Response: redirected property
The read-only redirected
property of the Response
interface indicates whether or not the response is the result of a request you made which was redirected.
Note: Relying on redirected to filter out redirects makes it easy for a forged redirect to prevent your content from working as expected.
Instead, you should do the filtering when you call fetch()
.
See the example Disallowing redirects, which shows this being done.
Value
A boolean value which is true
if the response indicates that your request was redirected.
Examples
Detecting redirects
Checking to see if the response comes from a redirected request is as simple as checking this flag on the Response
object.
In the code below, a textual message is inserted into an element when a redirect occurred during the fetch operation.
Note, however, that this isn't as safe as outright rejecting redirects if they're unexpected, as described under Disallowing redirects below.
The url
property returns the final URL after redirects.
js
fetch("awesome-picture.jpg")
.then((response) => {
const elem = document.getElementById("warning-message-box");
elem.textContent = response.redirected ? "Unexpected redirect" : "";
// final url obtained after redirects
console.log(response.url);
return response.blob();
})
.then((imageBlob) => {
const imgObjectURL = URL.createObjectURL(imageBlob);
document.getElementById("img-element-id").src = imgObjectURL;
});
Disallowing redirects
Because using redirected to manually filter out redirects can allow forgery of redirects, you should instead set the redirect mode to "error"
in the init
parameter when calling fetch()
, like this:
js
fetch("awesome-picture.jpg", { redirect: "error" })
.then((response) => response.blob())
.then((imageBlob) => {
const imgObjectURL = URL.createObjectURL(imageBlob);
document.getElementById("img-element-id").src = imgObjectURL;
});
Specifications
Specification |
---|
Fetch Standard # ref-for-dom-response-redirected① |
Browser compatibility
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