Parsing json List in flutter dart

import 'dart:convert';

import 'package:flutter/material.dart';

void main() {
  runApp(
    const MaterialApp(
      home: HomePage(),
    ),
  );
}

class HomePage extends StatefulWidget {
  const HomePage({super.key});

  @override
  State<HomePage> createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  List<DataModel> data = [
    {
      'id': 6,
      'owner': {
        'username': 'ghazali',
        'email': '[email protected]',
        'first_name': 'Abu',
        'last_name': 'Ubaidah',
        'groups': [],
      },
      'name': 'Food Hub',
      'date_created': '2023-12-27T20:13:13.414637Z',
    }.dataModel,
    {
      'id': 7,
      'owner': {
        'username': 'ghazali',
        'email': '[email protected]',
        'first_name': 'Abu',
        'last_name': 'Ubaidah',
        'groups': [],
      },
      'name': 'Hamas',
      'date_created': '2023-12-27T20:04:56.852096Z',
    }.dataModel,
  ];
  @override
  Widget build(BuildContext context) {
    return Scaffold(
        body: ListView.builder(
      itemCount: data.length,
      itemBuilder: (context, index) {
        return OrganizationCard(
          id: data[index].id,
          tagLine: "We'll find the best for you.",
          name: data[index].name,
        );
      },
    ));
  }
}

extension CustomExtension on Map<String, dynamic> {
  DataModel get dataModel => DataModel.fromMap(this);
}

class DataModel {
  final int id;
  final Owner owner;
  final String name;
  final String dataCreated;

  DataModel(this.id, this.owner, this.name, this.dataCreated);

  Map<String, dynamic> toMap() {
    return <String, dynamic>{
      'id': id,
      'owner': owner.toMap(),
      'name': name,
      'date_created': dataCreated,
    };
  }

  factory DataModel.fromMap(Map<String, dynamic> map) {
    return DataModel(
      map['id'] as int,
      Owner.fromMap(map['owner'] as Map<String, dynamic>),
      map['name'] as String,
      map['date_created'] as String,
    );
  }

  String toJson() => json.encode(toMap());

  factory DataModel.fromJson(String source) =>
      DataModel.fromMap(json.decode(source) as Map<String, dynamic>);
}

class Owner {
  final String username;
  final String email;
  final String firstName;
  final String lastName;
  final List<dynamic> groups;

  Owner(this.username, this.email, this.firstName, this.lastName, this.groups);

  Map<String, dynamic> toMap() {
    return <String, dynamic>{
      'username': username,
      'email': email,
      'first_name': firstName,
      'last_name': lastName,
      'groups': groups,
    };
  }

  factory Owner.fromMap(Map<String, dynamic> map) {
    return Owner(
        map['username'] as String,
        map['email'] as String,
        map['first_name'] as String,
        map['last_name'] as String,
        List<dynamic>.from(
          (map['groups'] as List<dynamic>),
        ));
  }

  String toJson() => json.encode(toMap());

  factory Owner.fromJson(String source) =>
      Owner.fromMap(json.decode(source) as Map<String, dynamic>);
}

class OrganizationCard extends StatelessWidget {
  final int id;
  final String tagLine;
  final String name;
  const OrganizationCard({
    Key? key,
    required this.id,
    required this.tagLine,
    required this.name,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return ListTile(
      leading: Text(id.toString()),
      title: Text(name),
      subtitle: Text(tagLine),
    );
  }
}