Response
Baseline
Widely available
*
This feature is well established and works across many devices and browser versions. It’s been available across browsers since 2017年3月.
* Some parts of this feature may have varying levels of support.
Fetch API 的 Response 介面代表了一個請求會返回的回應。
你可以用 Response.Response() 建構子創建一個新的 Response物件。但實務上碰到 Response 物件的時機，比較常出現在進行了一個 API 操作後，得到返回的 Response 物件。舉例而言，使用 service worker Fetchevent.respondWith 或是使用單純的GlobalFetch.fetch()。
建構子
Response()-
創建一個新的
Response物件。
屬性
Response.headersRead only-
包含與此 response 相關的
Headers物件。 Response.okRead only-
無論此 response 是不是成功 ( 狀態碼 200-299 ) 都會包含一個 boolean 狀態。
Response.redirectedRead only-
指出此 response 是不是個重新導向的結果，如果是的話，代表此 URL 具有一個以上的入口。
Response.statusRead only-
包含此 response 的狀態碼(例如：成功時為
200)。 Response.statusTextRead only-
包含狀態碼所對應的狀態文字 (例如：
OK對應200)。 Response.typeRead only-
包含此 response 的類型 (例如：
basic,cors)。 Response.urlRead only-
包含此 response 的 URL。
Response.useFinalURL-
包含一個 boolean 狀態，指出此 URL 是否為此 response 的最後一步。
Response 實做了Body, 所以它另有以下可用的屬性：
Body.bodyRead only-
A simple getter used to expose a
ReadableStreamof the body contents. Body.bodyUsedRead only-
Stores a
Booleanthat declares whether the body has been used in a response yet.
方法
Response.clone()-
建立一份
Response的複製物件。 Response.error()-
Returns a new
Responseobject associated with a network error. Response.redirect()-
Creates a new response with a different URL.
Response implements Body, so it also has the following methods available to it:
Body.arrayBuffer()-
Takes a
Responsestream and reads it to completion. It returns a promise that resolves with anArrayBuffer. Body.blob()-
Takes a
Responsestream and reads it to completion. It returns a promise that resolves with aBlob. Body.formData()-
Takes a
Responsestream and reads it to completion. It returns a promise that resolves with aFormDataobject. Body.json()-
Takes a
Responsestream and reads it to completion. It returns a promise that resolves with the result of parsing the body text asJSON. Body.text()-
Takes a
Responsestream and reads it to completion. It returns a promise that resolves with aUSVString(text).
範例
在基本 fetch 範例 (run example live) 中，我們使用 fetch() 呼叫來得到圖片，並使用 <img> tag 顯示。 這裡的fetch() 呼叫返回了一個 promise，它使用與資源 fetch 操作有關的 Response 進行解析。你可能有發現，由於我們要求的是一張圖片，所以需要用 Body.blob (Response 時做了 body) 讓 response 有正確的 MIME 類型。
const image = document.querySelector(".my-image");
fetch("flowers.jpg")
.then(function (response) {
return response.blob();
})
.then(function (blob) {
const objectURL = URL.createObjectURL(blob);
image.src = objectURL;
});
除此之外，你也能用 Response.Response() 建構子去建立自己的客製化 Response 物件：
const response = new Response();
規範
| Specification |
|---|
| Fetch # response-class |
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