Edge Computing with Cloudflare Workers & Deno · Lección

Gestión de solicitudes HTTP

Escriba un Worker básico que intercepte y responda a solicitudes HTTP para demostrar su funcionalidad principal.

Gestión de solicitudes HTTP es una lección gratuita de Edge Computing with Cloudflare Workers & Deno en CoddyKit. Esta es la lección 2 de 4. Puedes leer la lección completa abajo gratuitamente — luego la practicas en el navegador con un editor de código integrado y un tutor de IA 24/7. Forma parte de la ruta de aprendizaje de Edge Computing with Cloudflare Workers & Deno, y tu progreso se sincroniza en la web y la app de CoddyKit. El curso de Edge Computing with Cloudflare Workers & Deno incluye 4 lecciones en total.

Partes de esta lección aún no han sido traducidas y se muestran en inglés.

Workers and Web Requests

Cloudflare Workers are powerful tools that sit at the edge of the internet. Think of them as highly efficient gatekeepers for your web traffic.

Their primary job is to intercept incoming HTTP requests, process them using your code, and then send back an appropriate HTTP response.

Understanding the Request

Every time a user's browser interacts with your Worker, it receives a Request object. This object is packed with all the details about the incoming request:

URL: The full web address the user tried to reach.
Method: The HTTP action, like GET (fetching data) or POST (sending data).
Headers: Extra information such as the browser type, cookies, and preferred language.
Body: Any data sent with the request, common with POST or PUT methods.

Catching the Fetch Event

Cloudflare Workers use an event listener to 'catch' incoming requests. The fetch event is triggered for every HTTP request that hits your Worker.

The standard entry point for a Worker is an exported object with an async fetch method. This method receives the request object as its first argument.

export default {
  async fetch(request, env, ctx) {
    // Your Worker logic goes here
    // The 'request' object holds all incoming request details
    return new Response("Hello from Worker!");
  }
}

Crafting a Simple Response

After your Worker processes a request, it needs to send back a Response object. This object contains the content and metadata that the user's browser will receive.

A basic Response can be created by simply passing a string of text to its constructor.

export default {
  async fetch(request, env, ctx) {
    const responseText = "Welcome to the edge!";
    return new Response(responseText);
  }
}

Your First 'Hello Worker!'

Let's combine what we've learned to create a simple Worker that says "Hello Cloudflare Worker!" to every incoming request.

This is the fundamental structure you'll use for almost all Cloudflare Workers.

export default {
  async fetch(request, env, ctx) {
    return new Response("Hello Cloudflare Worker!");
  }
}

Peeking at the Request URL

You can access various properties of the request object to get information about the incoming request. For example, request.url gives you the full URL that was requested.

This allows you to create dynamic responses based on the specific path or query parameters a user is trying to reach.

export default {
  async fetch(request, env, ctx) {
    const url = request.url;
    return new Response(`You requested: ${url}`);
  }
}

Responding to GET vs. POST

The request.method property tells you the HTTP method used (e.g., GET, POST, PUT, DELETE). You can use this to provide different logic for different types of requests.

For instance, a GET request might fetch data, while a POST request might submit data for creation.

export default {
  async fetch(request, env, ctx) {
    if (request.method === "GET") {
      return new Response("This is a GET request.");
    } else if (request.method === "POST") {
      return new Response("This is a POST request.", { status: 201 });
    }
    return new Response("Method not allowed.", { status: 405 });
  }
}

Custom Headers and Status

You can customize the Response object further by adding HTTP headers or changing the status code. This is done by passing an options object as the second argument to the Response constructor.

Headers: Provide metadata about the response (e.g., Content-Type: text/plain).
Status Code: Indicates the outcome of the request (e.g., 200 OK, 404 Not Found).

export default {
  async fetch(request, env, ctx) {
    return new Response("Custom response!", {
      status: 200,
      headers: {
        "Content-Type": "text/plain",
        "X-Worker-Info": "Processed at the Edge"
      }
    });
  }
}

Fetching from an Origin

Often, your Worker will act as a proxy. This means it fetches content from an 'origin server' (your actual website or API backend) and potentially modifies it before sending it to the user.

You can use the global fetch() function, passing it the original request object, to forward the request to another server.

export default {
  async fetch(request, env, ctx) {
    // Fetch the request from the origin server
    const response = await fetch(request);
    // You can modify the response here before returning it
    return response;
  }
}

Worker Response Check

You're building a Cloudflare Worker. Which of the following correctly sets the status code of a response to 404 Not Found?

Recap: Handling HTTP Requests

In this lesson, you learned the core of Cloudflare Workers: how they handle HTTP requests and send back responses.

Workers intercept fetch events.
The Request object contains all incoming request data.
You return a Response object to the user.
You can access request details like URL and method.
Responses can have custom status codes and headers.
Workers can act as proxies, fetching content from origin servers.

Next, you'll learn the steps to deploy your first Worker to Cloudflare's edge network so it can start serving users globally!

Preguntas frecuentes

¿La lección «Gestión de solicitudes HTTP» es gratis?

Sí — el texto completo de «Gestión de solicitudes HTTP» es gratis para leer aquí en la web. Para practicarla de forma interactiva (editor de código integrado y tutor de IA 24/7) y desbloquear el resto del curso de Edge Computing with Cloudflare Workers & Deno, actualiza a CoddyKit PRO. El curso de Edge Computing with Cloudflare Workers & Deno incluye 4 lecciones en total.

¿Qué aprenderé en «Gestión de solicitudes HTTP»?

Escriba un Worker básico que intercepte y responda a solicitudes HTTP para demostrar su funcionalidad principal. Practicas Edge Computing with Cloudflare Workers & Deno con código real que ejecutas directamente en el navegador, y un tutor de IA 24/7 responde tus preguntas mientras trabajas en la lección.

¿Necesito experiencia previa para empezar Edge Computing with Cloudflare Workers & Deno?

No se requiere experiencia previa. Edge Computing with Cloudflare Workers & Deno en CoddyKit está estructurado para principiantes hasta estudiantes avanzados, así que puedes empezar aquí o desde el inicio y avanzar a tu ritmo. Esta es la lección 2 de 4.

¿Cuánto tiempo toma la lección «Gestión de solicitudes HTTP»?

La mayoría de las lecciones de CoddyKit toman alrededor de 5–10 minutos. Cada una es compacta e interactiva, así que avanzas constantemente y retomas exactamente por donde dejaste en la web y la app.

¿Puedo escribir y ejecutar código en esta lección de Edge Computing with Cloudflare Workers & Deno?

Sí. Cada lección de Edge Computing with Cloudflare Workers & Deno incluye un editor de código integrado, así que escribes y ejecutas código real directamente en tu navegador y obtienes retroalimentación instantánea de IA — sin configuración local necesaria.

Todas las lecciones de este curso

Configuración del entorno de Workers
Gestión de solicitudes HTTP
Implementación de su primer Worker
Variables de entorno y secretos en Workers

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