[Data Explorer] State management + enhancements (#4580)

* Adds toggle between legacy and new discover

Signed-off-by: Ashwin P Chandran <ashwinpc@amazon.com>

* Fixes header offset

Signed-off-by: Ashwin P Chandran <ashwinpc@amazon.com>

* adds basic state management

Signed-off-by: Ashwin P Chandran <ashwinpc@amazon.com>

* attempt 1 at dynamic  state management

Signed-off-by: Ashwin P Chandran <ashwinpc@amazon.com>

* Working multi view state management

Signed-off-by: Ashwin P Chandran <ashwinpc@amazon.com>

* Adds global state persistence to data explorer

Signed-off-by: Ashwin P Chandran <ashwinpc@amazon.com>

---------

Signed-off-by: Ashwin P Chandran <ashwinpc@amazon.com>

src/plugins/data_explorer/opensearch_dashboards.json

@@ -4,7 +4,15 @@
   "opensearchDashboardsVersion": "opensearchDashboards",
   "server": true,
   "ui": true,
-  "requiredPlugins": ["data", "navigation"],
+  "requiredPlugins": [
+    "data",
+    "navigation",
+    "embeddable",
+    "expressions"
+  ],
   "optionalPlugins": [],
-  "requiredBundles": ["opensearchDashboardsReact"]
-}
+  "requiredBundles": [
+    "opensearchDashboardsReact",
+    "opensearchDashboardsUtils"
+  ]
+}

src/plugins/data_explorer/public/application.tsx

@@ -5,28 +5,33 @@
 
 import React from 'react';
 import ReactDOM from 'react-dom';
+import { Provider as ReduxProvider } from 'react-redux';
 import { Router, Route, Switch } from 'react-router-dom';
 import { AppMountParameters, CoreStart } from '../../../core/public';
 import { OpenSearchDashboardsContextProvider } from '../../opensearch_dashboards_react/public';
 import { DataExplorerServices } from './types';
 import { DataExplorerApp } from './components/app';
+import { Store } from './utils/state_management';
 
 export const renderApp = (
-  { notifications, http }: CoreStart,
+  core: CoreStart,
   services: DataExplorerServices,
-  params: AppMountParameters
+  params: AppMountParameters,
+  store: Store
 ) => {
   const { history, element } = params;
   ReactDOM.render(
     <Router history={history}>
       <OpenSearchDashboardsContextProvider services={services}>
-        <services.i18n.Context>
-          <Switch>
-            <Route path={[`/:appId`, '/']} exact={false}>
-              <DataExplorerApp params={params} />
-            </Route>
-          </Switch>
-        </services.i18n.Context>
+        <ReduxProvider store={store}>
+          <services.i18n.Context>
+            <Switch>
+              <Route path={[`/:appId`, '/']} exact={false}>
+                <DataExplorerApp params={params} />
+              </Route>
+            </Switch>
+          </services.i18n.Context>
+        </ReduxProvider>
       </OpenSearchDashboardsContextProvider>
     </Router>,
     element

src/plugins/data_explorer/public/components/app_container.tsx

@@ -3,73 +3,31 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import React, { useLayoutEffect, useRef, useState } from 'react';
+import React from 'react';
 import { EuiPageTemplate } from '@elastic/eui';
+import { Suspense } from 'react';
 import { AppMountParameters } from '../../../../core/public';
 import { Sidebar } from './sidebar';
 import { NoView } from './no_view';
 import { View } from '../services/view_service/view';
 
 export const AppContainer = ({ view, params }: { view?: View; params: AppMountParameters }) => {
-  const [showSpinner, setShowSpinner] = useState(false);
-  const canvasRef = useRef<HTMLDivElement>(null);
-  const panelRef = useRef<HTMLDivElement>(null);
-  const unmountRef = useRef<any>(null);
-
-  useLayoutEffect(() => {
-    const unmount = () => {
-      if (unmountRef.current) {
-        unmountRef.current();
-        unmountRef.current = null;
-      }
-    };
-
-    // Do nothing if the view is not defined or if the view is the same as the previous view
-    if (!view || (unmountRef.current && unmountRef.current.viewId === view.id)) {
-      return;
-    }
-
-    // unmount the previous view
-    unmount();
-
-    const mount = async () => {
-      setShowSpinner(true);
-      try {
-        unmountRef.current =
-          (await view.mount({
-            canvasElement: canvasRef.current!,
-            panelElement: panelRef.current!,
-            appParams: params,
-          })) || null;
-      } catch (e) {
-        // TODO: add error UI
-        // eslint-disable-next-line no-console
-        console.error(e);
-      } finally {
-        // if (canvasRef.current && panelRef.current) {
-        if (canvasRef.current) {
-          setShowSpinner(false);
-        }
-      }
-    };
-
-    mount();
-
-    return unmount;
-  }, [params, view]);
-
   // TODO: Make this more robust.
   if (!view) {
     return <NoView />;
   }
 
