Persist 4chan native extension settings

readme.md

View the "raw" version of the script source to install.

persistence.user.js

// ==UserScript==
// @name        4chan settings persistence
// @namespace   queue
// @author      queue
// @description Save 4chan JS settings to GM_preferences, which persist through cookie deletion.
// @include     https://boards.4chan.org/*
// @include     http://boards.4chan.org/*
// @version     1
// @run-at      document-start
// @grant       GM_getValue
// @grant       GM_setValue
// @grant       GM_deleteValue
// @grant       GM_listValues
// ==/UserScript==

//console.log('loading')

GM_listValues().forEach(function (k) {
  //console.log(k)
  localStorage.setItem(k, GM_getValue(k))
})

window.addEventListener('beforeunload', function () {
  //console.log('saving...')

  // clean up deleted
  GM_listValues().forEach(function (k) {
    //console.log(k)
    if (!(localStorage.getItem(k))) {
      GM_deleteValue(k)
    }
  })
  Object.keys(localStorage)
    .filter(RegExp.prototype.test.bind(/^4chan-/)) // only native extension
    .forEach(function (k) {
      //console.log(k)
      GM_setValue(k, localStorage.getItem(k))
    })
})