[Backport 2.x] [osci23] implmented advance setting in Dicover: MODIFY_COLUMN_ON_SWITCH

src/plugins/discover/public/application/view_components/canvas/index.tsx

@@ -18,7 +18,7 @@ import { setColumns, useDispatch, useSelector } from '../../utils/state_manageme
 import { DiscoverViewServices } from '../../../build_services';
 import { useOpenSearchDashboards } from '../../../../../opensearch_dashboards_react/public';
 import { filterColumns } from '../utils/filter_columns';
-import { DEFAULT_COLUMNS_SETTING } from '../../../../common';
+import { DEFAULT_COLUMNS_SETTING, MODIFY_COLUMNS_ON_SWITCH } from '../../../../common';
 import { OpenSearchSearchHit } from '../../../application/doc_views/doc_views_types';
 import './discover_canvas.scss';
 
@@ -32,7 +32,8 @@ export default function DiscoverCanvas({ setHeaderActionMenu, history }: ViewPro
   const filteredColumns = filterColumns(
     columns,
     indexPattern,
-    uiSettings.get(DEFAULT_COLUMNS_SETTING)
+    uiSettings.get(DEFAULT_COLUMNS_SETTING),
+    uiSettings.get(MODIFY_COLUMNS_ON_SWITCH)
   );
   const dispatch = useDispatch();
   const prevIndexPattern = useRef(indexPattern);

src/plugins/discover/public/application/view_components/utils/filter_columns.test.ts

@@ -13,21 +13,32 @@ describe('filterColumns', () => {
     },
   } as IndexPattern;
 
-  it('should return columns that exist in the index pattern fields', () => {
+  it('should return columns that exist in the index pattern fields when MODIFY_COLUMN_ON_SWITCH is true', () => {
     const columns = ['a', 'b'];
-    const result = filterColumns(columns, indexPatternMock, ['a']);
+    const result = filterColumns(columns, indexPatternMock, ['a'], true);
     expect(result).toEqual(['a']);
   });
 
-  it('should return defaultColumns if no columns exist in the index pattern fields', () => {
+  it('should return all of the columns when MODIFY_COLUMN_ON_SWITCH is false', () => {
+    const columns = ['a', 'b'];
+    const result = filterColumns(columns, indexPatternMock, ['a'], false);
+    expect(result).toEqual(['a', 'b']);
+  });
+
+  it('should return defualt columns if columns are empty', () => {
+    const result = filterColumns([], indexPatternMock, ['a'], false);
+    expect(result).toEqual(['_source']);
+  });
+
+  it('should return defaultColumns if no columns exist in the index pattern fields when MODIFY_COLUMN_ON_SWITCH is true', () => {
     const columns = ['b', 'e'];
-    const result = filterColumns(columns, indexPatternMock, ['e']);
+    const result = filterColumns(columns, indexPatternMock, ['e'], true);
     expect(result).toEqual(['_source']);
   });
 
   it('should return defaultColumns if no columns and indexPattern is undefined', () => {
     const columns = ['b', 'e'];
-    const result = filterColumns(columns, undefined, ['a']);
+    const result = filterColumns(columns, undefined, ['a'], true);
     expect(result).toEqual(['_source']);
   });
 });

src/plugins/discover/public/application/view_components/utils/filter_columns.ts

@@ -4,6 +4,7 @@
  */
 
 import { IndexPattern } from '../../../opensearch_dashboards_services';
+import { buildColumns } from '../../utils/columns';
 
 /**
  * Helper function to filter columns based on the fields of the index pattern.
@@ -13,15 +14,23 @@ import { IndexPattern } from '../../../opensearch_dashboards_services';
  * @param columns Array of column names
  * @param indexPattern Index pattern object
  * @param defaultColumns Array of default columns
+ * @param modifyColumn Booelan of 'discover:modifyColumnsOnSwitch'
  */
 export function filterColumns(
   columns: string[],
   indexPattern: IndexPattern | undefined,
-  defaultColumns: string[]
+  defaultColumns: string[],
+  modifyColumn: boolean
 ) {
+  // if false, we keep all the chosen columns
+  if (!modifyColumn) {
+    return columns.length > 0 ? columns : ['_source'];
+  }
+  // if true, we keep columns that exist in the new index pattern
   const fieldsName = indexPattern?.fields.getAll().map((fld) => fld.name) || [];
   // combine columns and defaultColumns without duplicates
   const combinedColumns = [...new Set([...columns, ...defaultColumns])];
   const filteredColumns = combinedColumns.filter((column) => fieldsName.includes(column));
-  return filteredColumns.length > 0 ? filteredColumns : ['_source'];
+  const adjustedColumns = buildColumns(filteredColumns);
+  return adjustedColumns.length > 0 ? adjustedColumns : ['_source'];
 }