Improve state code

src/plugins/discover/public/application/apps/main/discover_main_app.tsx

@@ -71,7 +71,6 @@ export function DiscoverMainApp(props: DiscoverMainProps) {
     services,
     history,
     savedSearch,
-    indexPatternList,
   });
 
   /**

src/plugins/discover/public/application/apps/main/services/use_discover_state.ts

@@ -13,10 +13,10 @@ import { getStateDefaults } from '../utils/get_state_defaults';
 import { DiscoverServices } from '../../../../build_services';
 import { SavedSearch } from '../../../../saved_searches';
 import { useSavedSearch as useSavedSearchData } from './use_saved_search';
-import { SEARCH_FIELDS_FROM_SOURCE, SEARCH_ON_PAGE_LOAD_SETTING } from '../../../../../common';
+import { SEARCH_FIELDS_FROM_SOURCE } from '../../../../../common';
 import { useSearchSession } from './use_search_session';
-import { FetchStatus } from '../../../types';
 import { DiscoverContext } from './discover_context';
+import { IndexPattern } from '../../../../../../data_views/common';
 
 export function useDiscoverState({
   services,
@@ -28,23 +28,24 @@ export function useDiscoverState({
   history: History;
 }) {
   const { uiSettings: config, data } = services;
-  const useNewFieldsApi = useMemo(() => !config.get(SEARCH_FIELDS_FROM_SOURCE), [config]);
-  const { timefilter } = data.query.timefilter;
-  const [indexPattern, setIndexPattern] = useState(savedSearch.searchSource.getField('index'));
-
   const {
     dataViews: { get },
   } = useContext(DiscoverContext);
 
+  const useNewFieldsApi = useMemo(() => !config.get(SEARCH_FIELDS_FROM_SOURCE), [config]);
+  const [indexPattern, setIndexPattern] = useState<IndexPattern | undefined>();
   const searchSource = useMemo(() => savedSearch.searchSource.createChild(), [savedSearch]);
 
   const stateContainer = useMemo(() => getState({ history, services }), [services, history]);
   const [state, setState] = useState(stateContainer.appStateContainer.getState());
 
   const { appStateContainer } = stateContainer;
 
+  /**
+   * Load index pattern
+   */
   useEffect(() => {
-    const load = async () => {
+    const loadIndexPattern = async () => {
       if (!savedSearch?.searchSource.getField('index')) {
         const { index, timefield } = appStateContainer.getState();
         const loadedIndexPattern = await get(
@@ -57,30 +58,19 @@ export function useDiscoverState({
         setIndexPattern(savedSearch?.searchSource.getField('index'));
       }
     };
-    load();
+    loadIndexPattern();
   }, [appStateContainer, get, savedSearch.searchSource, services.uiSettings]);
 
   /**
    * Search session logic
    */
   const searchSessionManager = useSearchSession({ services, history, stateContainer, savedSearch });
 
-  const initialFetchStatus: FetchStatus = useMemo(() => {
-    // A saved search is created on every page load, so we check the ID to see if we're loading a
-    // previously saved search or if it is just transient
-    const shouldSearchOnPageLoad =
-      config.get<boolean>(SEARCH_ON_PAGE_LOAD_SETTING) ||
-      savedSearch.id !== undefined ||
-      timefilter.getRefreshInterval().pause === false ||
-      searchSessionManager.hasSearchSessionIdInURL();
-    return shouldSearchOnPageLoad ? FetchStatus.LOADING : FetchStatus.UNINITIALIZED;
-  }, [config, savedSearch.id, searchSessionManager, timefilter]);
-
   /**
    * Data fetching logic
    */
   const { data$, refetch$, reset, inspectorAdapters } = useSavedSearchData({
-    initialFetchStatus,
+    savedSearch,
     searchSessionManager,
     searchSource,
     services,
@@ -92,7 +82,7 @@ export function useDiscoverState({
    * Start syncing of state to URL of state if searchSource is complete (existing index pattern)
    */
   useEffect(() => {
-    if (savedSearch.searchSource.getField('index')) {
+    if (indexPattern && savedSearch.searchSource.getField('index') === indexPattern) {
       const prevState = stateContainer.appStateContainer.getState();
       const stopSync = stateContainer.initializeAndSync(savedSearch);
       const nextState = stateContainer.appStateContainer.getState();
@@ -194,7 +184,7 @@ export function useDiscoverState({
     if (indexPattern) {
       refetch$.next();
     }
-  }, [initialFetchStatus, refetch$, indexPattern, savedSearch.id]);
+  }, [refetch$, indexPattern, savedSearch.id]);
 
