When double-clicking on a file, the behavior is:

First click: open the viewer
Second click: close the viewer

But the second click does not correctly close the Viewer, as the method used to cancel the requests does not work.

This PR use modern API to cancel the requests. The requests are now correctly aborted, and the `openFile` method exit because the request call throws an exception.

Fix #893

https://axios-http.com/docs/cancellation
https://developer.mozilla.org/en-US/docs/Web/API/AbortController

Signed-off-by: Louis Chemineau <louis@chmn.me>

Author: artonge

js/viewer-main.js

@@ -82,6 +82,7 @@ object-assign
  *
  * @author Marco Ambrosini <marcoambrosini@pm.me>
  * @author John Molakvoæ <skjnldsv@protonmail.com>
+ * @author Louis Chemineau <louis@chmn.me>
  *
  * @license AGPL-3.0-or-later
  *

js/viewer-main.js.LICENSE.txt

@@ -3,6 +3,7 @@
  *
  * @author Marco Ambrosini <marcoambrosini@pm.me>
  * @author John Molakvoæ <skjnldsv@protonmail.com>
+ * @author Louis Chemineau <louis@chmn.me>
  *
  * @license AGPL-3.0-or-later
  *
@@ -21,20 +22,14 @@
  *
  */
 
-import axios from '@nextcloud/axios'
-
 /**
  * Creates a cancelable axios 'request object'.
  *
  * @param {Function} request the axios promise request
  * @return {object}
  */
 const CancelableRequest = function(request) {
-	/**
-	 * Generate an axios cancel token
-	 */
-	const CancelToken = axios.CancelToken
-	const source = CancelToken.source()
+	const controller = new AbortController()
 
 	/**
 	 * Execute the request
@@ -45,12 +40,12 @@ const CancelableRequest = function(request) {
 	const fetch = async function(url, options) {
 		return request(
 			url,
-			Object.assign({ cancelToken: source.token }, { options })
+			{ ...options, signal: controller.signal }
 		)
 	}
 	return {
 		request: fetch,
-		cancel: source.cancel,
+		cancel: () => controller.abort(),
 	}
 }