104 lines
2.7 KiB
Markdown
104 lines
2.7 KiB
Markdown
---
|
|
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>
|