feat(core): offer clipboard fallback for non-secure environments

Signed-off-by: skjnldsv <skjnldsv@protonmail.com>

core/src/init.js

@@ -14,6 +14,7 @@ import { setUp as setUpContactsMenu } from './components/ContactsMenu.js'
 import { setUp as setUpMainMenu } from './components/MainMenu.js'
 import { setUp as setUpUserMenu } from './components/UserMenu.js'
 import { interceptRequests } from './utils/xhr-request.js'
+import { initFallbackClipboardAPI } from './utils/ClipboardFallback.ts'
 
 // keep in sync with core/css/variables.scss
 const breakpointMobileWidth = 1024
@@ -58,6 +59,7 @@ moment.locale(locale)
  */
 export const initCore = () => {
 	interceptRequests()
+	initFallbackClipboardAPI()
 
 	$(window).on('unload.main', () => { OC._unloadCalled = true })
 	$(window).on('beforeunload.main', () => {

core/src/utils/ClipboardFallback.ts

@@ -0,0 +1,47 @@
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+import { t } from '@nextcloud/l10n'
+
+/**
+ *
+ * @param text
+ */
+function unsecuredCopyToClipboard(text) {
+	const textArea = document.createElement('textarea')
+	const textAreaContent = document.createTextNode(text)
+	textArea.appendChild(textAreaContent)
+	document.body.appendChild(textArea)
+
+	textArea.focus({ preventScroll: true })
+	textArea.select()
+
+	try {
+		// This is a fallback for browsers that do not support the Clipboard API
+		// execCommand is deprecated, but it is the only way to copy text to the clipboard in some browsers
+		document.execCommand('copy')
+	} catch (err) {
+		window.prompt(t('core', 'Clipboard not available, please copy manually'), text)
+		console.error('[ERROR] core:  files Unable to copy to clipboard', err)
+	}
+
+	document.body.removeChild(textArea)
+}
+
+/**
+ *
+ */
+function initFallbackClipboardAPI() {
+	if (!window.navigator?.clipboard?.writeText) {
+		console.info('[INFO] core: Clipboard API not available, using fallback')
+		Object.defineProperty(window.navigator, 'clipboard', {
+			value: {
+				writeText: unsecuredCopyToClipboard,
+			},
+			writable: false,
+		})
+	}
+}
+
+export { initFallbackClipboardAPI }