EventBus: add origin to all events and support nested EventBus (#33548)

packages/grafana-data/src/events/EventBus.test.ts

@@ -1,4 +1,4 @@
-import { EventBusSrv, EventBusWithSource } from './EventBus';
+import { EventBusSrv } from './EventBus';
 import { BusEvent, BusEventWithPayload } from './types';
 import { eventFactory } from './eventFactory';
 import { DataHoverEvent } from './common';
@@ -50,8 +50,8 @@ describe('EventBus', () => {
   describe('EventBusWithSource', () => {
     it('can add sources to the source path', () => {
       const bus = new EventBusSrv();
-      const busWithSource = new EventBusWithSource(bus, 'foo');
-      expect(busWithSource.source).toEqual('foo');
+      const busWithSource = bus.newScopedBus('foo');
+      expect((busWithSource as any).path).toEqual(['foo']);
     });
 
     it('adds the source to the event payload', () => {
@@ -60,11 +60,11 @@ describe('EventBus', () => {
 
       bus.subscribe(DataHoverEvent, (event) => events.push(event));
 
-      const busWithSource = new EventBusWithSource(bus, 'foo');
+      const busWithSource = bus.newScopedBus('foo');
       busWithSource.publish({ type: DataHoverEvent.type });
 
       expect(events.length).toEqual(1);
-      expect(events[0].payload.source).toEqual('foo');
+      expect(events[0].origin).toEqual(busWithSource);
     });
   });
 

packages/grafana-data/src/events/EventBus.ts

@@ -1,6 +1,6 @@
 import EventEmitter from 'eventemitter3';
 import { Unsubscribable, Observable } from 'rxjs';
-import { PayloadWithSource } from './common';
+import { filter } from 'rxjs/operators';
 import {
   EventBus,
   LegacyEmitter,
@@ -9,7 +9,7 @@ import {
   LegacyEventHandler,
   BusEvent,
   AppEvent,
-  BusEventWithPayload,
+  EventFilterOptions,
 } from './types';
 
 /**
@@ -44,6 +44,10 @@ export class EventBusSrv implements EventBus, LegacyEmitter {
     });
   }
 
+  newScopedBus(key: string, filter?: EventFilterOptions): EventBus {
+    return new ScopedEventBus([key], this, filter);
+  }
+
   /**
    * Legacy functions
    */
@@ -94,40 +98,48 @@ export class EventBusSrv implements EventBus, LegacyEmitter {
 }
 
 /**
- * @alpha
- *
  * Wraps EventBus and adds a source to help with identifying if a subscriber should react to the event or not.
  */
-export class EventBusWithSource implements EventBus {
-  source: string;
-  eventBus: EventBus;
+class ScopedEventBus implements EventBus {
+  // will be mutated by panel runners
+  filterConfig: EventFilterOptions;
 
-  constructor(eventBus: EventBus, source: string) {
-    this.eventBus = eventBus;
-    this.source = source;
+  // The path is not yet exposed, but can be used to indicate nested groups and support faster filtering
+  constructor(public path: string[], private eventBus: EventBus, filter?: EventFilterOptions) {
+    this.filterConfig = filter ?? { onlyLocal: false };
   }
 
   publish<T extends BusEvent>(event: T): void {
-    const decoratedEvent = {
-      ...event,
-      ...{ payload: { ...event.payload, ...{ source: this.source } } },
-    };
-    this.eventBus.publish(decoratedEvent);
+    if (!event.origin) {
+      (event as any).origin = this;
+    }
+    this.eventBus.publish(event);
   }
 
-  subscribe<T extends BusEvent>(eventType: BusEventType<T>, handler: BusEventHandler<T>): Unsubscribable {
-    return this.eventBus.subscribe(eventType, handler);
-  }
+  filter = (event: BusEvent) => {
+    if (this.filterConfig.onlyLocal) {
+      return event.origin === this;
+    }
+    return true;
+  };
 
   getStream<T extends BusEvent>(eventType: BusEventType<T>): Observable<T> {
-    return this.eventBus.getStream(eventType);
+    return this.eventBus.getStream(eventType).pipe(filter(this.filter)) as Observable<T>;
+  }
+
+  // syntax sugar
+  subscribe<T extends BusEvent>(typeFilter: BusEventType<T>, handler: BusEventHandler<T>): Unsubscribable {
+    return this.getStream(typeFilter).subscribe({ next: handler });
   }
 
   removeAllListeners(): void {
     this.eventBus.removeAllListeners();
   }
 
-  isOwnEvent(event: BusEventWithPayload<PayloadWithSource>): boolean {
-    return event.payload.source === this.source;
+  /**
+   * Creates a nested event bus structure
+   */
+  newScopedBus(key: string, filter: EventFilterOptions): EventBus {
+    return new ScopedEventBus([...this.path, key], this, filter);
   }
 }

packages/grafana-data/src/events/common.ts

@@ -2,12 +2,7 @@ import { DataFrame } from '../types';
 import { BusEventWithPayload } from './types';
 
