provider = {
+  provide: NG_VALUE_ACCESSOR,
+  useExisting: forwardRef(() => RangeValueAccessor),
+  multi: true
+};
+
+/**
+ * The accessor for writing a range value and listening to changes that is used by the
+ * {@link NgModel}, {@link FormControlDirective}, and {@link FormControlName} directives.
+ *
+ *  ### Example
+ *  ```
+ *  <input type="range" [(ngModel)]="age" >
+ *  ```
+ */
+@Directive({
+  selector:
+      'input[type=range][formControlName],input[type=range][formControl],input[type=range][ngModel]',
+  host: {
+    '(change)': 'onChange($event.target.value)',
+    '(input)': 'onChange($event.target.value)',
+    '(blur)': 'onTouched()'
+  },
+  providers: [RANGE_VALUE_ACCESSOR]
+})
+export class RangeValueAccessor implements ControlValueAccessor {
+  onChange = (_: any) => {};
+  onTouched = () => {};
+
+  constructor(private _renderer: Renderer, private _elementRef: ElementRef) {}
+
+  writeValue(value: any): void {
+    this._renderer.setElementProperty(this._elementRef.nativeElement, 'value', parseFloat(value));
+  }
+
+  registerOnChange(fn: (_: number) => void): void {
+    this.onChange = (value) => { fn(value == '' ? null : parseFloat(value)); };
+  }
+
+  registerOnTouched(fn: () => void): void { this.onTouched = fn; }
+
+  setDisabledState(isDisabled: boolean): void {
+    this._renderer.setElementProperty(this._elementRef.nativeElement, 'disabled', isDisabled);
+  }
+}

modules/@angular/forms/src/directives/shared.ts

@@ -22,6 +22,7 @@ import {NgControl} from './ng_control';
 import {normalizeAsyncValidator, normalizeValidator} from './normalize_validator';
 import {NumberValueAccessor} from './number_value_accessor';
 import {RadioControlValueAccessor} from './radio_control_value_accessor';
+import {RangeValueAccessor} from './range_value_accessor';
 import {FormArrayName} from './reactive_directives/form_group_name';
 import {SelectControlValueAccessor} from './select_control_value_accessor';
 import {SelectMultipleControlValueAccessor} from './select_multiple_control_value_accessor';
@@ -130,6 +131,7 @@ export function isPropertyUpdated(changes: {[key: string]: any}, viewModel: any)
 export function isBuiltInAccessor(valueAccessor: ControlValueAccessor): boolean {
   return (
       hasConstructor(valueAccessor, CheckboxControlValueAccessor) ||
+      hasConstructor(valueAccessor, RangeValueAccessor) ||
       hasConstructor(valueAccessor, NumberValueAccessor) ||
       hasConstructor(valueAccessor, SelectControlValueAccessor) ||
       hasConstructor(valueAccessor, SelectMultipleControlValueAccessor) ||

modules/@angular/forms/test/reactive_integration_spec.ts

@@ -22,11 +22,26 @@ export function main() {
       TestBed.configureTestingModule({
         imports: [FormsModule, ReactiveFormsModule],
         declarations: [
-          FormControlComp, FormGroupComp, FormArrayComp, FormArrayNestedGroup,
-          FormControlNameSelect, FormControlNumberInput, FormControlRadioButtons, WrappedValue,
-          WrappedValueForm, MyInput, MyInputForm, FormGroupNgModel, FormControlNgModel,
-          LoginIsEmptyValidator, LoginIsEmptyWrapper, ValidationBindingsForm, UniqLoginValidator,
-          UniqLoginWrapper, NestedFormGroupComp
+          FormControlComp,
+          FormGroupComp,
+          FormArrayComp,
+          FormArrayNestedGroup,
+          FormControlNameSelect,
+          FormControlNumberInput,
+          FormControlRangeInput,
+          FormControlRadioButtons,
+          WrappedValue,
+          WrappedValueForm,
+          MyInput,
+          MyInputForm,
+          FormGroupNgModel,
+          FormControlNgModel,
+          LoginIsEmptyValidator,
+          LoginIsEmptyWrapper,
+          ValidationBindingsForm,
+          UniqLoginValidator,
+          UniqLoginWrapper,
+          NestedFormGroupComp
         ]
       });
     });
@@ -1072,6 +1087,57 @@ export function main() {
 
