Merge branch 'XMLHttpRequestUpload' of github.com:teoli2003/content i…

…nto XMLHttpRequestUpload

files/en-us/web/api/xmlhttprequestupload/index.md

@@ -7,7 +7,7 @@ browser-compat: api.XMLHttpRequestUpload
 
 {{DefaultAPISidebar("XMLHttpRequest")}}
 
-The **`XMLHttpRequestUpload`** interface represents the upload process, allowing to listen for events associated with a specific {{domxref("XMLHttpRequest")}}. It is an _opaque_ object that represents the underlying, browser-dependant, upload process. It is {{domxref("XMLHttpRequestEventTarget")}} and is can be obtained by calling {{domxref("XMLHttpRequest.upload")}}.
+The **`XMLHttpRequestUpload`** interface represents the upload process, allowing it to listen for events associated with a specific {{domxref("XMLHttpRequest")}}. It is an _opaque_ object that represents the underlying, browser-dependant, upload process. It is {{domxref("XMLHttpRequestEventTarget")}} and is can be obtained by calling {{domxref("XMLHttpRequest.upload")}}.
 
 {{AvailableInWorkers("notservice")}}
 

files/en-us/web/api/xmlhttprequestupload/readystatechange_event/index.md

@@ -0,0 +1,62 @@
+---
+title: 'XMLHttpRequestUpload: readystatechange event'
+slug: Web/API/XMLHttpRequestUpload/readystatechange_event
+page-type: web-api-event
+browser-compat: api.XMLHttpRequestUpload.readystatechange_event
+---
+
+{{APIRef}}
+
+The `readystatechange` event is fired whenever the {{domxref("XMLHttpRequest.readyState", "readyState")}} property of the {{domxref("XMLHttpRequest")}} changes.
+
+> **Warning:** This should not be used with synchronous requests and must
+> not be used from native code.
+
+## Syntax
+
+Use the event name in methods like {{domxref("EventTarget.addEventListener", "addEventListener()")}}, or set an event handler property.
+
+```js
+addEventListener('readystatechange', (event) => { })
+
+onreadystatechange = (event) => { }
+```
+
+## Event type
+
+A generic {{DOMxRef("Event")}} with no added properties.
+
+## Examples
+
+```js
+const xhr = new XMLHttpRequest();
+const method = "GET";
+const url = "https://developer.mozilla.org/";
+
+xhr.open(method, url, true);
+xhr.onreadystatechange = () => {
+  // In local files, status is 0 upon success in Mozilla Firefox
+  if (xhr.readyState === XMLHttpRequest.DONE) {
+    const status = xhr.status;
+    if (status === 0 || (status >= 200 && status < 400)) {
+      // The request has been completed successfully
+      console.log(xhr.responseText);
+    } else {
+      // Oh no! There has been an error with the request!
+    }
+  }
+};
+xhr.send();
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- {{domxref("XMLHttpRequestUpload")}}