Handle error when loading the dashboard (#862)

* add error tab when the tab cannot be loaded

* formatting

* changing the look for error message per Smitha request

src/sql/parts/dashboard/containers/dashboardErrorContainer.component.ts

@@ -0,0 +1,58 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the Source EULA. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import 'vs/css!./dashboardErrorContainer';
+
+import { Component, Inject, Input, forwardRef, ViewChild, ElementRef, ChangeDetectorRef, AfterViewInit } from '@angular/core';
+
+import { TabConfig } from 'sql/parts/dashboard/common/dashboardWidget';
+import { DashboardTab } from 'sql/parts/dashboard/common/interfaces';
+
+import Event, { Emitter } from 'vs/base/common/event';
+import * as nls from 'vs/nls';
+
+@Component({
+	selector: 'dashboard-error-container',
+	providers: [{ provide: DashboardTab, useExisting: forwardRef(() => DashboardErrorContainer) }],
+	template: `
+		<div class="error-container">
+			<div class="icon globalError">
+			</div>
+			<div class="error-message" #errorMessage>
+			</div>
+		</div>
+	`
+})
+export class DashboardErrorContainer extends DashboardTab implements AfterViewInit {
+	@Input() private tab: TabConfig;
+	private _onResize = new Emitter<void>();
+	public readonly onResize: Event<void> = this._onResize.event;
+
+	@ViewChild('errorMessage', { read: ElementRef }) private _errorMessageContainer: ElementRef;
+	constructor(
+		@Inject(forwardRef(() => ChangeDetectorRef)) protected _cd: ChangeDetectorRef
+	) {
+		super();
+	}
+
+	ngAfterViewInit() {
+		let errorMessage = this._errorMessageContainer.nativeElement as HTMLElement;
+		errorMessage.innerHTML = nls.localize('dashboardNavSection_loadTabError', 'The {0} has an invalid content. Please contact extension owner.', this.tab.title);
+	}
+
+	public get id(): string {
+		return this.tab.id;
+	}
+
+	public get editable(): boolean {
+		return false;
+	}
+
+	public layout() {
+	}
+
+	public refresh(): void {
+	}
+}