       });
 
+      describe('should support <type=range>', () => {
+        it('with basic use case', () => {
+          const fixture = TestBed.createComponent(FormControlRangeInput);
+          const control = new FormControl(10);
+          fixture.componentInstance.control = control;
+          fixture.detectChanges();
+
+          // model -> view
+          const input = fixture.debugElement.query(By.css('input'));
+          expect(input.nativeElement.value).toEqual('10');
+
+          input.nativeElement.value = '20';
+          dispatchEvent(input.nativeElement, 'input');
+
+          // view -> model
+          expect(control.value).toEqual(20);
+        });
+
+        it('when value is cleared in the UI', () => {
+          const fixture = TestBed.createComponent(FormControlNumberInput);
+          const control = new FormControl(10, Validators.required);
+          fixture.componentInstance.control = control;
+          fixture.detectChanges();
+
+          const input = fixture.debugElement.query(By.css('input'));
+          input.nativeElement.value = '';
+          dispatchEvent(input.nativeElement, 'input');
+
+          expect(control.valid).toBe(false);
+          expect(control.value).toEqual(null);
+
+          input.nativeElement.value = '0';
+          dispatchEvent(input.nativeElement, 'input');
+
+          expect(control.valid).toBe(true);
+          expect(control.value).toEqual(0);
+        });
+
+        it('when value is cleared programmatically', () => {
+          const fixture = TestBed.createComponent(FormControlNumberInput);
+          const control = new FormControl(10);
+          fixture.componentInstance.control = control;
+          fixture.detectChanges();
+
+          control.setValue(null);
+
+          const input = fixture.debugElement.query(By.css('input'));
+          expect(input.nativeElement.value).toEqual('');
+        });
+      });
+
       describe('custom value accessors', () => {
         it('should support basic functionality', () => {
           const fixture = TestBed.createComponent(WrappedValueForm);
@@ -1798,6 +1864,16 @@ class FormControlNumberInput {
   control: FormControl;
 }
 
+@Component({
+  selector: 'form-control-range-input',
+  template: `
+    <input type="range" [formControl]="control">
+  `
+})
+class FormControlRangeInput {
+  control: FormControl;
+}
+
 @Component({
   selector: 'form-control-radio-buttons',
   template: `

modules/@angular/forms/test/template_integration_spec.ts

@@ -20,7 +20,7 @@ export function main() {
       TestBed.configureTestingModule({
         declarations: [
           StandaloneNgModel, NgModelForm, NgModelGroupForm, NgModelValidBinding, NgModelNgIfForm,
-          NgModelRadioForm, NgModelSelectForm, NgNoFormComp, InvalidNgModelNoName,
+          NgModelRadioForm, NgModelRangeForm, NgModelSelectForm, NgNoFormComp, InvalidNgModelNoName,
           NgModelOptionsStandalone, NgModelCustomComp, NgModelCustomWrapper,
           NgModelValidationBindings, NgModelMultipleValidators
         ],
@@ -480,6 +480,26 @@ export function main() {
 
     });
 
+    describe('range control', () => {
+      it('should support <type=range>', fakeAsync(() => {
+           const fixture = TestBed.createComponent(NgModelRangeForm);
+           // model -> view
+           fixture.componentInstance.val = 4;
+           fixture.detectChanges();
+           tick();
+           let input = fixture.debugElement.query(By.css('input'));
+           expect(input.nativeElement.value).toBe('4');
+           fixture.detectChanges();
+           tick();
+           let newVal = '4';
+           input.triggerEventHandler('input', {target: {value: newVal}});
+           tick();
+           // view -> model
+           fixture.detectChanges();
+           expect(typeof(fixture.componentInstance.val)).toBe('number');
+         }));
+    });
+
     describe('radio controls', () => {
       it('should support <type=radio>', fakeAsync(() => {
            const fixture = TestBed.createComponent(NgModelRadioForm);
@@ -1000,6 +1020,11 @@ class NgModelOptionsStandalone {
   two: string;
 }
 
+@Component({selector: 'ng-model-range-form', template: '<input type="range" [(ngModel)]="val">'})
+class NgModelRangeForm {
+  val: any;
+}
+
 @Component({
   selector: 'ng-model-radio-form',
   template: `