Not getting required value from json list - flutter - json

Question

I have this code where am able to get values from an online json data and print its value
main.dart
final String url = 'https://raw.githubusercontent.com/BrightCode1/ohms-json/master/categories.json';
List<JsonModel> myModel = [];
List<CatSubcategory> subCate = [];
int localInt;
#override
void initState() {
// TODO: implement initState
super.initState();
localInt = 0;
loadData(localInt);
}
loadData(int dataInt) async {
var res = await http.get(url, headers: {"Accept": "application/json"});
if (res.statusCode == 200) {
String resBody = res.body;
var jsonDecode = json.decode(resBody);
for (var data in jsonDecode) {
data['cat_subcategory'].map((x) {
return subCate.add(
CatSubcategory(subName: x['sub_name'], subImage: x['sub_image']));
}).toList();
myModel.add(JsonModel(
category: data['category'],
catId: data['cat_id'],
catIcon: data['cat_icon'],
catSubcategory: subCate));
setState(() {});
}
print(myModel[dataInt].catSubcategory.length);
} else {
print("Something went wrong!");
}
}
my model.dart
class JsonModel {
JsonModel({
this.category,
this.catId,
this.catIcon,
this.catSubcategory,
});
String category;
String catId;
String catIcon;
List<CatSubcategory> catSubcategory;
factory JsonModel.fromJson(Map<String, dynamic> json) => JsonModel(
category: json["category"],
catId: json["cat_id"],
catIcon: json["cat_icon"],
catSubcategory: List<CatSubcategory>.from(
json["cat_subcategory"].map((x) => CatSubcategory.fromJson(x))),
);
Map<String, dynamic> toJson() => {
"category": category,
"cat_id": catId,
"cat_icon": catIcon,
"cat_subcategory":
List<dynamic>.from(catSubcategory.map((x) => x.toJson())),
};
}
class CatSubcategory {
CatSubcategory({
this.subName,
this.subImage,
});
String subName;
String subImage;
factory CatSubcategory.fromJson(Map<String, dynamic> json) => CatSubcategory(
subName: json["sub_name"],
subImage: json["sub_image"],
);
Map<String, dynamic> toJson() => {
"sub_name": subName,
"sub_image": subImage,
};
}
The only problem am having now is that when I try to print the length on the subcategory of the first list it gives me 24 instead of 6 and i printed it like this myModel[dataInt].catSubcategory.length. The dataInt is 0 which means it's supposed to print out the length of the children("cat_subcategory") with category of Design & Creativity but it's printing all the other children of the other lis. So please how do i go about this. And if you need more explanation tell me

Answer 1

I would avoid writing your own model from scratch if you already know the schema of your json.
Just use something like https://app.quicktype.io/ just paste your json and you will get
import 'dart:convert';
class Root {
Root({
this.category,
this.catId,
this.catIcon,
this.catSubcategory,
});
String category;
String catId;
String catIcon;
List<CatSubcategory> catSubcategory;
factory Root.fromJson(Map<String, dynamic> json) => Root(
category: json["category"],
catId: json["cat_id"],
catIcon: json["cat_icon"] == null ? null : json["cat_icon"],
catSubcategory: List<CatSubcategory>.from(json["cat_subcategory"].map((x) => CatSubcategory.fromJson(x))),
);
Map<String, dynamic> toJson() => {
"category": category,
"cat_id": catId,
"cat_icon": catIcon == null ? null : catIcon,
"cat_subcategory": List<dynamic>.from(catSubcategory.map((x) => x.toJson())),
};
}
class CatSubcategory {
CatSubcategory({
this.subName,
this.subImage,
});
String subName;
String subImage;
factory CatSubcategory.fromJson(Map<String, dynamic> json) => CatSubcategory(
subName: json["sub_name"],
subImage: json["sub_image"],
);
Map<String, dynamic> toJson() => {
"sub_name": subName,
"sub_image": subImage,
};
}
and then you should be good to just
loadData(int dataInt) async {
var res = await http.get(url, headers: {"Accept": "application/json"});
if (res.statusCode == 200) {
String resBody = res.body;
var list = json.decode(resBody) as List;
List<Root> items = list.map((i)=>Root.fromJson(i)).toList();
print(items[0].catSubcategory.length);
}
} else {
print("Something went wrong!");
}
}
https://repl.it/talk/share/Sample/118111