 /** @alpha */
-export interface PayloadWithSource {
-  source?: string; // source from where the event originates
-}
-
-/** @alpha */
-export interface DataHoverPayload extends PayloadWithSource {
+export interface DataHoverPayload {
   raw: any; // Original mouse event (includes pageX etc)
 
   x: Record<string, any>; // { time: 5678 },

packages/grafana-data/src/events/types.ts

@@ -7,6 +7,7 @@ import { Unsubscribable, Observable } from 'rxjs';
 export interface BusEvent {
   readonly type: string;
   readonly payload?: any;
+  readonly origin?: EventBus;
 }
 
 /**
@@ -52,6 +53,14 @@ export interface BusEventHandler<T extends BusEvent> {
   (event: T): void;
 }
 
+/**
+ * @alpha
+ * Main minimal interface
+ */
+export interface EventFilterOptions {
+  onlyLocal: boolean;
+}
+
 /**
  * @alpha
  * Main minimal interface
@@ -62,20 +71,29 @@ export interface EventBus {
    */
   publish<T extends BusEvent>(event: T): void;
 
-  /**
-   * Subscribe to single event
-   */
-  subscribe<T extends BusEvent>(eventType: BusEventType<T>, handler: BusEventHandler<T>): Unsubscribable;
-
   /**
    * Get observable of events
    */
   getStream<T extends BusEvent>(eventType: BusEventType<T>): Observable<T>;
 
+  /**
+   * Subscribe to an event stream
+   *
+   * This function is a wrapper around the `getStream(...)` function
+   */
+  subscribe<T extends BusEvent>(eventType: BusEventType<T>, handler: BusEventHandler<T>): Unsubscribable;
+
   /**
    * Remove all event subscriptions
    */
   removeAllListeners(): void;
+
+  /**
+   * Returns a new bus scoped that knows where it exists in a heiarchy
+   *
+   * @internal -- This is included for internal use only should not be used directly
+   */
+  newScopedBus(key: string, filter: EventFilterOptions): EventBus;
 }
 
 /**

packages/grafana-ui/src/components/PanelChrome/PanelContext.ts

@@ -1,11 +1,14 @@
-import { EventBusWithSource } from '@grafana/data';
+import { EventBusSrv, EventBus } from '@grafana/data';
 import React from 'react';
 
-interface PanelContext {
-  eventBus?: EventBusWithSource;
+/** @alpha */
+export interface PanelContext {
+  eventBus: EventBus;
 }
 
-const PanelContextRoot = React.createContext<PanelContext>({});
+const PanelContextRoot = React.createContext<PanelContext>({
+  eventBus: new EventBusSrv(),
+});
 
 /**
  * @alpha

packages/grafana-ui/src/components/PanelChrome/index.ts

@@ -37,4 +37,4 @@ export {
   ErrorIndicatorProps as PanelChromeErrorIndicatorProps,
 } from './ErrorIndicator';
 
-export { usePanelContext, PanelContextProvider } from './PanelContext';
+export { usePanelContext, PanelContextProvider, PanelContext } from './PanelContext';

packages/grafana-ui/src/components/PieChart/PieChart.tsx

@@ -143,25 +143,17 @@ function useSliceHighlightState() {
   const { eventBus } = usePanelContext();
 
   useEffect(() => {
-    if (!eventBus) {
-      return;
-    }
-
     const setHighlightedSlice = (event: DataHoverEvent) => {
-      if (eventBus.isOwnEvent(event)) {
-        setHighlightedTitle(event.payload.dataId);
-      }
+      setHighlightedTitle(event.payload.dataId);
     };
 
     const resetHighlightedSlice = (event: DataHoverClearEvent) => {
-      if (eventBus.isOwnEvent(event)) {
-        setHighlightedTitle(undefined);
-      }
+      setHighlightedTitle(undefined);
     };
 
     const subs = new Subscription()
-      .add(eventBus.subscribe(DataHoverEvent, setHighlightedSlice))
-      .add(eventBus.subscribe(DataHoverClearEvent, resetHighlightedSlice));
+      .add(eventBus.getStream(DataHoverEvent).subscribe({ next: setHighlightedSlice }))
+      .add(eventBus.getStream(DataHoverClearEvent).subscribe({ next: resetHighlightedSlice }));
 
