add local and memory storage to web storage service

src/services/webStorage.service.ts

@@ -1,27 +1,60 @@
 import { StorageService } from 'jslib/abstractions/storage.service';
+import { ConstantsService } from 'jslib/services';
 
 export class WebStorageService implements StorageService {
+    private memoryStore = new Map<string, any>();
+    private memoryKeys = new Set(['key']);
+    private localStorageKeys = new Set(['appId', 'anonymousAppId', 'rememberedEmail',
+        ConstantsService.disableFaviconKey, ConstantsService.lockOptionKey, ConstantsService.localeKey,
+        ConstantsService.lockOptionKey]);
+
     get<T>(key: string): Promise<T> {
-        const json = window.sessionStorage.getItem(key);
+        if (this.memoryKeys.has(key)) {
-        if (json == null) {
+            if (this.memoryStore.has(key)) {
-            return Promise.resolve(null);
+                const obj = this.memoryStore.get(key);
+                return Promise.resolve(obj as T);
             }
+        } else {
+            let json: string = null;
+            if (this.localStorageKeys.has(key)) {
+                json = window.localStorage.getItem(key);
+            } else {
+                json = window.sessionStorage.getItem(key);
+            }
+            if (json != null) {
                 const obj = JSON.parse(json);
                 return Promise.resolve(obj as T);
             }
+        }
+        return Promise.resolve(null);
+    }
 
     save(key: string, obj: any): Promise<any> {
         if (obj == null) {
-            this.remove(key);
+            return this.remove(key);
-            return;
         }
+
+        if (this.memoryKeys.has(key)) {
+            this.memoryStore.set(key, obj);
+        } else {
             const json = JSON.stringify(obj);
+            if (this.localStorageKeys.has(key)) {
+                window.localStorage.setItem(key, json);
+            } else {
                 window.sessionStorage.setItem(key, json);
+            }
+        }
         return Promise.resolve();
     }
 
     remove(key: string): Promise<any> {
+        if (this.memoryKeys.has(key)) {
+            this.memoryStore.delete(key);
+        } else if (this.localStorageKeys.has(key)) {
+            window.localStorage.removeItem(key);
+        } else {
             window.sessionStorage.removeItem(key);
+        }
         return Promise.resolve();
     }
 }