import {Toast} from "native-base"; export default class WebDataManager { FETCH_URL : string; lastDataFetched : Object = {}; constructor(url) { this.FETCH_URL = url; } async readData() { let fetchedData : Object = {}; try { let response = await fetch(this.FETCH_URL); fetchedData = await response.json(); } catch (error) { console.log('Could not read FetchedData from server'); console.log(error); } this.lastDataFetched = fetchedData; return fetchedData; } isDataObjectValid() { return Object.keys(this.lastDataFetched).length > 0; } showUpdateToast(successString, errorString) { let isSuccess = this.isDataObjectValid(); if (!isSuccess) { Toast.show({ text: isSuccess ? successString : errorString, buttonText: 'OK', type: isSuccess ? "success" : "danger", duration: 2000 }); } } }