   return {
     data$,

src/plugins/discover/public/application/apps/main/services/use_saved_search.ts

@@ -23,6 +23,8 @@ import { fetchAll } from '../utils/fetch_all';
 import { useBehaviorSubject } from '../utils/use_behavior_subject';
 import { sendResetMsg } from './use_saved_search_messages';
 import { getFetch$ } from '../utils/get_fetch_observable';
+import { SavedSearch } from '../../../../saved_searches';
+import { getInitialFetchStatus } from '../utils/get_initial_fetch_status';
 
 export interface SavedSearchData {
   main$: DataMain$;
@@ -82,36 +84,48 @@ export interface DataChartsMessage extends DataMsg {
  * to the data fetching
  */
 export const useSavedSearch = ({
-  initialFetchStatus,
   searchSessionManager,
+  savedSearch,
   searchSource,
   services,
   stateContainer,
   useNewFieldsApi,
 }: {
-  initialFetchStatus: FetchStatus;
   searchSessionManager: DiscoverSearchSessionManager;
+  savedSearch: SavedSearch;
   searchSource: SearchSource;
   services: DiscoverServices;
   stateContainer: GetStateReturn;
   useNewFieldsApi: boolean;
 }) => {
-  const { data, filterManager } = services;
+  const { data } = services;
   const timefilter = data.query.timefilter.timefilter;
 
+  const initialFetchStatus: FetchStatus = useMemo(() => {
+    // A saved search is created on every page load, so we check the ID to see if we're loading a
+    // previously saved search or if it is just transient
+    return getInitialFetchStatus(savedSearch, searchSessionManager, services);
+  }, [savedSearch, searchSessionManager, services]);
+
   const inspectorAdapters = useMemo(() => ({ requests: new RequestAdapter() }), []);
 
   /**
    * The observables the UI (aka React component) subscribes to get notified about
    * the changes in the data fetching process (high level: fetching started, data was received)
    */
-  const main$: DataMain$ = useBehaviorSubject({ fetchStatus: initialFetchStatus });
+  const main$: DataMain$ = useBehaviorSubject({ fetchStatus: initialFetchStatus } as DataMainMsg);
 
-  const documents$: DataDocuments$ = useBehaviorSubject({ fetchStatus: initialFetchStatus });
+  const documents$: DataDocuments$ = useBehaviorSubject({
+    fetchStatus: initialFetchStatus,
+  } as DataDocumentsMsg);
 
-  const totalHits$: DataTotalHits$ = useBehaviorSubject({ fetchStatus: initialFetchStatus });
+  const totalHits$: DataTotalHits$ = useBehaviorSubject({
+    fetchStatus: initialFetchStatus,
+  } as DataTotalHitsMsg);
 
-  const charts$: DataCharts$ = useBehaviorSubject({ fetchStatus: initialFetchStatus });
+  const charts$: DataCharts$ = useBehaviorSubject({
+    fetchStatus: initialFetchStatus,
+  } as DataChartsMessage);
 
   const dataSubjects = useMemo(() => {
     return {
@@ -195,18 +209,14 @@ export const useSavedSearch = ({
     return () => subscription.unsubscribe();
   }, [
     data,
-    data.query.queryString,
     dataSubjects,
-    filterManager,
     initialFetchStatus,
     inspectorAdapters,
     main$,
     refetch$,
     searchSessionManager,
-    searchSessionManager.newSearchSessionIdFromURL$,
     searchSource,
     services,
-    services.toastNotifications,
     stateContainer.appStateContainer,
     timefilter,
     useNewFieldsApi,

src/plugins/discover/public/application/apps/main/utils/get_initial_fetch_status.ts

@@ -0,0 +1,26 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+import { SEARCH_ON_PAGE_LOAD_SETTING } from '../../../../../common';
+import { FetchStatus } from '../../../types';
+import { DiscoverServices } from '../../../../build_services';
+import { DiscoverSearchSessionManager } from '../services/discover_search_session';
+import { SavedSearch } from '../../../../saved_searches';
+
+export function getInitialFetchStatus(
+  savedSearch: SavedSearch,
+  searchSessionManager: DiscoverSearchSessionManager,
+  services: DiscoverServices
+) {
+  const { timefilter } = services.data.query.timefilter;
+  const shouldSearchOnPageLoad =
+    services.uiSettings.get<boolean>(SEARCH_ON_PAGE_LOAD_SETTING) ||
+    savedSearch.id !== undefined ||
+    timefilter.getRefreshInterval().pause === false ||
+    searchSessionManager.hasSearchSessionIdInURL();
+  return shouldSearchOnPageLoad ? FetchStatus.LOADING : FetchStatus.UNINITIALIZED;
+}