购物车页面的 Flutter Provider

Question

I need to make a cart page for an e-commerce app. where I am getting JSON data from API. I can fetch the data and show data. but when it's matter to cart I cannot add this data to my provider page.

This is MY Provider Page For Album

import 'package:flutter/material.dart';
import 'package:provider_test/albumModel.dart';
import '../Service/service.dart';

class MyStore extends ChangeNotifier {
  List<Album> _albums = [];
  List<Album> _busket = [];
  Album _activeAlbum = null;

  List<Album> get albums => _albums;
  List<Album> get buskets => _busket;
  Album get activeAlbum => _activeAlbum;
}

And this is my Album Model Page:

 import 'dart:convert';

import 'package:flutter/cupertino.dart';

List<Album> allalbumsFromJson(String str) {
  final jsonData = json.decode(str);
  return new List<Album>.from(jsonData.map((x) => Album.fromJson(x)));
} //ef

class AlbumList with ChangeNotifier {
  final List<Album> albums;

  AlbumList({
this.albums,
  });

  factory AlbumList.fromJson(List<dynamic> parsedJson) {
List<Album> albums = List<Album>();
albums = parsedJson.map((i) => Album.fromJson(i)).toList();

return AlbumList(albums: albums);
  }
  notifyListeners();
} //ef

class Album with ChangeNotifier {
  int userId;
  int id;
  String title;

  Album({this.userId, this.id, this.title});

  Album.fromJson(Map<String, dynamic> json) {
userId = json['userId'];
id = json['id'];
title = json['title'];
  }
  notifyListeners();
} //ef

Album albumFromJson(String str) {
final jsonData = json.decode(str);
return Album.fromJson(jsonData);
    } //ef

Now I can fetch Data Using this Function:

import 'package:flutter/cupertino.dart';
import 'package:provider_test/albumModel.dart';
import 'package:http/http.dart' as HTTP;

final url = ('https://jsonplaceholder.typicode.com/albums');

Future<List<Album>> getAllAlbum() async {
  final response = await http.get(url);
  // print(response.body);
  return allalbumsFromJson(response.body);
}

Future<Album> getAlbum() async {
  final response = await http.get('$url/1');
 return albumFromJson(response.body);
}

How Can I insert getAllAlbums() Data or you can say List Data into the _albums=[] which is situated in Mystore Page?

Answer 1

Hi for the cart I think you the best way you must use a map instead of a list like below:

  Map<int, FavoriteModel> _favoites = {};

  Map<int, FavoriteModel> get favoitesItem {
    return _favoites;
  }

And for adding data from you can use of this method:

  void addOrRemoveSingleItem({
    int foodId,
    String title,
    double price,
    String imageUrl,
    int userId
  }) async {
    if (_favoites.containsKey(foodId)) {
      try {
        final res = await http.post(
          addFavoriteUrl,
          body: {
            "user_id": userId.toString(),
            "food_id": foodId.toString(),
            "Is_delete": "1",
          },
        );
      } catch (e) {
        print(e);
        throw (e);
      }
    } else {
      try {
        _favoites.putIfAbsent(
          foodId,
          () => FavoriteModel(
            id: foodId,
            name: title,
            regularPrice: price,
            featureImage: imageUrl,
          ),
        );
        http.post(
          addFavoriteUrl,
          body: {
            "user_id": userId.toString(),
            "food_id": foodId.toString(),
          },
        );
      } catch (e) {
        print(e);
        throw (e);
      }
    }
    notifyListeners();
  }