23 lines
685 B
TypeScript
23 lines
685 B
TypeScript
import {isString, isBlank} from 'angular2/src/facade/lang';
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import {Injectable, PipeTransform, WrappedValue, Pipe} from 'angular2/core';
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import {InvalidPipeArgumentException} from './invalid_pipe_argument_exception';
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/**
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* Transforms text to lowercase.
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*
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* ### Example
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*
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* {@example core/pipes/ts/lowerupper_pipe/lowerupper_pipe_example.ts region='LowerUpperPipe'}
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*/
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@Pipe({name: 'lowercase'})
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@Injectable()
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export class LowerCasePipe implements PipeTransform {
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transform(value: string): string {
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if (isBlank(value)) return value;
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if (!isString(value)) {
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throw new InvalidPipeArgumentException(LowerCasePipe, value);
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}
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return value.toLowerCase();
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}
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}
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