Write a TODO app in FLutter using a Rest API to read and write data. Encapsulate business logic in a dedicated controller class.

ChatGPT_TodoApp.dart

Write a TODO app in FLutter using a Rest API to read and write data. Encapsulate business logic in a dedicated controller class.

//Imports
import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
import 'dart:convert';

//Todo Controller class
class TodoController {
  //Get all todos
  Future<List> getTodos() async {
    final response = await http.get('https://my-json-server.typicode.com/user/todos');

    if (response.statusCode == 200) {
      List todos = json.decode(response.body);
      return todos;
    } else {
      throw Exception('Failed to load todos');
    }
  }

  //Create a new todo
  Future<bool> createTodo(String title) async {
    Map<String, String> body = {'title': title};
    final response = await http.post('https://my-json-server.typicode.com/user/todos', body: body);

    if (response.statusCode == 201) {
      return true;
    } else {
      return false;
    }
  }

  //Update a todo
  Future<bool> updateTodo(int id, String title) async {
    Map<String, String> body = {'title': title};
    final response = await http.put('https://my-json-server.typicode.com/user/todos/$id', body: body);

    if (response.statusCode == 200) {
      return true;
    } else {
      return false;
    }
  }

  //Delete a todo
  Future<bool> deleteTodo(int id) async {
    final response = await http.delete('https://my-json-server.typicode.com/user/todos/$id');

    if (response.statusCode == 200) {
      return true;
    } else {
      return false;
    }
  }
}

//Todo Model class
class Todo {
  int id;
  String title;
  bool completed;

  Todo({this.id, this.title, this.completed});

  factory Todo.fromJson(Map<String, dynamic> json) {
    return Todo(
      id: json['id'],
      title: json['title'],
      completed: json['completed'],
    );
  }
}

//Todo App class
class TodoApp extends StatefulWidget {
  @override
  _TodoAppState createState() => _TodoAppState();
}

class _TodoAppState extends State<TodoApp> {
  List<Todo> _todos = [];
  TextEditingController _textController = TextEditingController();
  TodoController _todoController = TodoController();

  @override
  void initState() {
    super.initState();
    _loadTodos();
  }

  _loadTodos() async {
    List todos = await _todoController.getTodos();
    setState(() {
      _todos = todos.map((todo) => Todo.fromJson(todo)).toList();
    });
  }

  _createTodo() async {
    String title = _textController.text;
    bool success = await _todoController.createTodo(title);

    if (success) {
      _textController.clear();
      _loadTodos();
    }
  }

  _updateTodo(int id, String title) async {
    bool success = await _todoController.updateTodo(id, title);

    if (success) {
      _loadTodos();
    }
  }

  _deleteTodo(int id) async {
    bool success = await _todoController.deleteTodo(id);

    if (success) {
      _loadTodos();
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Todo App'),
      ),
      body: Column(
        children: <Widget>[
          Padding(
            padding: const EdgeInsets.all(8.0),
            child: TextField(
              controller: _textController,
              decoration: InputDecoration(
                hintText: 'Enter a todo...'
              ),
            ),
          ),
          RaisedButton(
            onPressed: _createTodo,
            child: Text('Add Todo'),
          ),
          Expanded(
            child: ListView.builder(
              itemCount: _todos.length,
              itemBuilder: (BuildContext context, int index) {
                Todo todo = _todos[index];
                return ListTile(
                  title: Text(todo.title),
                  trailing: Row(
                    mainAxisSize: MainAxisSize.min,
                    children: <Widget>[
                      IconButton(
                        icon: Icon(Icons.edit),
                        onPressed: () {
                          _showEditDialog(todo);
                        },
                      ),
                      IconButton(
                        icon: Icon(Icons.delete),
                        onPressed: () {
                          _deleteTodo(todo.id);
                        },
                      ),
                    ],
                  ),
                );
              },
            ),
          ),
        ],
      ),
    );
  }

  _showEditDialog(Todo todo) {
    TextEditingController controller = TextEditingController(text: todo.title);
    showDialog(
      context: context,
      builder: (BuildContext context) {
        return AlertDialog(
          title: Text('Edit Todo'),
          content: TextField(
            controller: controller,
            decoration: InputDecoration(
              hintText: 'Enter a todo...'
            ),
          ),
          actions: <Widget>[
            FlatButton(
              child: Text('Cancel'),
              onPressed: () {
                Navigator.of(context).pop();
              },
            ),
            FlatButton(
              child: Text('Save'),
              onPressed: () {
                _updateTodo(todo.id, controller.text);
                Navigator.of(context).pop();
              },
            ),
          ],
        );
      }
    );
  }
}