Baseline Widely available
Note: This feature is available in Web Workers, except for Service Workers.
The XMLHttpRequestUpload
interface represents the upload process for a specific XMLHttpRequest
. It is an opaque object that represents the underlying, browser-dependent, upload process. It is an XMLHttpRequestEventTarget
and can be obtained by calling XMLHttpRequest.upload
.
This interface has no specific property, but inherits the properties of XMLHttpRequestEventTarget
and of EventTarget
.
This interface has no specific method, but inherits the methods of XMLHttpRequestEventTarget
and of EventTarget
.
abort
Fired when a request has been aborted, for example because the program called XMLHttpRequest.abort()
. Also available via the onabort
event handler property.
error
Fired when the request encountered an error. Also available via the onerror
event handler property.
load
Fired when a request transaction completes successfully. Also available via the onload
event handler property.
loadend
Fired when a request has completed, whether successfully (after load
) or unsuccessfully (after abort
or error
). Also available via the onloadend
event handler property.
loadstart
Fired when a request has started to load data. Also available via the onloadstart
event handler property.
progress
Fired periodically when a request receives more data. Also available via the onprogress
event handler property.
timeout
Fired when progress is terminated due to preset time expiring. Also available via the ontimeout
event handler property.
This allows you to upload a file to a server; it displays a progress bar while the upload is happening as well as a message with the progress and the results, success or failure. An abort button allows to stop an upload.
HTML<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width" />
<title>XMLHttpRequestUpload test</title>
<link rel="stylesheet" href="xhrupload_test.css" />
<script src="xhrupload_test.js"></script>
</head>
<body>
<main>
<h1>Upload a file</h1>
<p>
<label for="file">File to upload</label><input type="file" id="file" />
</p>
<p>
<progress></progress>
</p>
<p>
<output></output>
</p>
<p>
<button disabled id="abort">Abort</button>
</p>
</main>
</body>
</html>
CSS
body {
background-color: lightblue;
}
main {
margin: 50px auto;
text-align: center;
}
#file {
display: none;
}
label[for="file"] {
background-color: lightgrey;
padding: 10px 10px;
}
progress {
display: none;
}
progress.visible {
display: inline;
}
JavaScript
addEventListener("DOMContentLoaded", () => {
const fileInput = document.getElementById("file");
const progressBar = document.querySelector("progress");
const log = document.querySelector("output");
const abortButton = document.getElementById("abort");
fileInput.addEventListener("change", () => {
const xhr = new XMLHttpRequest();
xhr.timeout = 2000; // 2 seconds
// Link abort button
abortButton.addEventListener(
"click",
() => {
xhr.abort();
},
{ once: true },
);
// When the upload starts, we display the progress bar
xhr.upload.addEventListener("loadstart", (event) => {
progressBar.classList.add("visible");
progressBar.value = 0;
progressBar.max = event.total;
log.textContent = "Uploading (0%)â¦";
abortButton.disabled = false;
});
// Each time a progress event is received, we update the bar
xhr.upload.addEventListener("progress", (event) => {
progressBar.value = event.loaded;
log.textContent = `Uploading (${(
(event.loaded / event.total) *
100
).toFixed(2)}%)â¦`;
});
// When the upload is finished, we hide the progress bar.
xhr.upload.addEventListener("loadend", (event) => {
progressBar.classList.remove("visible");
if (event.loaded !== 0) {
log.textContent = "Upload finished.";
}
abortButton.disabled = true;
});
// In case of an error, an abort, or a timeout, we hide the progress bar
// Note that these events can be listened to on the xhr object too
function errorAction(event) {
progressBar.classList.remove("visible");
log.textContent = `Upload failed: ${event.type}`;
}
xhr.upload.addEventListener("error", errorAction);
xhr.upload.addEventListener("abort", errorAction);
xhr.upload.addEventListener("timeout", errorAction);
// Build the payload
const fileData = new FormData();
fileData.append("file", fileInput.files[0]);
// Theoretically, event listeners could be set after the open() call
// but browsers are buggy here
xhr.open("POST", "upload_test.php", true);
// Note that the event listener must be set before sending (as it is a preflighted request)
xhr.send(fileData);
});
});
Specifications Browser compatibility See also
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4