Edge Computing with Cloudflare Workers & Deno · レッスン

RESTful APIの設計

エッジデプロイに適したRESTful APIのエンドポイント、メソッド、データモデルを計画・構成します

「RESTful APIの設計」はCoddyKit上の無料Edge Computing with Cloudflare Workers & Denoレッスンです。これはレッスン1/3です。下記で完全なレッスンを無料で読むことができます。その後、ブラウザ内の組み込みコードエディタと24時間対応のAIチューターでハンズオン演習できます。これはEdge Computing with Cloudflare Workers & Deno学習パスの一部であり、ウェブとCoddyKitアプリ全体で進捗が同期されます。 Edge Computing with Cloudflare Workers & Denoコースには全3レッスンが含まれています。

このレッスンの一部はまだ翻訳されておらず、英語で表示されています。

Intro to RESTful APIs

Welcome! In this lesson, you'll learn about RESTful APIs, a fundamental way to design web services. REST stands for Representational State Transfer.

Think of an API as a menu in a restaurant. You make a request (order food), and the kitchen (server) sends back a response (your meal). REST defines a set of rules for how this communication should happen over the internet.

Core REST Principles

RESTful APIs are built around a few core ideas:

Resources: Everything is a 'resource' (e.g., a user, a product).
Unique URIs: Each resource has a unique address (a URL or URI).
Standard Methods: HTTP methods (GET, POST, PUT, DELETE) are used to perform actions on resources.
Statelessness: Each request from a client to a server must contain all the information needed to understand the request. The server doesn't store client 'session' state between requests.

Resources Are Nouns

When designing your API, think about the 'things' your application manages. These 'things' are your resources.

For example, if you're building an e-commerce API, your resources might include:

/products
/users
/orders
/categories

Notice how these are all plural nouns. This is a common and recommended practice in RESTful design.

HTTP Methods: The Verbs

HTTP methods tell the server what kind of action you want to perform on a resource. They are like verbs in a sentence:

GET: Retrieve data (e.g., get a product, get a list of users).
POST: Create new data (e.g., create a new user, add a new product).
PUT: Update existing data (replaces an entire resource).
PATCH: Partially update existing data (updates specific fields of a resource).
DELETE: Remove data (e.g., delete a product).

GET: Fetching Data Example

The GET method is used to request data from a specified resource. It should never have side effects (i.e., it shouldn't change data on the server).

Try running this simple Deno server. Then open your browser to http://localhost:8000/products to see the output.

import { serve } from "https://deno.land/std/http/server.ts";

serve(async (req) => {
  const url = new URL(req.url);

  if (req.method === "GET" && url.pathname === "/products") {
    const products = [
      { id: 1, name: "Wireless Mouse", price: 25.99 },
      { id: 2, name: "Mechanical Keyboard", price: 79.99 }
    ];
    return new Response(JSON.stringify(products), {
      headers: { "Content-Type": "application/json" }
    });
  }

  return new Response("Not Found", { status: 404 });
}, { port: 8000 });

console.log("Server running on http://localhost:8000");

POST: Creating Data Example

The POST method is used to submit an entity to the specified resource, often causing a change in state or the creation of a new resource.

This example shows how a Deno server can handle a POST request to create a new product. You would typically send JSON data in the request body.

import { serve } from "https://deno.land/std/http/server.ts";

serve(async (req) => {
  const url = new URL(req.url);

  if (req.method === "POST" && url.pathname === "/products") {
    try {
      const newProduct = await req.json();
      // In a real application, you'd save newProduct to a database.
      // For this example, we'll just log it and return a mock ID.
      console.log("Received new product:", newProduct);
      return new Response(JSON.stringify({ ...newProduct, id: 3 }), {
        status: 201, // 201 Created
        headers: { "Content-Type": "application/json" }
      });
    } catch (e) {
      return new Response("Invalid JSON payload", { status: 400 });
    }
  }

  return new Response("Method Not Allowed", { status: 405 });
}, { port: 8000 });

console.log("Server running on http://localhost:8000");

Designing Endpoint Paths

Clear and consistent endpoint paths (URIs) are crucial for a good API. Here are some best practices:

Use plural nouns: /users, not /user.
Avoid verbs in paths: /products is good, /getProducts is not. The HTTP method implies the action.
Nesting for relationships: For related resources, use nesting. E.g., /users/{id}/orders to get orders for a specific user.
Use path parameters for specific resources: /products/{id} to refer to a single product.

Data Models & Payloads

The data you send to and receive from your API is called a payload. In modern RESTful APIs, JSON (JavaScript Object Notation) is the standard format.

A data model defines the structure of this JSON. For example, a 'product' data model might look like this:

{
  "id": 123,
  "name": "Example Product",
  "description": "A great item.",
  "price": 19.99
}

Consistency in your data models makes your API predictable and easier to use.

RESTful APIs at the Edge

RESTful API design is particularly well-suited for edge computing environments like Cloudflare Workers:

Statelessness: Edge functions are often short-lived and don't maintain state, aligning perfectly with REST's stateless principle.
Caching: GET requests are easily cacheable by CDNs, which is a core benefit of edge computing for reducing latency.
Distributed Nature: REST's clear separation of concerns and uniform interface makes it easier to distribute logic across many edge locations.

API Design Check

You're building an API for a blog. You need to retrieve a list of all blog posts. Which of the following API endpoint designs and HTTP methods is the most RESTful?

Recap: RESTful API Design

Great job! You've learned the fundamentals of designing RESTful APIs:

APIs use resources (nouns) and HTTP methods (verbs) for communication.
Common methods are GET (retrieve), POST (create), PUT/PATCH (update), and DELETE (remove).
Endpoint paths should be clear, using plural nouns and avoiding verbs.
JSON is the standard format for data payloads.
REST's principles make it an excellent choice for edge computing due to statelessness and cacheability.

Next, we'll dive into input validation and security for your edge APIs!

よくある質問

「RESTful APIの設計」レッスンは無料ですか？

はい。「RESTful APIの設計」の完全なテキストはこのウェブで無料で読めます。インタラクティブに演習し（組み込みコードエディタと24時間対応のAIチューター）、Edge Computing with Cloudflare Workers & Denoコースの残りをアンロックするには、CoddyKit PROにアップグレードしてください。 Edge Computing with Cloudflare Workers & Denoコースには全3レッスンが含まれています。

「RESTful APIの設計」で何を学びますか？

エッジデプロイに適したRESTful APIのエンドポイント、メソッド、データモデルを計画・構成しますブラウザで直接実行するハンズオンコードでEdge Computing with Cloudflare Workers & Denoを演習し、24時間対応のAIチューターがレッスンを進める中での質問に答えます。

Edge Computing with Cloudflare Workers & Denoを始めるのに経験は必要ですか？

事前経験は必要ありません。CoddyKitのEdge Computing with Cloudflare Workers & Denoは初級者から上級者向けに構成されているため、ここから始めるか最初から始めて、自分のペースで進むことができます。これはレッスン1/3です。

「RESTful APIの設計」レッスンにはどのくらい時間がかかりますか？

ほとんどのCoddyKitレッスンは約5～10分かかります。各レッスンはコンパクトでインタラクティブなので、着実に進歩し、ウェブとアプリ全体で正確に前回の場所から再開できます。

このEdge Computing with Cloudflare Workers & Denoレッスンでコードを書いて実行できますか？

はい。すべてのEdge Computing with Cloudflare Workers & Denoレッスンに組み込みコードエディタが含まれているため、ブラウザでリアルコードを書いて実行し、即座のAIフィードバックを取得できます。ローカル設定は不要です。

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