Merge pull request #86 from quickwit-oss/ddelemeny/skip-empty-frames

Skip processing when frame is empty

Author: fmassot

src/datasource/processResponse.ts

@@ -1,4 +1,4 @@
-import { DataFrame, DataLink, DataQueryRequest, DataQueryResponse, FieldType } from "@grafana/data";
+import { DataFrame, DataLink, DataQueryRequest, DataQueryResponse, Field, FieldType } from "@grafana/data";
 import { getDataSourceSrv } from "@grafana/runtime";
 import { QuickwitDataSource } from 'datasource';
 import { DataLinkConfig, ElasticsearchQuery } from "../types";
@@ -22,6 +22,10 @@ export function processLogsDataFrame(datasource: QuickwitDataSource, dataFrame:
   if (!dataFrame.refId || dataFrame.refId.startsWith('log-volume')) {
     return;
   }
+  // Skip empty dataframes
+  if (dataFrame.length===0 || dataFrame.fields.length === 0) {
+    return;
+  }
   if (datasource.logMessageField) {
     const messageFields = datasource.logMessageField.split(',');
     let field_idx_list = [];
@@ -45,7 +49,7 @@ export function processLogsDataFrame(datasource: QuickwitDataSource, dataFrame:
       displayedMessages[idx] = displayedMessage.trim();
     }
 
-    const newField = {
+    const newField: Field = {
       name: getCustomFieldName('message'),
       type: FieldType.string,
       config: {},