import { Pipe, PipeTransform } from '@angular/core'; @Pipe({ name: 'map' }) export class MapPipe implements PipeTransform { transform(input: any, query: any): any { function convertToArray(object) { return Array.isArray(object) ? object : Object.keys(object).map(function (key) { return object[key]; }); } function isObject(object) { return (typeof object === "object" && object !== null) || typeof object === "function"; } input = isObject(input) ? convertToArray(input) : input; if (!Array.isArray(input) || typeof query === undefined) { return input; } return input.map((element) => String(element)); } }