range_value_accessor.ts
/**
* @license
* Copyright Google LLC 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, forwardRef, Provider} from '@angular/core';
import {BuiltInControlValueAccessor, ControlValueAccessor, NG_VALUE_ACCESSOR} from './control_value_accessor';
const RANGE_VALUE_ACCESSOR: Provider = {
provide: NG_VALUE_ACCESSOR,
useExisting: forwardRef(() => RangeValueAccessor),
multi: true
};
/**
* @description
* The `ControlValueAccessor` for writing a range value and listening to range input changes.
* The value accessor is used by the `FormControlDirective`, `FormControlName`, and `NgModel`
* directives.
*
* @usageNotes
*
* ### Using a range input with a reactive form
*
* The following example shows how to use a range input with a reactive form.
*
* ```ts
* const ageControl = new FormControl();
* ```
*
* ```
* <input type="range" [formControl]="ageControl">
* ```
*
* @ngModule ReactiveFormsModule
* @ngModule FormsModule
* @publicApi
*/
@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 extends BuiltInControlValueAccessor implements
ControlValueAccessor {
/**
* Sets the "value" property on the input element.
* @nodoc
*/
writeValue(value: any): void {
this.setProperty('value', parseFloat(value));
}
/**
* Registers a function called when the control value changes.
* @nodoc
*/
override registerOnChange(fn: (_: number|null) => void): void {
this.onChange = (value) => {
fn(value == '' ? null : parseFloat(value));
};
}
}