feat: fetch access token from indexedDb

src/App.js

@@ -1,11 +1,13 @@
 import React, { Suspense, useEffect, useState } from "react";
+
 import { RestfulProvider } from "restful-react";
 import sdk from "matrix-js-sdk";
 
+import { MatrixClientContext } from "./contexts";
+import * as StorageManager from "./StorageManager";
 import AdminHome from "./AdminHome";
 import DelayedSpinner from "./DelayedSpinner";
 import Login from "./Login";
-import { MatrixClientContext } from "./contexts";
 
 import "./css/App.scss";
 
@@ -17,21 +19,24 @@ export default () => {
     useEffect(() => {
         Promise.resolve(getHsBaseUrl()).then(baseUrl => {
             let client;
-            const accessToken = localStorage.getItem("mx_access_token");
-            const userId = localStorage.getItem("mx_user_id");
-
-            if (accessToken && userId) {
-                client = sdk.createClient({
-                    baseUrl,
-                    accessToken,
-                    userId,
-                });
-                setupClient(client);
-            } else {
-                client = sdk.createClient({ baseUrl });
-                setMissingAccessToken(true);
-            }
-            setClient(client);
+            StorageManager.idbLoad("account", "mx_access_token").then(accessToken => {
+                if (!accessToken) {
+                    accessToken = localStorage.getItem("mx_access_token");
+                }
+                const userId = localStorage.getItem("mx_user_id");
+                if (accessToken && userId) {
+                    client = sdk.createClient({
+                        baseUrl,
+                        accessToken,
+                        userId,
+                    });
+                    setupClient(client);
+                } else {
+                    client = sdk.createClient({ baseUrl });
+                    setMissingAccessToken(true);
+                }
+                setClient(client);
+            });
         });
     }, []);
 

src/StorageManager.js

@@ -0,0 +1,91 @@
+/*
+Copyright 2019 New Vector Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// just *accessing* indexedDB throws an exception in firefox if disabled.
+let indexedDB;
+try {
+    indexedDB = window.indexedDB;
+} catch (e) {}
+
+let idb = null;
+
+async function idbInit() {
+    if (!indexedDB) {
+        throw new Error("IndexedDB not available");
+    }
+    idb = await new Promise((resolve, reject) => {
+        const request = indexedDB.open("matrix-react-sdk", 1);
+        request.onerror = reject;
+        request.onsuccess = event => {
+            resolve(request.result);
+        };
+        request.onupgradeneeded = event => {
+            const db = request.result;
+            db.createObjectStore("account");
+        };
+    });
+}
+
+export async function idbLoad(table, key) {
+    if (!idb) {
+        await idbInit();
+    }
+    return new Promise((resolve, reject) => {
+        const txn = idb.transaction([table], "readonly");
+        txn.onerror = reject;
+
+        const objectStore = txn.objectStore(table);
+        const request = objectStore.get(key);
+        request.onerror = reject;
+        request.onsuccess = event => {
+            resolve(request.result);
+        };
+    });
+}
+
+export async function idbSave(table: string, key: string | string[], data: any): Promise<void> {
+    if (!idb) {
+        await idbInit();
+    }
+    return new Promise((resolve, reject) => {
+        const txn = idb.transaction([table], "readwrite");
+        txn.onerror = reject;
+
+        const objectStore = txn.objectStore(table);
+        const request = objectStore.put(data, key);
+        request.onerror = reject;
+        request.onsuccess = event => {
+            resolve();
+        };
+    });
+}
+
+export async function idbDelete(table: string, key: string | string[]): Promise<void> {
+    if (!idb) {
+        await idbInit();
+    }
+    return new Promise((resolve, reject) => {
+        const txn = idb.transaction([table], "readwrite");
+        txn.onerror = reject;
+
+        const objectStore = txn.objectStore(table);
+        const request = objectStore.delete(key);
+        request.onerror = reject;
+        request.onsuccess = event => {
+            resolve();
+        };
+    });
+}