From 1a38c45dde08335086d0c432a40255e30b4d1607 Mon Sep 17 00:00:00 2001
From: David Kaltschmidt <david.kaltschmidt@gmail.com>
Date: Fri, 14 Sep 2018 16:09:43 +0200
Subject: [PATCH] Hotfix for Explore (empty page after running query)

Since #13212 adhoc filters are being gathered, in Explore the template
  service has no variables set and then throws when iterating over them.
---
 .../app/features/templating/template_srv.ts   | 22 ++++++++++---------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/public/app/features/templating/template_srv.ts b/public/app/features/templating/template_srv.ts
index def9fda1f56..70fd287402f 100644
--- a/public/app/features/templating/template_srv.ts
+++ b/public/app/features/templating/template_srv.ts
@@ -50,18 +50,20 @@ export class TemplateSrv {
   getAdhocFilters(datasourceName) {
     let filters = [];
 
-    for (let i = 0; i < this.variables.length; i++) {
-      const variable = this.variables[i];
-      if (variable.type !== 'adhoc') {
-        continue;
-      }
+    if (this.variables) {
+      for (let i = 0; i < this.variables.length; i++) {
+        const variable = this.variables[i];
+        if (variable.type !== 'adhoc') {
+          continue;
+        }
 
-      // null is the "default" datasource
-      if (variable.datasource === null || variable.datasource === datasourceName) {
-        filters = filters.concat(variable.filters);
-      } else if (variable.datasource.indexOf('$') === 0) {
-        if (this.replace(variable.datasource) === datasourceName) {
+        // null is the "default" datasource
+        if (variable.datasource === null || variable.datasource === datasourceName) {
           filters = filters.concat(variable.filters);
+        } else if (variable.datasource.indexOf('$') === 0) {
+          if (this.replace(variable.datasource) === datasourceName) {
+            filters = filters.concat(variable.filters);
+          }
         }
       }
     }