Access to the latest state from redux-observable epic after api response - redux

Question

I have read this Accessing the state from within a redux-observable epic, but it doesn't helps me finding the answer.
I am using redux-observable in my react-redux app, I have an epic will trigger an API invoke, code as below:
const streamEpicGet = (action$: Observable<Action>, state$) => action$
.pipe(
ofType(streamActions.STREAM_ITEM_GET),
withLatestFrom(state$),
mergeMap(([action, state]) => {
return observableRequest(
{
failureObservable: error => {
const actions = []
return actions
},
settings: {
body: queryParams, // I can access to the state data here to organize the query params I need for calling the API
url: '/path/to/api',
},
successObservable: result => {
const { pushQueue } = state
// here I want to access to the latest state data after API response
}
})
}),
)
In the above code, I use withLatestFrom(state$) so I can access to the latest data when executing the mergeMap operator code, that is to say I can access to the state data here to organize the query params for API.
However, during the time after API request sends out and before it responses, there are other actions happening, which are changing the state's pushQueue, so after the API response, I want to read the latest state pushQueue in my successObservable callback.
My problem is I always get the same state data as when preparing the query param, i.e.: I cannot get the latest state data after API response in successObservable callback.
Let me know if you need more info, thanks.

Answer 1

const streamEpicGet = (action$: Observable<Action>, state$) => action$
.pipe(
ofType(streamActions.STREAM_ITEM_GET),
withLatestFrom(state$),
mergeMap(([action, state]) => {
return observableRequest(
{
failureObservable: error => {
const actions = []
return actions
},
settings: {
body: queryParams, // I can access to the state data here to organize the query params I need for calling the API
url: '/path/to/api',
},
successObservable: result => {
const { pushQueue } = state$.value // Use state$.value to always access to the latest state
// here I want to access to the latest state data after API response
}
})
}),
)
So the answer is to use state$.value.
I get this by reading Accessing state in redux-observable Migration document