freeCodeCamp/curriculum/challenges/arabic/03-front-end-libraries/redux/use-middleware-to-handle-as...

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---
id: 5a24c314108439a4d4036156
title: Use Middleware to Handle Asynchronous Actions
challengeType: 6
isRequired: false
videoUrl: ''
localeTitle: ''
---
## Description
undefined
## Instructions
undefined
## Tests
<section id='tests'>
```yml
tests:
- text: ''
testString: 'assert(requestingData().type === REQUESTING_DATA, "The <code>requestingData</code> action creator should return an object of type equal to the value of <code>REQUESTING_DATA</code>.");'
- text: ''
testString: 'assert(receivedData("data").type === RECEIVED_DATA, "The <code>receivedData</code> action creator should return an object of type equal to the value of <code>RECEIVED_DATA</code>.");'
- text: ''
testString: 'assert(typeof asyncDataReducer === "function", "<code>asyncDataReducer</code> should be a function.");'
- text: ''
testString: 'assert((function() { const initialState = store.getState(); store.dispatch(requestingData()); const reqState = store.getState(); return initialState.fetching === false && reqState.fetching === true })(), "Dispatching the requestingData action creator should update the store <code>state</code> property of fetching to <code>true</code>.");'
- text: ''
testString: 'assert((function() { const noWhiteSpace = handleAsync.toString().replace(/\s/g,""); return noWhiteSpace.includes("dispatch(requestingData())") === true && noWhiteSpace.includes("dispatch(receivedData(data))") === true })(), "Dispatching <code>handleAsync</code> should dispatch the data request action and then dispatch the received data action after a delay.");'
```
</section>
## Challenge Seed
<section id='challengeSeed'>
<div id='jsx-seed'>
```jsx
const REQUESTING_DATA = 'REQUESTING_DATA'
const RECEIVED_DATA = 'RECEIVED_DATA'
const requestingData = () => { return {type: REQUESTING_DATA} }
const receivedData = (data) => { return {type: RECEIVED_DATA, users: data.users} }
const handleAsync = () => {
return function(dispatch) {
// dispatch request action here
setTimeout(function() {
let data = {
users: ['Jeff', 'William', 'Alice']
}
// dispatch received data action here
}, 2500);
}
};
const defaultState = {
fetching: false,
users: []
};
const asyncDataReducer = (state = defaultState, action) => {
switch(action.type) {
case REQUESTING_DATA:
return {
fetching: true,
users: []
}
case RECEIVED_DATA:
return {
fetching: false,
users: action.users
}
default:
return state;
}
};
const store = Redux.createStore(
asyncDataReducer,
Redux.applyMiddleware(ReduxThunk.default)
);
```
</div>
</section>
## Solution
<section id='solution'>
```js
// solution required
```
</section>