[Discover] Modify columns and sort when switching index pattern (#74336)

* Modify columns and sort when switching index pattern

* Add unit tests

* Add uiSetting to allow switch to legacy behavior

src/plugins/discover/common/index.ts

@@ -27,3 +27,4 @@ export const FIELDS_LIMIT_SETTING = 'fields:popularLimit';
 export const CONTEXT_DEFAULT_SIZE_SETTING = 'context:defaultSize';
 export const CONTEXT_STEP_SETTING = 'context:step';
 export const CONTEXT_TIE_BREAKER_FIELDS_SETTING = 'context:tieBreakerFields';
+export const MODIFY_COLUMNS_ON_SWITCH = 'discover:modifyColumnsOnSwitch';

src/plugins/discover/public/application/angular/discover.js

@@ -71,7 +71,7 @@ const {
 import { getRootBreadcrumbs, getSavedSearchBreadcrumbs } from '../helpers/breadcrumbs';
 import { validateTimeRange } from '../helpers/validate_time_range';
 import { popularizeField } from '../helpers/popularize_field';
-
+import { getSwitchIndexPatternAppState } from '../helpers/get_switch_index_pattern_app_state';
 import { getIndexPatternId } from '../helpers/get_index_pattern_id';
 import { addFatalError } from '../../../../kibana_legacy/public';
 import {
@@ -80,6 +80,7 @@ import {
   SORT_DEFAULT_ORDER_SETTING,
   SEARCH_ON_PAGE_LOAD_SETTING,
   DOC_HIDE_TIME_COLUMN_SETTING,
+  MODIFY_COLUMNS_ON_SWITCH,
 } from '../../../common';
 
 const fetchStatuses = {
@@ -253,6 +254,11 @@ function discoverController($element, $route, $scope, $timeout, $window, Promise
 
     if (!_.isEqual(newStatePartial, oldStatePartial)) {
       $scope.$evalAsync(async () => {
+        if (oldStatePartial.index !== newStatePartial.index) {
+          //in case of index switch the route has currently to be reloaded, legacy
+          return;
+        }
+
         $scope.state = { ...newState };
 
         // detect changes that should trigger fetching of new data
@@ -277,8 +283,18 @@ function discoverController($element, $route, $scope, $timeout, $window, Promise
   });
 
   $scope.setIndexPattern = async (id) => {
-    await replaceUrlAppState({ index: id });
-    $route.reload();
+    const nextIndexPattern = await indexPatterns.get(id);
+    if (nextIndexPattern) {
+      const nextAppState = getSwitchIndexPatternAppState(
+        $scope.indexPattern,
+        nextIndexPattern,
+        $scope.state.columns,
+        $scope.state.sort,
+        config.get(MODIFY_COLUMNS_ON_SWITCH)
+      );
+      await replaceUrlAppState(nextAppState);
+      $route.reload();
+    }
   };
 
   // update data source when filters update

src/plugins/discover/public/application/helpers/get_switch_index_pattern_app_state.test.ts

