33 lines
854 B
TypeScript
33 lines
854 B
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 {Pipe, PipeTransform} from '@angular/core';
|
|
import {isBlank, isString} from '../facade/lang';
|
|
import {InvalidPipeArgumentException} from './invalid_pipe_argument_exception';
|
|
|
|
|
|
/**
|
|
* Transforms text to lowercase.
|
|
*
|
|
* ### Example
|
|
*
|
|
* {@example core/pipes/ts/lowerupper_pipe/lowerupper_pipe_example.ts region='LowerUpperPipe'}
|
|
*
|
|
* @stable
|
|
*/
|
|
@Pipe({name: 'lowercase'})
|
|
export class LowerCasePipe implements PipeTransform {
|
|
transform(value: string): string {
|
|
if (isBlank(value)) return value;
|
|
if (!isString(value)) {
|
|
throw new InvalidPipeArgumentException(LowerCasePipe, value);
|
|
}
|
|
return value.toLowerCase();
|
|
}
|
|
}
|