angular-docs-cn/packages/forms/src/directives/number_value_accessor.ts
Miško Hevery 6649743a2d fix(forms): Update types for TypeScript nullability support
This reverts commit 2e47a0d19fa1d1527cf998d87cd8a49bc968606a.
2017-04-14 15:10:26 -07:00

59 lines
1.9 KiB
TypeScript

/**
* @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, Renderer, forwardRef} 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
};
/**
* The accessor for writing a number value and listening to changes that is used by the
* {@link NgModel}, {@link FormControlDirective}, and {@link FormControlName} directives.
*
* ### Example
* ```
* <input type="number" [(ngModel)]="age">
* ```
*/
@Directive({
selector:
'input[type=number][formControlName],input[type=number][formControl],input[type=number][ngModel]',
host: {
'(change)': 'onChange($event.target.value)',
'(input)': 'onChange($event.target.value)',
'(blur)': 'onTouched()'
},
providers: [NUMBER_VALUE_ACCESSOR]
})
export class NumberValueAccessor implements ControlValueAccessor {
onChange = (_: any) => {};
onTouched = () => {};
constructor(private _renderer: Renderer, private _elementRef: ElementRef) {}
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.setElementProperty(this._elementRef.nativeElement, 'value', normalizedValue);
}
registerOnChange(fn: (_: number|null) => 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);
}
}