Request/Response

Request

The Request is part of URL_ADDRESS is part of the Fetch API. It represents an HTTP request and provides information about the request.

In fetch handler, you can get the request object by request parameter of incoming request.

export default {
  async fetch(request, env, ctx) {
    return new Response(`Hello, ${request.url}`);
  }
}

The incoming requests is immutable. You can create a new request object by passing the URL to the Request constructor to fetch remote resources.

export default {
  async fetch(request, env, ctx) {
    const url = new URL(request.url);
    // add query parameter
    url.searchParams.set('name', 'John');
    const response = await fetch(url.toString(), request);
    return new Response(response.body, response);
  }
}

Constructor

let request = new Request(input, options);

// input: string | Request
// options: RequestInit
let request = new Request('URL_ADDRESS', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    name: 'John'
  }),
  redirect: 'follow'
});

options.redirect is used to specify how to handle redirects. It can be one of the following values: follow (default), error, manual.

Properties

• request.url: The URL of the request, string readonly.
• request.method: The HTTP method of the request, e.g. GET, POST, PUT, DELETE, etc.
• request.headers: A Headers object containing the request headers.
• request.body: A ReadableStream object containing the request body.
• request.bodyUsed: A boolean indicating whether the request body has been used.
• request.redirect: The redirect mode of the request, one of follow, error, manual.

Methods

• request.clone(): Returns a new Request object with the same properties as the original request.
• request.arrayBuffer(): Returns a Promise that resolves to a ArrayBuffer containing the request body.
• request.formData(): Returns a Promise that resolves to a FormData object containing the request body.
• request.json(): Returns a Promise that resolves to a JSON object containing the request body.
• request.text(): Returns a Promise that resolves to a string containing the request body.

Response

The Response is a part of Fetch API. It represents an HTTP response and provides information about the response.

Constructor

let response = new Response(body, options);

// body: string | Blob | BufferSource | FormData | URLSearchParams | ReadableStream | null
// options: ResponseInit
let response = new Response('Hello, World!', {
  status: 200,
  statusText: 'OK',
  headers: {
    'Content-Type': 'text/plain'
  }
});

The body parameter can be null or a ReadableStream object, a BufferSource object, a FormData object, a URLSearchParams object and string.

Properties

• response.status: The HTTP status code of the response, number readonly.
• response.statusText: The HTTP status text of the response, string readonly.
• response.headers: A Headers object containing the response headers.
• response.url: The URL of the response, string readonly.
• response.body: A ReadableStream object containing the response body.
• response.bodyUsed: A boolean indicating whether the response body has been used.
• response.ok: A boolean indicating whether the response is successful (status in the range 200-299).
• response.redirected: A boolean indicating whether the response was redirected.

Static methods

• Response.error(): Returns a new Response object with the specified status code and status text.
• Response.redirect(url, status): Returns a new Response object with the specified status code and status text and a Location header set to the specified URL.
• Response.clone(response): Returns a new Response object with the same properties as the specified response.

Methods

• response.arrayBuffer(): Returns a Promise that resolves to a ArrayBuffer containing the response body.
• response.formData(): Returns a Promise that resolves to a FormData object containing the response body.
• response.json(): Returns a Promise that resolves to a JSON object containing the response body.
• response.text(): Returns a Promise that resolves to a string containing the response body.

About Cotent-Length

The Content-Length header is auto calculated by the Response object. But ReadableStream object can not be calculated. The Content-Length will be set Transfer-Encoding: chunked.