reducer.state.props is undefined in nested actions react/redux - redux

Question

Below are my action and reducer files - In my component state I am only seeing this.props.mainData - but others subdataOneData etc., are not being loaded in to the state - till reducer i see the right actions are being dispatched and I also see the data for sub - calls - but they are not reaching my component - I have mapStatetoprops - where I am doing
New issue: as per the updated code - when i print out payload in reducer - I see maindata with the api data but SubData [{}, {}, {}] ..?
Updated code:
import { GET_DATA_AND_SUBDATA } from '../constants/types';
export function getMainData() {
return async function getMainData(dispatch) {
const { data } = await getMainDataAPI();
const subData = data.map((item) => {
const endpoint = 'build with item.name';
return Request.get(endpoint);
});
console.log('subddd' + subData); prints -> **[object Promise],[object Promise],[object Promise]**
dispatch({
type: GET_DATA_AND_SUBDATA,
payload: { data, subData }
});
};
}
async function getMainDataAPI() {
const endpoint = 'url';
return Request.get(endpoint);
}

Answer 1

The problem lies on the way you dispatch the actions.
You are not providing data for mainData and subdataOneData at the same time.
export function getData() {
return async function getData(dispatch) {
const { data } = await getDataAPI();
// This will cause first re-render
dispatch({ type: GET_DATA, payload: data });
Object.keys(data).map((keyName, keyIndex) => {
const endpoint = 'ENDPOINT';
Request.get(endpoint).then((response) => {
// This will cause second re-render
dispatch({
type: GET_subdata + keyIndex,
payload: response.data });
});
return keyIndex;
});
};
}
At first render your subdataOneData is not availble yet.
You are not even specifying a default value in the reducer, therefore it will be undefined.
You can change your action thunk like this
export function getData() {
return async function getData(dispatch) {
const { data } = await getDataAPI();
const subDataResponse = await Promise.all(
Object.keys(data).map( () => {
const endpoint = 'ENDPOINT';
return Request.get(endpoint)
})
)
const subData = subDataResponse.map( response => response.data )
dispatch({
type: GET_DATA_AND_SUBDATA
payload: { data, subData }
});
};
}
And change your reducer accordingly in order to set all data at once.
export default function myReducer(state = {}, action) {
switch (action.type) {
case GET_DATA_AND_SUBDATA:
return {
...state,
mainData: action.payload.data,
subdataOneData: action.payload.subData[0],
subdataTwoData: action.payload.subData[1]
};
default:
return state;
}
}
Note: it's also a good practice to set your initial state in the reducer.
const initialState = {
mainData: // SET YOUR INITIAL DATA
subdataOneData: // SET YOUR INITIAL DATA
subdataTwoData: // SET YOUR INITIAL DATA
}
export default function myReducer(initialState, action) {