OpenSlides/client/src/app/core/pruning-loader.ts
2018-11-01 11:22:41 +01:00

57 lines
2.0 KiB
TypeScript

import { TranslateLoader } from '@ngx-translate/core';
import { HttpClient } from '@angular/common/http';
import { map } from 'rxjs/operators/';
import { Observable } from 'rxjs';
/**
* Translation loader that replaces empty strings with nothing.
*
* ngx-translate-extract writes empty strings into json files.
* The problem is that these empty strings don't trigger
* the MissingTranslationHandler - they are simply empty strings...
*
*/
export class PruningTranslationLoader implements TranslateLoader {
/**
* Constructor to load the HttpClient
*
* @param http httpClient to load the translation files.
* @param prefix Path to the language files. Can be adjusted of needed
* @param suffix Suffix of the translation files. Usually '.json'.
*/
public constructor(
private http: HttpClient,
private prefix: string = '/assets/i18n/',
private suffix: string = '.json'
) {}
/**
* Loads a language file, stores the content, give it to the process function.
* @param lang language string (en, fr, de, ...)
*/
public getTranslation(lang: string): Observable<any> {
return this.http.get(`${this.prefix}${lang}${this.suffix}`).pipe(map((res: Object) => this.process(res)));
}
/**
* Prevent to display empty strings as a translation.
* Falls back to the default language or simply copy the content of the key.
* @param any the content of any language file.
*/
private process(object: any): any {
const newObject = {};
for (const key in object) {
if (object.hasOwnProperty(key)) {
if (typeof object[key] === 'object') {
newObject[key] = this.process(object[key]);
} else if (typeof object[key] === 'string' && object[key] === '') {
// do not copy empty strings
} else {
newObject[key] = object[key];
}
}
}
return newObject;
}
}