Transformations: Make sidebar subscribe to panel's query runner (#23785)

* Make panel edit sidebar options use lates data from panel query runner

* Update select's z-index

* Review

public/app/features/dashboard/components/PanelEditor/OptionsPaneContent.tsx

 import React, { useCallback, useState, CSSProperties } from 'react';
 import Transition from 'react-transition-group/Transition';
-import { FieldConfigSource, GrafanaTheme, PanelData, PanelPlugin, SelectableValue } from '@grafana/data';
+import { FieldConfigSource, GrafanaTheme, PanelPlugin, SelectableValue } from '@grafana/data';
 import { DashboardModel, PanelModel } from '../../state';
 import { CustomScrollbar, stylesFactory, Tab, TabContent, TabsBar, Select, useTheme, Icon, Input } from '@grafana/ui';
 import { DefaultFieldConfigEditor, OverrideFieldConfigEditor } from './FieldConfigEditor';
 import { css } from 'emotion';
 import { PanelOptionsTab } from './PanelOptionsTab';
 import { DashNavButton } from 'app/features/dashboard/components/DashNav/DashNavButton';
+import { usePanelLatestData } from './usePanelLatestData';
 
 interface Props {
   plugin: PanelPlugin;
   panel: PanelModel;
-  data: PanelData;
   width: number;
   dashboard: DashboardModel;
   onClose: () => void;
@@ -23,7 +23,6 @@ interface Props {
 export const OptionsPaneContent: React.FC<Props> = ({
   plugin,
   panel,
-  data,
   width,
   onFieldConfigsChange,
   onPanelOptionsChanged,
@@ -35,12 +34,13 @@ export const OptionsPaneContent: React.FC<Props> = ({
   const styles = getStyles(theme);
   const [activeTab, setActiveTab] = useState('options');
   const [isSearching, setSearchMode] = useState(false);
+  const [currentData, hasSeries] = usePanelLatestData(panel);
 
   const renderFieldOptions = useCallback(
     (plugin: PanelPlugin) => {
       const fieldConfig = panel.getFieldConfig();
 
-      if (!fieldConfig) {
+      if (!fieldConfig || !hasSeries) {
         return null;
       }
 
@@ -49,18 +49,18 @@ export const OptionsPaneContent: React.FC<Props> = ({
           config={fieldConfig}
           plugin={plugin}
           onChange={onFieldConfigsChange}
-          data={data.series}
+          data={currentData.series}
         />
       );
     },
-    [data, plugin, panel, onFieldConfigsChange]
+    [currentData, plugin, panel, onFieldConfigsChange]
   );
 
   const renderFieldOverrideOptions = useCallback(
     (plugin: PanelPlugin) => {
       const fieldConfig = panel.getFieldConfig();
 
-      if (!fieldConfig) {
+      if (!fieldConfig || !hasSeries) {
         return null;
       }
 
@@ -69,11 +69,11 @@ export const OptionsPaneContent: React.FC<Props> = ({
           config={fieldConfig}
           plugin={plugin}
           onChange={onFieldConfigsChange}
-          data={data.series}
+          data={currentData.series}
         />
       );
     },
-    [data, plugin, panel, onFieldConfigsChange]
+    [currentData, plugin, panel, onFieldConfigsChange]
   );
 
   // When the panel has no query only show the main tab
@@ -103,7 +103,7 @@ export const OptionsPaneContent: React.FC<Props> = ({
                   panel={panel}
                   plugin={plugin}
                   dashboard={dashboard}
-                  data={data}
+                  data={currentData}
                   onPanelConfigChange={onPanelConfigChange}
                   onFieldConfigsChange={onFieldConfigsChange}
                   onPanelOptionsChanged={onPanelOptionsChanged}

public/app/features/dashboard/components/PanelEditor/PanelEditor.tsx

@@ -275,7 +275,7 @@ export class PanelEditorUnconnected extends PureComponent<Props> {
   }
 
   renderOptionsPane() {
-    const { plugin, dashboard, data, panel, uiState } = this.props;
+    const { plugin, dashboard, panel, uiState } = this.props;
 
     if (!plugin) {
       return <div />;
@@ -285,7 +285,6 @@ export class PanelEditorUnconnected extends PureComponent<Props> {
       <OptionsPaneContent
         plugin={plugin}
         dashboard={dashboard}
-        data={data}
         panel={panel}
         width={uiState.rightPaneSize as number}
         onClose={this.onTogglePanelOptions}

public/app/features/dashboard/components/PanelEditor/usePanelLatestData.ts

+import { PanelData } from '@grafana/data';
+import { useEffect, useRef, useState } from 'react';
+import { PanelModel } from '../../state';
+import { Unsubscribable } from 'rxjs';
+
+export const usePanelLatestData = (panel: PanelModel): [PanelData | null, boolean] => {
+  const querySubscription = useRef<Unsubscribable>(null);
+  const [latestData, setLatestData] = useState<PanelData>(null);
+
+  useEffect(() => {
+    querySubscription.current = panel
+      .getQueryRunner()
+      .getData()
+      .subscribe({
+        next: data => setLatestData(data),
+      });
+
+    return () => {
+      if (querySubscription.current) {
+        console.log('unsubscribing');
+        querySubscription.current.unsubscribe();
+      }
+    };
+  }, [panel]);
+
+  return [
+    latestData,
+    // TODO: make this more clever, use PanelData.state
+    !!(latestData && latestData.series),
+  ];
+};