feat: download redemption codes as file (#12)

web/src/helpers/utils.js

@@ -143,4 +143,13 @@ export function timestamp2string(timestamp) {
     ':' +
     second
   );
+}
+
+export function downloadTextAsFile(text, filename) {
+  let blob = new Blob([text], { type: 'text/plain;charset=utf-8' });
+  let url = URL.createObjectURL(blob);
+  let a = document.createElement('a');
+  a.href = url;
+  a.download = filename;
+  a.click();
 }