Basic-rxjs-epic.js

export function getData(action$) {
  return action$.ofType(GET_DATA) // action type for epic to listen changes
    .switchMap(data => { // switchMap is used to always get latest stream ( i.e switch to new stream )
        return Observable.ajax(getData(data.id)) //some id 
        .flatMap(results => { // flatmap is used to flatten the inner observables 
          return Observable.of(
            getDataSuccess(results) // success action 
          )
        })
        .catch((error, source) => {
          return Observable.of(getDataFailure(error)) // failure action 
        })
    })
}