From 9e318a6bde15fb72b8a800b5f12de43f4b79172b Mon Sep 17 00:00:00 2001
From: Alexandr Velikiy <39257464+VargBurz@users.noreply.github.com>
Date: Wed, 30 Oct 2019 16:05:12 +0300
Subject: [PATCH] Error while saving analytic unit: this._datasourceRequest is
 undefined #207 (#390)

---
 src/panel/graph_panel/models/metric.ts | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/panel/graph_panel/models/metric.ts b/src/panel/graph_panel/models/metric.ts
index d0d6470..2efa762 100644
--- a/src/panel/graph_panel/models/metric.ts
+++ b/src/panel/graph_panel/models/metric.ts
@@ -28,6 +28,9 @@ export class MetricExpanded {
   private _targets: Target[];
   constructor(public datasource: string, targets: any[]) {
     const visibleTargets = targets.filter(target => !target.hide);
+    if(visibleTargets.length === 0) {
+      throw new Error('There are no visible metrics. Please add at least one metric');
+    }
     if(visibleTargets.length > 1) {
       throw new Error('Multiple metrics are not supported currently');
     }