+  const { Canvas, Panel } = view;
+
   // Render the application DOM.
   // Note that `navigation.ui.TopNavMenu` is a stateful component exported on the `navigation` plugin's start contract.
   return (
     <EuiPageTemplate
       pageSideBar={
         <Sidebar>
-          <div ref={panelRef} />
+          <Suspense fallback={<div>Loading...</div>}>
+            <Panel {...params} />
+          </Suspense>
         </Sidebar>
       }
       className="dePageTemplate"
@@ -78,8 +36,9 @@ export const AppContainer = ({ view, params }: { view?: View; params: AppMountPa
       paddingSize="none"
     >
       {/* TODO: improve loading state */}
-      {showSpinner && <div>Loading...</div>}
-      <div key={view.id} ref={canvasRef} />
+      <Suspense fallback={<div>Loading...</div>}>
+        <Canvas {...params} />
+      </Suspense>
     </EuiPageTemplate>
   );
 };

src/plugins/data_explorer/public/components/sidebar/index.tsx

@@ -0,0 +1,99 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import React, { useMemo, FC, useEffect, useState } from 'react';
+import { i18n } from '@osd/i18n';
+import { EuiPanel, EuiComboBox, EuiSelect, EuiComboBoxOptionOption } from '@elastic/eui';
+import { useOpenSearchDashboards } from '../../../../opensearch_dashboards_react/public';
+import { useView } from '../../utils/use';
+import { DataExplorerServices } from '../../types';
+import { useTypedDispatch, useTypedSelector, setIndexPattern } from '../../utils/state_management';
+import { setView } from '../../utils/state_management/metadata_slice';
+
+export const Sidebar: FC = ({ children }) => {
+  const { indexPattern: indexPatternId } = useTypedSelector((state) => state.metadata);
+  const dispatch = useTypedDispatch();
+  const [options, setOptions] = useState<Array<EuiComboBoxOptionOption<string>>>([]);
+  const [selectedOption, setSelectedOption] = useState<EuiComboBoxOptionOption<string>>();
+  const { view, viewRegistry } = useView();
+  const views = viewRegistry.all();
+  const viewOptions = useMemo(
+    () =>
+      views.map(({ id, title }) => ({
+        value: id,
+        text: title,
+      })),
+    [views]
+  );
+
+  const {
+    services: {
+      data: { indexPatterns },
+      notifications: { toasts },
+    },
+  } = useOpenSearchDashboards<DataExplorerServices>();
+
+  useEffect(() => {
+    const fetchIndexPatterns = async () => {
+      await indexPatterns.ensureDefaultIndexPattern();
+      const cache = await indexPatterns.getCache();
+      const currentOptions = (cache || []).map((indexPattern) => ({
+        label: indexPattern.attributes.title,
+        value: indexPattern.id,
+      }));
+      setOptions(currentOptions);
+    };
+    fetchIndexPatterns();
+  }, [indexPatterns]);
+
+  // Set option to the current index pattern
+  useEffect(() => {
+    if (indexPatternId) {
+      const option = options.find((o) => o.value === indexPatternId);
+      setSelectedOption(option);
+    }
+  }, [indexPatternId, options]);
+
+  return (
+    <>
+      <EuiPanel borderRadius="none" hasShadow={false}>
+        <EuiComboBox
+          placeholder="Select a datasource"
+          singleSelection={{ asPlainText: true }}
+          options={options}
+          selectedOptions={selectedOption ? [selectedOption] : []}
+          onChange={(selected) => {
+            // TODO: There are many issues with this approach, but it's a start
+            // 1. Combo box can delete a selected index pattern. This should not be possible
+            // 2. Combo box is severely truncated. This should be fixed in the EUI component
+            // 3. The onchange can fire with a option that is not valid. discuss where to handle this.
+            // 4. value is optional. If the combobox needs to act as a slecet, this should be required.
+            const { value } = selected[0] || {};
+
+            if (!value) {
+              toasts.addWarning({
+                id: 'index-pattern-not-found',
+                title: i18n.translate('dataExplorer.indexPatternError', {
+                  defaultMessage: 'Index pattern not found',
+                }),
+              });
+              return;
+            }
+
+            dispatch(setIndexPattern(value));
+          }}
+        />
+        <EuiSelect
+          options={viewOptions}
+          value={view?.id}
+          onChange={(e) => {
+            dispatch(setView(e.target.value));
+          }}
+        />
+      </EuiPanel>
+      {children}
+    </>
+  );
+};

src/plugins/data_explorer/public/index.ts

@@ -13,4 +13,5 @@ export function plugin() {
   return new DataExplorerPlugin();
 }
 export { DataExplorerPluginSetup, DataExplorerPluginStart, ViewRedirectParams } from './types';
-export { ViewMountParameters, ViewDefinition } from './services/view_service';
+export { ViewProps, ViewDefinition } from './services/view_service';
+export { RootState, useTypedSelector, useTypedDispatch } from './utils/state_management';