i18n_plural_pipe.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 {Pipe, PipeTransform} from '@angular/core';
import {getPluralCategory, NgLocalization} from '../i18n/localization';
import {invalidPipeArgumentError} from './invalid_pipe_argument_error';
const _INTERPOLATION_REGEXP: RegExp = /#/g;
/**
* @ngModule CommonModule
* @description
*
* Maps a value to a string that pluralizes the value according to locale rules.
*
* @usageNotes
*
* ### Example
*
* {@example common/pipes/ts/i18n_pipe.ts region='I18nPluralPipeComponent'}
*
* @publicApi
*/
@Pipe({name: 'i18nPlural', pure: true})
export class I18nPluralPipe implements PipeTransform {
constructor(private _localization: NgLocalization) {}
/**
* @param value the number to be formatted
* @param pluralMap an object that mimics the ICU format, see
* http://userguide.icu-project.org/formatparse/messages.
* @param locale a `string` defining the locale to use (uses the current {@link LOCALE_ID} by
* default).
*/
transform(value: number, pluralMap: {[count: string]: string}, locale?: string): string {
if (value == null) return '';
if (typeof pluralMap !== 'object' || pluralMap === null) {
throw invalidPipeArgumentError(I18nPluralPipe, pluralMap);
}
const key = getPluralCategory(value, Object.keys(pluralMap), this._localization, locale);
return pluralMap[key].replace(_INTERPOLATION_REGEXP, value.toString());
}
}