grafana/public/app/plugins/datasource/dashboard/runSharedRequest.ts

import { Observable } from 'rxjs';

import {
  DataQuery,
  DataQueryRequest,
  DataSourceApi,
  DataSourceRef,
  getDefaultTimeRange,
  LoadingState,
  PanelData,
  DataTopic,
} from '@grafana/data';
import { getDashboardSrv } from 'app/features/dashboard/services/DashboardSrv';
import { PanelModel } from 'app/features/dashboard/state/PanelModel';
import { QueryRunnerOptions } from 'app/features/query/state/PanelQueryRunner';

import { SHARED_DASHBOARD_QUERY } from './constants';
import { DashboardQuery } from './types';

export function isSharedDashboardQuery(datasource: string | DataSourceRef | DataSourceApi | null) {
  if (!datasource) {
    // default datasource
    return false;
  }

  if (typeof datasource === 'string') {
    return datasource === SHARED_DASHBOARD_QUERY;
  }

  if ('meta' in datasource) {
    return datasource.meta.name === SHARED_DASHBOARD_QUERY || datasource.uid === SHARED_DASHBOARD_QUERY;
  }

  return datasource.uid === SHARED_DASHBOARD_QUERY;
}

export function runSharedRequest(options: QueryRunnerOptions, query: DashboardQuery): Observable<PanelData> {
  return new Observable<PanelData>((subscriber) => {
    const dashboard = getDashboardSrv().getCurrent();
    const listenToPanelId = getPanelIdFromQuery(options.queries);

    if (!listenToPanelId) {
      subscriber.next(getQueryError('Missing panel reference ID'));
      return undefined;
    }

    // Source panel might be contained in a collapsed row, in which
    // case we need to create a PanelModel
    let listenToPanel = dashboard?.getPanelById(listenToPanelId, true);
    if (!(listenToPanel instanceof PanelModel)) {
      listenToPanel = new PanelModel(listenToPanel);
    }

    if (!listenToPanel) {
      subscriber.next(getQueryError('Unknown Panel: ' + listenToPanelId));
      return undefined;
    }

    const listenToRunner = listenToPanel.getQueryRunner();
    const subscription = listenToRunner
      .getData({
        withTransforms: Boolean(query?.withTransforms),
        withFieldConfig: false,
      })
      .subscribe({
        next: (data: PanelData) => {
          // Use annotation data for series
          if (query?.topic === DataTopic.Annotations) {
            data = {
              ...data,
              series: data.annotations ?? [],
              annotations: undefined, // remove annotations
            };
          }
          subscriber.next(data);
        },
      });

    // If we are in fullscreen the other panel will not execute any queries
    // So we have to trigger it from here
    if (
      (!listenToPanel.isInView && listenToPanel.refreshWhenInView) ||
      dashboard?.otherPanelInFullscreen(listenToPanel)
    ) {
      const { datasource, targets } = listenToPanel;
      const modified = {
        ...options,
        datasource,
        panelId: listenToPanelId,
        queries: targets,
      };

      listenToPanel.refreshWhenInView = false;
      listenToRunner.run(modified);
    }

    return () => {
      subscription.unsubscribe();
    };
  });
}

function getPanelIdFromQuery(queries: DataQuery[]): number | undefined {
  if (!queries || !queries.length) {
    return undefined;
  }
  return (queries[0] as DashboardQuery).panelId;
}

function getQueryError(msg: string): PanelData {
  return {
    state: LoadingState.Error,
    series: [],
    request: {} as DataQueryRequest,
    error: { message: msg },
    timeRange: getDefaultTimeRange(),
  };
}