Access up to the "model" key parameter in my listview builder for the provided json format in flutter - json

Question

I want to access up to the "model" key parameter in my listview builder for the provided json format in flutter but I don't know how can I access them
I want to access the child object model
What the json will look like:
[
{
"vehicle": "roadways",
"id": "10000",
"category": {
"500": {
"id": "500",
"name": "Bike",
"icon": "http://example.com/bike.jpg",
"model": [
{
"id": "510",
"name": "Harley"
},
{
"id": "520",
"name": "Kawasaki"
}
]
},
"50": {
"id": "50",
"name": "Car",
"icon": "http://example.com/car.jpg",
}
},
},
{
"vehicle": "waterways",
"id": "20000",
"category": {
"600": {
"id": "600",
"name": "Ship",
"icon": "http://example.com/ship.jpg",
"model": [
{
"id": "610",
"name": "model_1"
},
{
"id": "520",
"name": "model_2"
}
]
},
"700": {
"id": "700",
"name": "model_3",
"icon": "http://example.com/car.jpg",
}
},
}
]

Answer 1

var data = jsonDecode("yourJosnString");
ListView.builder(
itemCount: data.length,
itemBuilder: (context, i) {
var data1 = data[i]["category"];
String firstKey = data1.keys.first;
var model = data1[firstKey];
return Column(
children: [
for (i = 0; i < model.length; i++) ...[
Text(
model["name"],
)
]
],
);
},
),

Answer 2

you should first make an object for this json, like this:
class Vehicle {
final String name;
final VehicleCategory category;
Vehicle({#required this.name, #required this.category});
static List<Vehicle> fromJson(List _list) {
List<Vehicle> result = [];
for (var item in _list) {
var address = Vehicle(
name: item['id'] as String,
category: VehicleCategory.fromJson(
item['category']['500'] as Map<String, Object> ?? {}),
);
result.add(address);
}
return result;
}
}
class VehicleCategory {
final String name;
final String icon;
final List<VehicleModel> model;
VehicleCategory(
{#required this.name, #required this.icon, #required this.model});
static VehicleCategory fromJson(Map<String, Object> _json) {
return VehicleCategory(
name: _json['name'] as String ?? '',
icon: _json['icon'] as String ?? '',
model:
VehicleModel.fromJson(_json['model'] as List ?? []));
}
}
class VehicleModel {
final String name;
final String id;
VehicleModel({#required this.name, #required this.id});
static List<VehicleModel> fromJson(List _list) {
List<VehicleModel> result = [];
for (var item in _list) {
var address = VehicleModel(
name: item['name'] as String,
id: item['id'] as String,
);
result.add(address);
}
return result;
}
}
then use it like this:
List<Vehicle> _list = Vehicle.fromJson(_myJson);
return ListView.builder(
itemCount: _list.length,
itemBuilder: (context, i) {
return Column(
children: [
ListView.builder(
itemCount: _list[i].category.model.length,
itemBuilder: (context, j) {
return Text(_list[i].category.model[j].name);
},
)
],
);
},
);