popup.js

// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

document.addEventListener('DOMContentLoaded', function(){
  const ls = document.querySelector('#listen-domain')
  const sy = document.querySelector('#sync-url')
  const syncBtn = document.querySelector('#save-btn')

  // backfill config
  chrome.storage.sync.get(
      ['listenDomain', 'syncURL'],
      ({ listenDomain = [], syncURL = '' }) => {
        ls.value = listenDomain.join('\n')
        sy.value = syncURL
      }
  )

  // set new config
  syncBtn.onclick = () => {
    const listenDomain = ls.value.trim().split(/\n/)
    const syncURL = sy.value.trim()
    if (listenDomain && syncURL) {
      chrome.storage.sync.set({ listenDomain, syncURL })
    }
  }

})