fix #2321 (#2322)

When Converse runs inside a browser extension, enable browser sync and local storage for persistent storage

CHANGES.md

@@ -40,6 +40,7 @@ Soon we'll deprecate the latter, so prepare now.
 - #2304: Custom emojis (stickers) images not shown 
 - #2307: BootstrapModal is not accessible to plugins
 - #2308: Allow getHats method to be overriden in the `overrides` object in plugins.
+- #2321: When Converse runs inside a browser extension, enable browser sync and local storage for persistent storage
 - The `trusted` configuration setting has been removed in favor of two new settings:
     [allow_user_trust_override](https://conversejs.org/docs/html/configuration.html#allow-user-trust-override)
     [clear_cache_on_logout](https://conversejs.org/docs/html/configuration.html#clear-cache-on-logout)

docs/source/configuration.rst

@@ -1587,7 +1587,7 @@ persistent_store
 ----------------
 
 * Default: ``localStorage``
-* Valid options: ``localStorage``, ``IndexedDB``, ``sessionStorage``
+* Valid options: ``localStorage``, ``IndexedDB``, ``sessionStorage``, ``BrowserExtLocal``, ``BrowserExtSync``
 
 Determines which store is used for storing persistent data.
 
@@ -1598,6 +1598,17 @@ IndexedDB is not subjected to the same space constraints as localStorage and is
 also a requirement for progressive web apps which don't need persistent a
 internet connectivity to be functional.
 
+From version 7.0.0 onwards, Converse supports storing data in
+`Browser Extension storage <https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/storage#Example_extensions>`_.
+
+When Converse is running inside a web browser extension, it can now take advantage of storage optimized to meet the specific storage needs of extensions.
+
+BrowserExtSync represents the sync storage area. 
+Items in sync storage are synced by the browser and are available across all instances of that browser that the user is logged into, across different devices.
+
+BrowserExtLocal represents the local storage area. 
+Items in local storage are local to the machine the extension was installed on
+
 
 push_app_servers
 ----------------

package.json

@@ -96,6 +96,7 @@
     "lerna": "^3.22.1",
     "lit-element": "^2.3.1",
     "lit-html": "^1.2.1",
+    "localforage-webextensionstorage-driver": "^2.0.0",
     "lodash-template-webpack-loader": "jcbrand/lodash-template-webpack-loader",
     "mini-css-extract-plugin": "^0.9.0",
     "minimist": "^1.2.3",

src/headless/converse-core.js

@@ -10,6 +10,8 @@ import advancedFormat from 'dayjs/plugin/advancedFormat';
 import dayjs from 'dayjs';
 import log from '@converse/headless/log';
 import pluggable from 'pluggable.js/src/pluggable';
+import syncDriver from 'localforage-webextensionstorage-driver/sync';
+import localDriver from 'localforage-webextensionstorage-driver/local';
 import sizzle from 'sizzle';
 import stanza_utils from "@converse/headless/utils/stanza";
 import u from '@converse/headless/utils/core';
@@ -976,7 +978,17 @@ async function initSessionStorage () {
 function initPersistentStorage () {
     if (api.settings.get('persistent_store') === 'sessionStorage') {
         return;
+    } else if (_converse.api.settings.get("persistent_store") === 'BrowserExtLocal') {
+        Storage.localForage.defineDriver(localDriver).then(() => Storage.localForage.setDriver('webExtensionLocalStorage'));
+        _converse.storage['persistent'] = Storage.localForage;
+        return;
+
+    } else if (_converse.api.settings.get("persistent_store") === 'BrowserExtSync') {
+        Storage.localForage.defineDriver(syncDriver).then(() => Storage.localForage.setDriver('webExtensionSyncStorage'));
+        _converse.storage['persistent'] = Storage.localForage;
+        return;
     }
+
     const config = {
         'name': _converse.isTestEnv() ? 'converse-test-persistent' : 'converse-persistent',
         'storeName': _converse.bare_jid