modify to match discover legacy behavior, columns from previous colum…

…n are only shown in canvas area

Signed-off-by: qiwen li <[email protected]>

src/plugins/discover/public/application/components/sidebar/discover_sidebar.tsx

@@ -103,14 +103,9 @@ export function DiscoverSidebar({
   const uiSettings = services.uiSettings;
 
   useEffect(() => {
-    const newFields = getIndexPatternFieldList(
-      uiSettings.get(MODIFY_COLUMNS_ON_SWITCH),
-      selectedIndexPattern,
-      fieldCounts
-    );
+    const newFields = getIndexPatternFieldList(selectedIndexPattern, fieldCounts);
     setFields(newFields);
-    // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [selectedIndexPattern, fieldCounts, hits, services, uiSettings.get(MODIFY_COLUMNS_ON_SWITCH)]);
+  }, [selectedIndexPattern, fieldCounts, hits, services]);
 
   const onChangeFieldSearch = useCallback(
     (field: string, value: string | boolean | undefined) => {

src/plugins/discover/public/application/components/sidebar/lib/get_index_pattern_field_list.ts

@@ -32,25 +32,9 @@ import { difference } from 'lodash';
 import { IndexPattern, IndexPatternField } from 'src/plugins/data/public';
 
 export function getIndexPatternFieldList(
-  modifyColumn: boolean,
   indexPattern?: IndexPattern,
   fieldCounts?: Record<string, number>
 ) {
   if (!indexPattern || !fieldCounts) return [];
-  if (modifyColumn) {
-    return [...indexPattern.fields.getAll()];
-  }
-  const fieldNamesInDocs = Object.keys(fieldCounts);
-  const fieldNamesInIndexPattern = indexPattern.fields.getAll().map((fld) => fld.name);
-  const unknownTypes: IndexPatternField[] = [];
-
-  difference(fieldNamesInDocs, fieldNamesInIndexPattern).forEach((unknownFieldName) => {
-    unknownTypes.push({
-      displayName: String(unknownFieldName),
-      name: String(unknownFieldName),
-      type: 'unknown',
-    } as IndexPatternField);
-  });
-
-  return [...indexPattern.fields.getAll(), ...unknownTypes];
+  return [...indexPattern.fields.getAll()];
 }