     return () => {
       subs.unsubscribe();

packages/grafana-ui/src/components/index.ts

@@ -95,6 +95,7 @@ export {
   PanelChromeErrorIndicator,
   PanelChromeErrorIndicatorProps,
   PanelContextProvider,
+  PanelContext,
   usePanelContext,
 } from './PanelChrome';
 export { VizLayout, VizLayoutComponentType, VizLayoutLegendProps, VizLayoutProps } from './VizLayout/VizLayout';

public/app/features/dashboard/components/SubMenu/AnnotationPicker.tsx

@@ -18,15 +18,19 @@ export const AnnotationPicker = ({ annotation, events, onEnabledChanged }: Annot
   const onCancel = () => getDashboardQueryRunner().cancel(annotation);
 
   useEffect(() => {
-    const started = events.subscribe(AnnotationQueryStarted, (event) => {
-      if (event.payload === annotation) {
-        setLoading(true);
-      }
+    const started = events.getStream(AnnotationQueryStarted).subscribe({
+      next: (event) => {
+        if (event.payload === annotation) {
+          setLoading(true);
+        }
+      },
     });
-    const stopped = events.subscribe(AnnotationQueryFinished, (event) => {
-      if (event.payload === annotation) {
-        setLoading(false);
-      }
+    const stopped = events.getStream(AnnotationQueryFinished).subscribe({
+      next: (event) => {
+        if (event.payload === annotation) {
+          setLoading(false);
+        }
+      },
     });
 
     return () => {

public/app/features/dashboard/dashgrid/PanelChrome.tsx

@@ -4,7 +4,7 @@ import classNames from 'classnames';
 import { Subscription } from 'rxjs';
 // Components
 import { PanelHeader } from './PanelHeader/PanelHeader';
-import { ErrorBoundary, PanelContextProvider } from '@grafana/ui';
+import { ErrorBoundary, PanelContextProvider, PanelContext } from '@grafana/ui';
 // Utils & Services
 import { getTimeSrv, TimeSrv } from '../services/TimeSrv';
 import { applyPanelTimeOverrides } from 'app/features/dashboard/utils/panel';
@@ -15,7 +15,8 @@ import { DashboardModel, PanelModel } from '../state';
 import { PANEL_BORDER } from 'app/core/constants';
 import {
   AbsoluteTimeRange,
-  EventBusWithSource,
+  EventBusSrv,
+  EventFilterOptions,
   FieldConfigSource,
   getDefaultTimeRange,
   LoadingState,
@@ -47,22 +48,34 @@ export interface State {
   renderCounter: number;
   errorMessage?: string;
   refreshWhenInView: boolean;
-  eventBus: EventBusWithSource;
+  context: PanelContext;
   data: PanelData;
 }
 
 export class PanelChrome extends Component<Props, State> {
   private readonly timeSrv: TimeSrv = getTimeSrv();
   private subs = new Subscription();
+  private eventFilter: EventFilterOptions = { onlyLocal: true };
 
   constructor(props: Props) {
     super(props);
 
+    // Can this eventBus be on PanelModel?
+    // when we have more complex event filtering, that may be a better option
+    const eventBus = props.dashboard.events
+      ? props.dashboard.events.newScopedBus(
+          `panel:${props.panel.id}`, // panelID
+          this.eventFilter
+        )
+      : new EventBusSrv();
+
     this.state = {
       isFirstLoad: true,
       renderCounter: 0,
       refreshWhenInView: false,
-      eventBus: new EventBusWithSource(props.dashboard.events, `panel-${props.panel.id}`),
+      context: {
+        eventBus,
+      },
       data: this.getInitialPanelDataState(),
     };
   }
@@ -297,10 +310,14 @@ export class PanelChrome extends Component<Props, State> {
     });
     const panelOptions = panel.getOptions();
 
+    // Update the event filter (dashboard settings may have changed)
+    // Yes this is called ever render for a function that is triggered on every mouse move
+    this.eventFilter.onlyLocal = dashboard.graphTooltip === 0;
+
     return (
       <>
         <div className={panelContentClassNames}>
-          <PanelContextProvider value={{ eventBus: this.state.eventBus }}>
+          <PanelContextProvider value={this.state.context}>
             <PanelComponent
               id={panel.id}
               data={data}

public/app/features/dashboard/state/PanelModel.ts

@@ -11,7 +11,6 @@ import {
   DataLinkBuiltInVars,
   DataQuery,
   DataTransformerConfig,
-  EventBus,
   EventBusSrv,
   FieldConfigSource,
   PanelPlugin,
@@ -170,13 +169,18 @@ export class PanelModel implements DataConfigSource {
   isInView = false;
   configRev = 0; // increments when configs change
   hasRefreshed?: boolean;
-  events: EventBus;
   cacheTimeout?: any;
   cachedPluginOptions: Record<string, PanelOptionsCache> = {};
   legend?: { show: boolean; sort?: string; sortDesc?: boolean };
   plugin?: PanelPlugin;
   dataSupport?: PanelPluginDataSupport;
 
