recharts/src/state/RechartsStoreProvider.tsx

import * as React from 'react';
import { Context, MutableRefObject, ReactNode, useRef } from 'react';
import { Provider } from 'react-redux';
import { Action, Store } from '@reduxjs/toolkit';
import { createRechartsStore, RechartsRootState } from './store';
import { useIsPanorama } from '../context/PanoramaContext';
import { RechartsReduxContext, RechartsReduxContextValue } from './RechartsReduxContext';

type RechartsStoreProviderProps = {
  children: ReactNode;
  preloadedState?: Partial<RechartsRootState>;
  reduxStoreName?: string;
};

export function RechartsStoreProvider({ preloadedState, children, reduxStoreName }: RechartsStoreProviderProps) {
  const isPanorama = useIsPanorama();
  /*
   * Why the ref? Redux official documentation recommends to use store as a singleton,
   * and reuse that everywhere: https://redux-toolkit.js.org/api/configureStore#basic-example
   *
   * Which is correct! Except that is considering deploying Redux in an app.
   * Recharts as a library supports multiple charts on the same page.
   * And each of these charts needs its own store independent of others!
   *
   * The alternative is to have everything in the store keyed by the chart id.
   * Which would make working with everything a little bit more painful because we need the chart id everywhere.
   */
  const storeRef: MutableRefObject<Store<RechartsRootState, Action> | null> = useRef(null);

  /*
   * Panorama means that this chart is not its own chart, it's only a "preview"
   * being rendered as a child of Brush.
   * In such case, it should not have a store on its own - it should implicitly inherit
   * whatever data is in the "parent" or "root" chart.
   * Which here is represented by not having a Provider at all. All selectors will use the root store by default.
   */
  if (isPanorama) {
    return children;
  }

  if (storeRef.current == null) {
    storeRef.current = createRechartsStore(preloadedState, reduxStoreName);
  }

  // ts-expect-error React-Redux types demand that the context internal value is not null, but we have that as default.
  const nonNullContext: Context<RechartsReduxContextValue> = RechartsReduxContext;

  return (
    <Provider context={nonNullContext} store={storeRef.current}>
      {children}
    </Provider>
  );
}