Issue 2040 - Replaced localStorage with chrome.storage.local

lib/prefs.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2015 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 const keyPrefix = "pref:";
 
-let prefs = Object.create(null);
-let listeners = [];
+let defaults = Object.create(null);
+let overrides = Object.create(null);
+
+defaults.enabled = true;
+defaults.currentVersion = "";
+defaults.data_directory = "";
+defaults.patternsbackups = 5;
+defaults.patternsbackupinterval = 24;
+defaults.savestats = false;
+defaults.privateBrowsing = false;
+defaults.subscriptions_fallbackerrors = 5;
+defaults.subscriptions_fallbackurl = "https://adblockplus.org/getSubscription?version=%VERSION%&url=%SUBSCRIPTION%&downloadURL=%URL%&error=%ERROR%&channelStatus=%CHANNELSTATUS%&responseStatus=%RESPONSESTATUS%";
+defaults.subscriptions_autoupdate = true;
+defaults.subscriptions_exceptionsurl = "https://easylist-downloads.adblockplus.org/exceptionrules.txt";
+defaults.subscriptions_antiadblockurl = "https://easylist-downloads.adblockplus.org/antiadblockfilters.txt";
+defaults.documentation_link = "https://adblockplus.org/redirect?link=%LINK%&lang=%LANG%";
+defaults.notificationdata = {};
+defaults.notificationurl = "https://notification.adblockplus.org/notification.json";
+defaults.stats_total = {};
+defaults.show_statsinicon = true;
+defaults.show_statsinpopup = true;
+defaults.shouldShowBlockElementMenu = true;
+defaults.hidePlaceholders = true;
 
 let Prefs = exports.Prefs = {
-  addListener: function(listener)
-  {
-    if (listeners.indexOf(listener) < 0)
-      listeners.push(listener);
-  },
-
-  removeListener: function(listener)
-  {
-    let index = listeners.indexOf(listener);
-    if (index >= 0)
-      listeners.splice(index, 1);
-  }
+  onChanged: new ext._EventTarget(),
+  onLoaded: new ext._EventTarget()
 };
 
 function keyToPref(key)
 {
   if (key.indexOf(keyPrefix) != 0)
     return null;
 
   return key.substr(keyPrefix.length);
 }
 
 function prefToKey(pref)
 {
   return keyPrefix + pref;
 }
 
-function addPreference(pref, defaultValue)
+function addPreference(pref)
 {
-  prefs[pref] = undefined;
-
   Object.defineProperty(Prefs, pref, {
     get: function()
     {
-      let value = prefs[pref];
-
-      if (typeof value != "undefined")
-        return value;
-
-      return defaultValue;
+      return (pref in overrides ? overrides : defaults)[pref];
     },
     set: function(value)
     {
+      let defaultValue = defaults[pref];
+
       if (typeof value != typeof defaultValue)
         throw new Error("Attempt to change preference type");
 
       if (value == defaultValue)
       {
-        prefs[pref] = undefined;
+        delete overrides[pref];
         ext.storage.remove(prefToKey(pref));
       }
       else
       {
-        prefs[pref] = value;
+        overrides[pref] = value;
         ext.storage.set(prefToKey(pref), value);
       }
     },
     enumerable: true
   });
 }
 
-function setPreference(pref, value)
+function init()
 {
-  prefs[pref] = value;
+  let prefs = Object.keys(defaults);
+  prefs.forEach(addPreference);
 
-  for (let listener of listeners)
-    listener(pref);
+  // Migrate preferences for users updating from old versions.
+  // TODO: Remove the migration code after a few releases.
+  ext.storage.migratePrefs({
+    map: function(key, value)
+    {
+      if (key in defaults)
+      {
+        if (key != "currentVersion")
+        {
+          try
+          {
+            value = JSON.parse(value);
+          }
+          catch (e)
+          {
+            return null;
+          }
+        }
+
+        return {key: prefToKey(key), value: value};
+      }
+
+      return null;
+    },
+
+    done: function()
+    {
+      ext.storage.get(prefs.map(prefToKey), function(items)
+      {
+        for (let key in items)
+          overrides[keyToPref(key)] = items[key];
+
+        ext.storage.onChanged.addListener(function(changes)
+        {
+          for (let key in changes)
+          {
+            let pref = keyToPref(key);
+            if (pref && pref in defaults)
+            {
+              let change = changes[key];
+              if ("newValue" in change && change.newValue != defaults[pref])
+                overrides[pref] = change.newValue;
+              else
+                delete overrides[pref];
+
+              Prefs.onChanged._dispatch(pref);
+            }
+          }
+        });
+
+        Prefs.onLoaded._dispatch();
+      });
+    }
+  });
 }
 
-addPreference("enabled", true);
-addPreference("data_directory", "");
-addPreference("patternsbackups", 5);
-addPreference("patternsbackupinterval", 24);
-addPreference("savestats", false);
-addPreference("privateBrowsing", false);
-addPreference("subscriptions_fallbackerrors", 5);
-addPreference("subscriptions_fallbackurl", "https://adblockplus.org/getSubscription?version=%VERSION%&url=%SUBSCRIPTION%&downloadURL=%URL%&error=%ERROR%&channelStatus=%CHANNELSTATUS%&responseStatus=%RESPONSESTATUS%");
-addPreference("subscriptions_autoupdate", true);
-addPreference("subscriptions_exceptionsurl", "https://easylist-downloads.adblockplus.org/exceptionrules.txt");
-addPreference("subscriptions_antiadblockurl", "https://easylist-downloads.adblockplus.org/antiadblockfilters.txt");
-addPreference("documentation_link", "https://adblockplus.org/redirect?link=%LINK%&lang=%LANG%");
-addPreference("notificationdata", {});
-addPreference("notificationurl", "https://notification.adblockplus.org/notification.json");
-addPreference("stats_total", {});
-addPreference("show_statsinicon", true);
-addPreference("show_statsinpopup", true);
-addPreference("shouldShowBlockElementMenu", true);
-addPreference("hidePlaceholders", true);
-
-// Migrate preferences for users updating from old versions.
-// TODO: Remove the migration code after a few releases.
-ext.storage.migratePrefs(function(key, value)
-{
-  if (key in prefs)
-  {
-    key = prefToKey(key);
-    try
-    {
-      value = JSON.parse(value);
-    }
-    catch (e)
-    {
-      return null;
-    }
-  }
-  else if (key != "currentVersion")
-  {
-    return null;
-  }
-
-  return {key: key, value: value};
-});
-
-ext.storage.get(Object.keys(prefs).map(prefToKey), function(items)
-{
-  for (let key in items)
-    setPreference(keyToPref(key), items[key]);
-
-  ext.storage.onChanged.addListener(function(changes)
-  {
-    for (let key in changes)
-    {
-      let pref = keyToPref(key);
-      if (pref && pref in prefs)
-        setPreference(pref, changes[key].newValue);
-    }
-  });
-});
+init();