[ADF-2626] added preserved state functionality for sidenav component

lib/core/pipes/app-config.pipe.ts

@@ -0,0 +1,39 @@
+/*!
+ * @license
+ * Alfresco Example Content Application
+ *
+ * Copyright (C) 2005 - 2018 Alfresco Software Limited
+ *
+ * This file is part of the Alfresco Example Content Application.
+ * If the software was purchased under a paid Alfresco license, the terms of
+ * the paid license agreement will prevail.  Otherwise, the software is
+ * provided under the following open source license terms:
+ *
+ * The Alfresco Example Content Application is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * The Alfresco Example Content Application 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import { Pipe, PipeTransform } from '@angular/core';
+import { AppConfigService } from './../app-config/app-config.service';
+
+@Pipe({
+    name: 'appConfig',
+    pure: true
+})
+export class AppConfigPipe implements PipeTransform {
+    constructor(private config: AppConfigService) {}
+
+    transform(value: string, fallback: any): any {
+        return this.config.get(value, fallback);
+    }
+}