Using Middleware for Async Type Adaptation

Show how to integrate middleware like redux-thunk or redux-saga to handle type changes asynchronously when a user action requires a multi-stage update to the Redux state.

import { createStore, applyMiddleware } from 'redux';
import thunk from 'redux-thunk';
import rootReducer from './reducers';

// Create Redux store with thunk middleware
const store = createStore(
  rootReducer,
  applyMiddleware(thunk)
);

This code creates a Redux store and applies the redux-thunk middleware. The thunk middleware allows for writing action creators that return a function instead of an action object, which can then be used to dispatch asynchronous operations.

import { useDispatch } from 'react-redux';

// Action Types
const UPDATE_REQUEST = 'UPDATE_REQUEST';
const UPDATE_SUCCESS = 'UPDATE_SUCCESS';
const UPDATE_FAILURE = 'UPDATE_FAILURE';

// Action Creators with async operation
const updateDataAsync = (newType) => {
  return (dispatch) => {
    dispatch({ type: UPDATE_REQUEST });
    // Simulate async API call
    setTimeout(() => {
      try {
        // Perform type adaptation here e.g. changing data type
        const adaptedType = adaptType(newType);
        dispatch({ type: UPDATE_SUCCESS, payload: adaptedType });
      } catch (error) {
        dispatch({ type: UPDATE_FAILURE, error });
      }
    }, 1000);
  };
};

function adaptType(type) {
  // Logic to adapt the type
  return type;
}

// Usage of the action creator in a component
const SomeComponent = () => {
  const dispatch = useDispatch();

  const handleTypeChange = (newType) => {
    dispatch(updateDataAsync(newType));
  };

  // Component code continues...
}

This snippet includes action types for an async update process, an async action creator using redux-thunk that simulates an API call with a setTimeout, and a useDispatch hook usage example within a component function to dispatch the async update based on a new type. The adaptType function is a stub for actual data type adaptation logic.

import { all, call, put, takeEvery } from 'redux-saga/effects';

// Action Types
const UPDATE_REQUEST = 'UPDATE_REQUEST';
const UPDATE_SUCCESS = 'UPDATE_SUCCESS';
const UPDATE_FAILURE = 'UPDATE_FAILURE';

// Worker Saga
function* updateDataSaga(action) {
  try {
    // Call your type adaptation logic or API call here
    const adaptedType = yield call(adaptType, action.payload);
    yield put({ type: UPDATE_SUCCESS, payload: adaptedType });
  } catch (error) {
    yield put({ type: UPDATE_FAILURE, error });
  }
}

// Watcher Saga
function* watchUpdateRequest() {
  yield takeEvery(UPDATE_REQUEST, updateDataSaga);
}

// Root Saga
export default function* rootSaga() {
  yield all([
    watchUpdateRequest(),
  ]);
}

function adaptType(type) {
  // Logic to adapt the type
  return type;
}

This code snippet demonstrates how to set up a watcher and worker saga using redux-saga to handle asynchronous type adaptation. 'updateDataSaga' is the worker saga that will perform the async task, and 'watchUpdateRequest' is the watcher saga that listens for the UPDATE_REQUEST action type to invoke the worker saga. The adaptType function is a placeholder for the type adaptation logic.