import 'dart:convert'; import 'package:flutter/cupertino.dart'; import 'package:http/http.dart'; import '../../../models/department.dart'; import '../../api_routes/urls.dart'; class DepartmentsProvider extends ChangeNotifier { //reset provider data void reset() { departments = null; stateCode = null; } // state code of current request to defied error message // like 400 customer request failed // 500 service not available int? stateCode; // contain user data // when user not login or register _user = null List? departments; // when categories in-process _loading = true // done _loading = true // failed _loading = false bool? isLoading; /// return -2 if request in progress /// return -1 if error happen when sending request /// return state code if request complete may be 200, 404 or 403 /// for more details check http state manager /// lib\controllers\http_status_manger\http_status_manger.dart Future getDepartment(String host) async { if (isLoading == true) { return -2; } isLoading = true; notifyListeners(); Response response; try { response = await get( Uri.parse(host + URLs.getDepartments), headers: {"Content-Type": "application/json; charset=utf-8"}, ); } catch (error) { isLoading = false; stateCode = -1; notifyListeners(); return -1; } stateCode = response.statusCode; if (response.statusCode >= 200 && response.statusCode < 300) { // client's request was successfully received List listJson = json.decode(utf8.decode(response.bodyBytes).replaceAll("\\", "")); departments = listJson.map((department) => Department.fromJson(department)).toList(); } isLoading = false; notifyListeners(); return response.statusCode; } }