How do you access query arguments in getSelectors() when using createEntityAdapter with RTK Query

Question

I've been following along the REDUX essentials guide and I'm at part 8, combining RTK Query with the createEntityAdapter. I'm using the guide to implement it in a personal project where my getUni endpoint has an argument named country, as you can see from the code snippet below.

I'm wondering is there anyway to access the country argument value from the state in universityAdaptor.getSelector(state => ) at the bottom of the snippet, as the query key name keeps changing.

import {
  createEntityAdapter,
  createSelector,
  nanoid
} from "@reduxjs/toolkit";
import {
  apiSlice
} from "../api/apiSlice";


const universityAdapter = createEntityAdapter({})

const initialState = universityAdapter.getInitialState();

export const extendedApiSlice = apiSlice.injectEndpoints({
  endpoints: builder => ({
    getUni: builder.query({
      query: country => ({
        url: `http://universities.hipolabs.com/search?country=${country}`,
      }),
      transformResponse: responseData => {
        let resConvert = responseData.slice()
          .sort((a, b) => a.name.localeCompare(b.name))
          .map(each => {
            return { ...each,
              id: nanoid()
            }
          });

        return universityAdapter.setAll(initialState, resConvert)
      }
    })
  })
});

export const {
  useGetUniQuery
} = extendedApiSlice;


export const {
  selectAll: getAllUniversity
} = universityAdapter.getSelectors(state => {
  return Object.keys({ ...state.api.queries[<DYNAMIC_QUERY_NAME>]data }).length === 0  
? initialState : { ...state.api.queries[<DYNAMIC_QUERY_NAME>]data }
})

UPDATE: I got it working with a turnery operator due to the multiple redux Actions created when RTK Query handles fetching. Wondering if this is best practice as I still haven't figured out how to access the country argument.

export const { selectAll: getAllUniversity } = universityAdapter
  .getSelectors(state => {

  return !Object.values(state.api.queries)[0]
    ? initialState : Object.values(state.api.queries)[0].status !== 'fulfilled'
      ? initialState : Object.values(state.api.queries)[0].data
})

Answer 1

I wrote that "Essentials" tutorial :)

I'm actually a bit confused what your question is - can you clarify what specifically you're trying to do?

That said, I'll try to offer some hopefully relevant info.

First, you don't need to manually call someEndpoint.select() most of the time - instead, call const { data } = useGetThingQuery("someArg"), and RTKQ will fetch and return it. You only need to call someEndpoint.select() if you're manually constructing a selector for use elsewhere.

Second, if you are manually trying to construct a selector, keep in mind that the point of someEndpoint.select() is to construct "a selector that gives you back the entire cache entry for that cache key". What you usually want from that cache entry is just the received value, which is stored as cacheEntry.data, and in this case that will contain the normalized { ids : [], entities: {} } lookup table you returned from transformResponse().

Notionally, you might be able to do something like this:

const selectNormalizedPokemonData = someApi.endpoints.getAllPokemon.select();

// These selectors expect the entity state as an arg, 
// not the entire Redux root state: 
// https://redux-toolkit.js.org/api/createEntityAdapter#selector-functions
const localizedPokemonSelectors = pokemonAdapter.getSelectors();

const selectPokemonEntryById = createSelector(
  selectNormalizedPokemonData ,
  (state, pokemonId) => pokemonId,
  (pokemonData, pokemonId) => {
    return localizedPokemonSelectors.selectById(pokemonData, pokemonId);
  }
)