minor ds init refactor

dist/datasource-zabbix/datasource.js

@@ -220,26 +220,28 @@ System.register(['lodash', 'app/core/utils/datemath', './utils', './migrations',
           this.basicAuth = instanceSettings.basicAuth;
           this.withCredentials = instanceSettings.withCredentials;
 
+          var jsonData = instanceSettings.jsonData;
+
           // Zabbix API credentials
-          this.username = instanceSettings.jsonData.username;
-          this.password = instanceSettings.jsonData.password;
+          this.username = jsonData.username;
+          this.password = jsonData.password;
 
           // Use trends instead history since specified time
-          this.trends = instanceSettings.jsonData.trends;
-          this.trendsFrom = instanceSettings.jsonData.trendsFrom || '7d';
-          this.trendsRange = instanceSettings.jsonData.trendsRange || '4d';
+          this.trends = jsonData.trends;
+          this.trendsFrom = jsonData.trendsFrom || '7d';
+          this.trendsRange = jsonData.trendsRange || '4d';
 
           // Set cache update interval
-          var ttl = instanceSettings.jsonData.cacheTTL || '1h';
+          var ttl = jsonData.cacheTTL || '1h';
           this.cacheTTL = utils.parseInterval(ttl);
 
           // Alerting options
-          this.alertingEnabled = instanceSettings.jsonData.alerting;
-          this.addThresholds = instanceSettings.jsonData.addThresholds;
-          this.alertingMinSeverity = instanceSettings.jsonData.alertingMinSeverity || c.SEV_WARNING;
+          this.alertingEnabled = jsonData.alerting;
+          this.addThresholds = jsonData.addThresholds;
+          this.alertingMinSeverity = jsonData.alertingMinSeverity || c.SEV_WARNING;
 
           // Direct DB Connection options
-          var dbConnectionOptions = instanceSettings.jsonData.dbConnection || {};
+          var dbConnectionOptions = jsonData.dbConnection || {};
           this.enableDirectDBConnection = dbConnectionOptions.enable;
           this.sqlDatasourceId = dbConnectionOptions.datasourceId;