Dart Frog 教程 第2部分：构建你的第一个真实 REST API（完整 CRUD 与 Todos） 🐸

Source: Dev.to

规划与最佳实践

Quick plan – 我们将创建一个包含 id、title 和 completed 状态的 Todo 模型，存储在内存中（使用 Map 进行快速查找）。这使示例保持简洁，同时以后可以轻松替换为真实数据库。

Best practices

• 使用 [id].dart 的动态路由
• 使用 uuid 包生成唯一 ID
• 验证 JSON 请求体
• 返回适当的 HTTP 状态码：200、201、204、400、404、405

设置

添加 UUID 依赖

# pubspec.yaml
dependencies:
  uuid: ^4.5.0

运行包管理器：

dart pub get   # or flutter pub get

Todo 模型

Create lib/src/todo.dart:

/// Represents a Todo item.
class Todo {
  /// Creates a new Todo.
  Todo({
    required this.id,
    required this.title,
    this.isCompleted = false,
  });

  /// Creates a Todo from a JSON map.
  factory Todo.fromJson(Map json) => Todo(
        id: json['id'] as String,
        title: json['title'] as String,
        isCompleted: json['isCompleted'] as bool? ?? false,
      );

  /// Unique identifier.
  final String id;

  /// Title of the todo.
  final String title;

  /// Completion status.
  bool isCompleted;

  /// Converts the Todo to JSON.
  Map toJson() => {
        'id': id,
        'title': title,
        'isCompleted': isCompleted,
      };
}

内存存储

import 'package:my_project/src/todo.dart';
import 'package:uuid/uuid.dart';

const _uuid = Uuid();
final _todos = {};

/// Returns all todos.
List getAllTodos() => _todos.values.toList();

/// Returns a todo by its [id] or `null` if not found.
Todo? getTodoById(String id) => _todos[id];

/// Creates a new todo with the given [title].
void createTodo(String title) {
  final id = _uuid.v4();
  _todos[id] = Todo(id: id, title: title);
}

/// Updates an existing todo.
void updateTodo(String id, {String? title, bool? isCompleted}) {
  final todo = _todos[id];
  if (todo == null) return;
  _todos[id] = Todo(
    id: id,
    title: title ?? todo.title,
    isCompleted: isCompleted ?? todo.isCompleted,
  );
}

/// Deletes a todo.
void deleteTodo(String id) => _todos.remove(id);

路由

集合路由 – routes/todos/index.dart

import 'package:dart_frog/dart_frog.dart';
import 'package:my_project/src/todo_repository.dart';

Future onRequest(RequestContext context) async {
  switch (context.request.method) {
    case HttpMethod.get:
      final todos = getAllTodos();
      return Response.json(
        body: todos.map((e) => e.toJson()).toList(),
      );

    case HttpMethod.post:
      final body = await context.request.json() as Map;
      final title = body['title'] as String?;
      if (title == null || title.isEmpty) {
        return Response(statusCode: 400, body: 'Title is required');
      }
      createTodo(title);
      return Response(statusCode: 201, body: 'Todo created');

    default:
      return Response(statusCode: 405);
  }
}

动态项目路由 – routes/todos/[id].dart

import 'package:dart_frog/dart_frog.dart';
import 'package:my_project/src/todo_repository.dart';

Future onRequest(RequestContext context, String id) async {
  final todo = getTodoById(id);
  if (todo == null) return Response(statusCode: 404);

  switch (context.request.method) {
    case HttpMethod.get:
      return Response.json(body: todo.toJson());

    case HttpMethod.put:
      final body = await context.request.json() as Map;
      final title = body['title'] as String?;
      final isCompleted = body['isCompleted'] as bool?;
      updateTodo(id, title: title, isCompleted: isCompleted);
      return Response.json(body: getTodoById(id)!.toJson());

    case HttpMethod.delete:
      deleteTodo(id);
      return Response(statusCode: 204);

    default:
      return Response(statusCode: 405);
  }
}

测试

快速 curl 示例：

# Get all todos
curl http://localhost:8080/todos

# Create a new todo
curl -X POST http://localhost:8080/todos \
  -H "Content-Type: application/json" \
  -d '{"title": "Learn Dart Frog"}'

# Get a specific todo (replace <id> with the actual id)
curl http://localhost:8080/todos/<id>

API 能够优雅地处理错误，并提供坚实的生产就绪基础。

源代码

通过给仓库加星并关注作者来表达一点 ❤️：
https://github.com/techwithsam/dart_frog_full_course_tutorial

这是你的第一个真正的 Dart Frog REST API —— 恭喜！接下来：将 Flutter 应用连接到它。