1 files changed, 79 insertions, 0 deletions
diff --git a/gae/frontend/src/app/menu/menu_base.ts b/gae/frontend/src/app/menu/menu_base.ts
new file mode 100644
index 0000000..4d68f03
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+++ b/gae/frontend/src/app/menu/menu_base.ts
@@ -0,0 +1,79 @@
+/**
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * 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.
+ */
+
+/** This class defines and/or implements the common properties and methods
+ * used among menus.
+ */
+import { AppService } from '../appservice';
+import { MatSnackBar } from '@angular/material';
+import moment from 'moment-timezone';
+
+
+export abstract class MenuBaseClass {
+  count = -1;
+
+  loading = false;
+  pageSizeOptions = [20, 50, 100, 200];
+  pageSize = 100;
+  pageIndex = 0;
+
+  protected constructor(private appService: AppService,
+                        public snackBar: MatSnackBar) {
+    this.appService.closeSideNav();
+    this.snackBar.dismiss();
+  }
+
+  /** Returns an Observable which handles a response of count API.
+   * @param additionalOperations A list of lambda functions.
+   */
+  getDefaultCountObservable(additionalOperations: any[] = []) {
+    return {
+      next: (response) => {
+        this.count = response.count;
+        for (const operation of additionalOperations) {
+          operation(response);
+        }
+      },
+      error: (error) => this.showSnackbar(`[${error.status}] ${error.name}`)
+    };
+  }
+
+  getRelativeTime(timeString) {
+    return (moment.tz(timeString, 'YYYY-MM-DDThh:mm:ss', 'UTC').isValid() ?
+      moment.tz(timeString, 'YYYY-MM-DDThh:mm:ss', 'UTC').fromNow() : '---');
+  }
+
+  /** Checks whether timeString is expired from current time. */
+  isExpired(timeString, hours=72) {
+    let currentTime = moment.tz(timeString, 'YYYY-MM-DDThh:mm:ss', 'UTC');
+    if (!currentTime.isValid()) { return false; }
+
+    let diff = moment().diff(currentTime);
+    let duration = moment.duration(diff);
+    return duration.asHours() > hours;
+  }
+
+  /** Displays a snackbar notification. */
+  showSnackbar(message = 'Error', duration = 5000) {
+    this.loading = false;
+    this.snackBar.open(message, 'DISMISS', {duration});
+  }
+
+  /** Displays a side nav window and lists all properties of selected entity. */
+  onShowDetailsClicked(entity) {
+    this.appService.showDetails(entity);
+  }
+}