feat: add fallback for useCopyToClipboard (#2343)

Co-authored-by: Dominik Pschenitschni <mail@celement.de>
Reviewed-on: https://kolaente.dev/vikunja/frontend/pulls/2343
Reviewed-by: konrad <k@knt.li>
Co-authored-by: Dominik Pschenitschni <dpschen@noreply.kolaente.de>
Co-committed-by: Dominik Pschenitschni <dpschen@noreply.kolaente.de>

src/composables/useCopyToClipboard.ts

@@ -4,10 +4,41 @@ import {useI18n} from 'vue-i18n'
 export function useCopyToClipboard() {
 	const {t} = useI18n({useScope: 'global'})
 	
+	function fallbackCopyTextToClipboard(text: string) {
+		const textArea = document.createElement('textarea')
+		textArea.value = text
+		
+		// Avoid scrolling to bottom
+		textArea.style.top = '0'
+		textArea.style.left = '0'
+		textArea.style.position = 'fixed'
+	
+		document.body.appendChild(textArea)
+		textArea.focus()
+		textArea.select()
+	
+		try {
+			// NOTE: the execCommand is deprecated but as of 2022_09
+			// widely supported and works without https
+			const successful = document.execCommand('copy')
+			if (!successful) {
+				throw new Error()
+			}
+		} catch (err) {
+			error(t('misc.copyError'))
+		}
+	
+		document.body.removeChild(textArea)
+	}
+	
 	return async (text: string) => {
+		if (!navigator.clipboard) {
+			fallbackCopyTextToClipboard(text)
+			return
+		}
 		try {
 			await navigator.clipboard.writeText(text)
-		} catch {
+		} catch(e) {
 			error(t('misc.copyError'))
 		}
 	}