@@ -0,0 +1,90 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { getSwitchIndexPatternAppState } from './get_switch_index_pattern_app_state';
+import { IIndexPatternFieldList, IndexPattern } from '../../../../data/common/index_patterns';
+
+const currentIndexPattern: IndexPattern = {
+  id: 'prev',
+  getFieldByName(name) {
+    return this.fields.getByName(name);
+  },
+  fields: {
+    getByName: (name: string) => {
+      const fields = [
+        { name: 'category', sortable: true },
+        { name: 'name', sortable: true },
+      ] as IIndexPatternFieldList;
+      return fields.find((field) => field.name === name);
+    },
+  },
+} as IndexPattern;
+
+const nextIndexPattern = {
+  id: 'next',
+  getFieldByName(name) {
+    return this.fields.getByName(name);
+  },
+  fields: {
+    getByName: (name: string) => {
+      const fields = [{ name: 'category', sortable: true }] as IIndexPatternFieldList;
+      return fields.find((field) => field.name === name);
+    },
+  },
+} as IndexPattern;
+
+describe('Discover getSwitchIndexPatternAppState', () => {
+  test('removing fields that are not part of the next index pattern, keeping unknown fields ', async () => {
+    const result = getSwitchIndexPatternAppState(
+      currentIndexPattern,
+      nextIndexPattern,
+      ['category', 'name', 'unknown'],
+      [['category', 'desc']]
+    );
+    expect(result.columns).toEqual(['category', 'unknown']);
+    expect(result.sort).toEqual([['category', 'desc']]);
+  });
+  test('removing sorted by fields that are not part of the next index pattern', async () => {
+    const result = getSwitchIndexPatternAppState(
+      currentIndexPattern,
+      nextIndexPattern,
+      ['name'],
+      [
+        ['category', 'desc'],
+        ['name', 'asc'],
+      ]
+    );
+    expect(result.columns).toEqual(['_source']);
+    expect(result.sort).toEqual([['category', 'desc']]);
+  });
+  test('removing sorted by fields that without modifying columns', async () => {
+    const result = getSwitchIndexPatternAppState(
+      currentIndexPattern,
+      nextIndexPattern,
+      ['name'],
+      [
+        ['category', 'desc'],
+        ['name', 'asc'],
+      ],
+      false
+    );
+    expect(result.columns).toEqual(['name']);
+    expect(result.sort).toEqual([['category', 'desc']]);
+  });
+});

src/plugins/discover/public/application/helpers/get_switch_index_pattern_app_state.ts

@@ -0,0 +1,46 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+import { getSortArray } from '../angular/doc_table';
+import { SortPairArr } from '../angular/doc_table/lib/get_sort';
+import { IndexPattern } from '../../kibana_services';
+
+/**
+ * Helper function to remove or adapt the currently selected columns/sort to be valid with the next
+ * index pattern, returns a new state object
+ */
+export function getSwitchIndexPatternAppState(
+  currentIndexPattern: IndexPattern,
+  nextIndexPattern: IndexPattern,
+  currentColumns: string[],
+  currentSort: SortPairArr[],
+  modifyColumns: boolean = true
+) {
+  const nextColumns = modifyColumns
+    ? currentColumns.filter(
+        (column) =>
+          nextIndexPattern.fields.getByName(column) || !currentIndexPattern.fields.getByName(column)
+      )
+    : currentColumns;
+  const nextSort = getSortArray(currentSort, nextIndexPattern);
+  return {
+    index: nextIndexPattern.id,
+    columns: nextColumns.length ? nextColumns : ['_source'],
+    sort: nextSort,
+  };
+}

src/plugins/discover/server/ui_settings.ts

@@ -32,6 +32,7 @@ import {
   CONTEXT_DEFAULT_SIZE_SETTING,
   CONTEXT_STEP_SETTING,
   CONTEXT_TIE_BREAKER_FIELDS_SETTING,
+  MODIFY_COLUMNS_ON_SWITCH,
 } from '../common';
 
 export const uiSettings: Record<string, UiSettingsParams> = {
@@ -163,4 +164,15 @@ export const uiSettings: Record<string, UiSettingsParams> = {
     category: ['discover'],
     schema: schema.arrayOf(schema.string()),
   },
+  [MODIFY_COLUMNS_ON_SWITCH]: {
+    name: i18n.translate('discover.advancedSettings.discover.modifyColumnsOnSwitchTitle', {
+      defaultMessage: 'Modify columns when changing index patterns',
+    }),
+    value: true,
+    description: i18n.translate('discover.advancedSettings.discover.modifyColumnsOnSwitchText', {
+      defaultMessage: 'Remove columns that not available in the new index pattern.',
+    }),
+    category: ['discover'],
+    schema: schema.boolean(),
+  },
 };