+  /**
+   * The PanelModel event bus only used for internal and legacy angular support.
+   * The EventBus passed to panels is based on the dashboard event model.
+   */
+  events: EventBusSrv;
+
   private queryRunner?: PanelQueryRunner;
 
   constructor(model: any) {

public/app/plugins/panel/annolist/AnnoListPanel.test.tsx

@@ -55,10 +55,11 @@ async function setupTestContext({
   const props: Props = {
     data: { state: LoadingState.Done, timeRange: getDefaultTimeRange(), series: [] },
     eventBus: {
+      subscribe: jest.fn(),
       getStream: jest.fn(),
       publish: jest.fn(),
       removeAllListeners: jest.fn(),
-      subscribe: jest.fn(),
+      newScopedBus: jest.fn(),
     },
     fieldConfig: ({} as unknown) as FieldConfigSource,
     height: 400,

public/app/plugins/panel/debug/EventBusLogger.tsx

@@ -3,12 +3,10 @@ import { CustomScrollbar } from '@grafana/ui';
 import {
   BusEvent,
   CircularVector,
-  DataHoverPayload,
   DataHoverEvent,
   DataHoverClearEvent,
   DataSelectEvent,
   EventBus,
-  BusEventHandler,
 } from '@grafana/data';
 import { PartialObserver, Unsubscribable } from 'rxjs';
 
@@ -24,22 +22,25 @@ interface State {
 interface BusEventEx {
   key: number;
   type: string;
-  payload: DataHoverPayload;
+  path: string;
+  payload: any;
 }
 let counter = 100;
 
 export class EventBusLoggerPanel extends PureComponent<Props, State> {
   history = new CircularVector<BusEventEx>({ capacity: 40, append: 'head' });
-  subs: Unsubscribable[] = [];
+  subs: Unsubscribable[];
 
   constructor(props: Props) {
     super(props);
 
     this.state = { counter };
 
-    this.subs.push(props.eventBus.subscribe(DataHoverEvent, this.hoverHandler));
-    props.eventBus.getStream(DataHoverClearEvent).subscribe(this.eventObserver);
-    props.eventBus.getStream(DataSelectEvent).subscribe(this.eventObserver);
+    const subs: Unsubscribable[] = [];
+    subs.push(props.eventBus.getStream(DataHoverEvent).subscribe(this.eventObserver));
+    subs.push(props.eventBus.getStream(DataHoverClearEvent).subscribe(this.eventObserver));
+    subs.push(props.eventBus.getStream(DataSelectEvent).subscribe(this.eventObserver));
+    this.subs = subs;
   }
 
   componentWillUnmount() {
@@ -48,17 +49,17 @@ export class EventBusLoggerPanel extends PureComponent<Props, State> {
     }
   }
 
-  hoverHandler: BusEventHandler<DataHoverEvent> = (event: DataHoverEvent) => {
-    this.history.add({
-      key: counter++,
-      type: event.type,
-      payload: event.payload,
-    });
-    this.setState({ counter });
-  };
-
   eventObserver: PartialObserver<BusEvent> = {
-    next: (v: BusEvent) => {},
+    next: (event: BusEvent) => {
+      const origin = event.origin as any;
+      this.history.add({
+        key: counter++,
+        type: event.type,
+        path: origin?.path,
+        payload: event.payload,
+      });
+      this.setState({ counter });
+    },
   };
 
   render() {
@@ -66,7 +67,7 @@ export class EventBusLoggerPanel extends PureComponent<Props, State> {
       <CustomScrollbar autoHeightMin="100%" autoHeightMax="100%">
         {this.history.map((v, idx) => (
           <div key={v.key}>
-            {v.key} {v.type} / X:{JSON.stringify(v.payload.x)} / Y:{JSON.stringify(v.payload.y)}
+            {JSON.stringify(v.path)} {v.type} / X:{JSON.stringify(v.payload.x)} / Y:{JSON.stringify(v.payload.y)}
           </div>
         ))}
       </CustomScrollbar>