在catchError内发出多个动作- Redux可观察

import { catchError } from 'rxjs/operators';
import { of } from 'rxjs';
import { ajax } from 'rxjs/ajax';

// 定义一个异步操作的Action
const fetchData = () => {
  return dispatch => {
    dispatch({ type: 'FETCH_DATA_START' });

    ajax.getJSON('https://api.example.com/data')
      .pipe(
        catchError(error => {
          // 在catchError内发出多个动作
          dispatch({ type: 'FETCH_DATA_ERROR', payload: error });
          dispatch({ type: 'SHOW_ERROR_MESSAGE', payload: 'Failed to fetch data' });

          // 返回一个空的Observable，以避免中断整个流程
          return of(null);
        })
      )
      .subscribe(response => {
        if (response) {
          dispatch({ type: 'FETCH_DATA_SUCCESS', payload: response });
        }
      });
  };
};