number_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, ElementRef, forwardRef, Renderer2} from '@angular/core';
import {ControlValueAccessor, NG_VALUE_ACCESSOR} from './control_value_accessor';
export const NUMBER_VALUE_ACCESSOR: any = {
provide: NG_VALUE_ACCESSOR,
useExisting: forwardRef(() => NumberValueAccessor),
multi: true
};
/**
* @description
* The `ControlValueAccessor` for writing a number value and listening to number input changes.
* The value accessor is used by the `FormControlDirective`, `FormControlName`, and `NgModel`
* directives.
*
* @usageNotes
*
* ### Using a number input with a reactive form.
*
* The following example shows how to use a number input with a reactive form.
*
* ```ts
* const totalCountControl = new FormControl();
* ```
*
* ```
* <input type="number" [formControl]="totalCountControl">
* ```
*
* @ngModule ReactiveFormsModule
* @ngModule FormsModule
* @publicApi
*/
@Directive({
selector:
'input[type=number][formControlName],input[type=number][formControl],input[type=number][ngModel]',
host: {'(input)': 'onChange($event.target.value)', '(blur)': 'onTouched()'},
providers: [NUMBER_VALUE_ACCESSOR]
})
export class NumberValueAccessor implements ControlValueAccessor {
/**
* The registered callback function called when a change or input event occurs on the input
* element.
* @nodoc
*/
onChange = (_: any) => {};
/**
* The registered callback function called when a blur event occurs on the input element.
* @nodoc
*/
onTouched = () => {};
constructor(private _renderer: Renderer2, private _elementRef: ElementRef) {}
/**
* Sets the "value" property on the input element.
* @nodoc
*/
writeValue(value: number): void {
// The value needs to be normalized for IE9, otherwise it is set to 'null' when null
const normalizedValue = value == null ? '' : value;
this._renderer.setProperty(this._elementRef.nativeElement, 'value', normalizedValue);
}
/**
* Registers a function called when the control value changes.
* @nodoc
*/
registerOnChange(fn: (_: number|null) => void): void {
this.onChange = (value) => {
fn(value == '' ? null : parseFloat(value));
};
}
/**
* Registers a function called when the control is touched.
* @nodoc
*/
registerOnTouched(fn: () => void): void {
this.onTouched = fn;
}
/**
* Sets the "disabled" property on the input element.
* @nodoc
*/
setDisabledState(isDisabled: boolean): void {
this._renderer.setProperty(this._elementRef.nativeElement, 'disabled', isDisabled);
}
}