import 'dart:convert'; import 'package:flutter/cupertino.dart'; import 'package:flutter/material.dart'; import 'package:http/http.dart'; import '../../../models/part.dart'; import '../../../models/user.dart'; import '../../api_routes/urls.dart'; class PartsProvider extends ChangeNotifier { // number of items call in each request final pageItemNumber = 50; //reset provider data void reset() { _parts = null; _stateCode = null; } // state code of current request to defied error message // like 400 customer request failed // 500 service not available int? _stateCode; int? get stateCode => _stateCode; // true if there is next page in product list and false if not bool _nextPage = true; bool get nextPage => _nextPage; // contain user data // when user not login or register _user = null List? _parts; List? get parts => _parts; // when categories in-process _loading = true // done _loading = true // failed _loading = false bool? _loading; bool? get isLoading => _loading; set isLoading(bool? isLoading) { _loading = isLoading; notifyListeners(); } /// 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 getParts({ required String host, required User user, required String? title, }) async { if (_loading == true) return -2; _loading = true; notifyListeners(); Response response; try { response = await get( Uri.parse( "$host${URLs.getPartNumber}?page=${(_parts?.length ?? 0) ~/ pageItemNumber}${title == null || title.isEmpty ? "" : "&name=$title"}", ), headers: {"Content-Type": "application/json; charset=utf-8"}, ); _stateCode = response.statusCode; if (response.statusCode >= 200 && response.statusCode < 300) { // client's request was successfully received List categoriesListJson = json.decode(utf8.decode(response.bodyBytes)); List page = categoriesListJson.map((part) => Part.fromJson(part)).toList(); if (parts == null) _parts = []; _parts?.addAll(page); if (page.length >= pageItemNumber) { _nextPage = true; } else { _nextPage = false; } } _loading = false; notifyListeners(); return response.statusCode; } catch (error) { _loading = false; _stateCode = -1; notifyListeners(); return -1; } } /// return -2 if request in progress /// return -1 if error happen when sending request /// return state code if request complete may be 200, 404 or 403 /// for more details check http state manager /// lib\controllers\http_status_manger\http_status_manger.dart Future> getPartsList({ required String host, required User user, required String? title, }) async { Response response; try { response = await get( Uri.parse(host + URLs.getPartNumber + (title == null || title.isEmpty ? "" : "?name=$title")), headers: {"Content-Type": "application/json; charset=utf-8"}); List page = []; if (response.statusCode >= 200 && response.statusCode < 300) { // client's request was successfully received List categoriesListJson = json.decode(utf8.decode(response.bodyBytes)); page = categoriesListJson.map((part) => Part.fromJson(part)).toList(); } return page; } catch (error) { return []; } } }