I am working on an app where i am getting json response from api. I want to store all the objects coming from api into a list and then i want to show that list in a listview builder wrapped with future builder.

Here is my model `// To parse this JSON data, do
//
//     final viewCategoryModel = viewCategoryModelFromJson(jsonString);

import 'dart:convert';

ViewCategoryModel viewCategoryModelFromJson(String str) =>
    ViewCategoryModel.fromJson(json.decode(str));

String viewCategoryModelToJson(ViewCategoryModel data) =>
    json.encode(data.toJson());

class ViewCategoryModel {
  ViewCategoryModel({
    this.status,
    this.data,
  });

  bool? status;
  List<Datum>? data;

  factory ViewCategoryModel.fromJson(Map<String, dynamic> json) =>
      ViewCategoryModel(
        status: json["status"],
        data: List<Datum>.from(json["data"].map((x) => Datum.fromJson(x))),
      );

  Map<String, dynamic> toJson() => {
        "status": status,
        "data": List<dynamic>.from(data!.map((x) => x.toJson())),
      };
}

class Datum {
  Datum({
    this.categoryName,
    this.categoryCode,
    this.categoryType,
  });

  String? categoryName;
  String? categoryCode;
  String? categoryType;

  factory Datum.fromJson(Map<String, dynamic> json) => Datum(
        categoryName: json["category_name"],
        categoryCode: json["category_code"],
        categoryType: json["category_type"],
      );

  Map<String, dynamic> toJson() => {
        "category_name": categoryName,
        "category_code": categoryCode,
        "category_type": categoryType,
      };
}

` here is json response fromapi

{"status":true,"data":[{"category_name":"new category","category_code":"50","category_type":"Clothing"},{"category_name":"new category","category_code":"51","category_type":"Clothing"},{"category_name":"new category","category_code":"52","category_type":"Clothing"},{"category_name":"new category","category_code":"53","category_type":"Clothing"}]}

Please help

CodePudding user response：

Without the service class you've done 45% of work, I would suggest you go through this Fetch Data from Internet

Meanwhile you could do this:

As the widget name suggests FutureBuilder() it expects a future type of data

///Step one ->Service class

class FetchService{
  ///fetch all flags
  Future<ViewCategoryModel> fetData() async{

    try{
      Response response = await get(
        Uri.parse('your url here'),
        headers: {'Accept': 'application/json'}
      );
      if(response .statusCode == 200 || response.statusCode == 201){
           final viewCategoryModel = viewCategoryModelFromJson(request.body);
          return viewCategoryModel;
      }else{
       final viewCategoryModel = viewCategoryModelFromJson(request.body);
          return viewCategoryModel;
      }
    }catch(e){
      print('Error occurred: $e');
      return Future.error(e);
    }
  }
}

Then getting the data into the FutureBuilder()

...
 ///initialize
  late Future<ViewCategoryModel> viewCategory;

  @override
  void initState() {
    viewCategory = FetchService().fetchData();
    super.initState();
  }

...
 FutureBuilder<ViewCategoryModel>(
                  future: viewCategory,
                  builder: (context, AsyncSnapshot<ViewCategoryModel> snapshot){
    if (snapshot.hasError) {
                      print("Error found ${snapshot.error}");
                      return CircularProgressIndicator();
                    }else if(snapshot.hasData){
                  
                     return SizedBox(
                          height: MediaQuery.of(context).size.height,
                          child:ListView(
                            snapshot.data!.data!.length,(index){
                           return ListTile(
                                title: Text(
                                  snapshot.data!.data![index].category_name
                                      .toString(),
                                ),
                              ),
                     }
                          )
                        );
         }
      }