PS - This was originally posted in my blog. Check it out if you want learn more about React and JavaScript!
PPS - I got to know about hooks in Redux thanks to Antoine in my previous post.
In my previous post I went through setting up Redux in a React app. Since then I learnt about using hooks as an alternative to the connect()
Higher Order Component. In this post we will refactor the app we made in the previous post to use the Redux Hooks.
Getting Started
Before we start refactoring let's check out the two hooks we are going to use.
-
useSelector
- Allows us to get the state from the Redux store. This hook will be used to replacemapStateToProps
inconnect()
. -
useDispatch
- Allows us to dispatch out redux actions. This hook will be used to replacemapDispatchToProps
inconnect()
.
Refactoring the Controls Component
First lets remove the props, connect()
Higher Order Component and mapStateToProps
and mapDispatchToProps
.
const Controls = () => {
return (
<div>
<button
onClick={() => actions.setUserId(user.userId - 1)}
disabled={user.userId <= 1 || user.isFetchingUser}
>
Previous
</button>
<button
onClick={() => actions.setUserId(user.userId + 1)}
disabled={user.userId >= 10 || user.isFetchingUser}
>
Next
</button>
</div>
)
}
export default Controls
Then we need to import the two hooks from react-redux.
import { useSelector, useDispatch } from "react-redux"
To get the redux state, we need to use useSelector
. useSelector
needs a function as an argument where the redux state is the parameter and the return object is the state we need, similar to mapStateToProps
. So use useSelector
to declare the user inside the component.
const user = useSelector(state => ({ user: state.user }))
The above line of code can be shortened to the following.
const user = useSelector(state => state.user)
To call the redux actions, we need to declare the dispatch function in the component using the useDispatch
hook. After that we can call out redux actions inside the dispatch function like we did in the getUser
action.
const dispatch = useDispatch()
Just change all actions to run inside the dispatch
function like this.
dispatch(setUserId(user.userId - 1))
In the end the Controls component should look like this.
import React from "react"
import { useSelector, useDispatch } from "react-redux"
import { setUserId } from "../redux/user/actions"
const Controls = () => {
const user = useSelector(state => state.user)
const dispatch = useDispatch()
return (
<div>
<button
onClick={() => dispatch(setUserId(user.userId - 1))}
disabled={user.userId <= 1 || user.isFetchingUser}
>
Previous
</button>
<button
onClick={() => dispatch(setUserId(user.userId + 1))}
disabled={user.userId >= 10 || user.isFetchingUser}
>
Next
</button>
</div>
)
}
export default Controls
Refactoring the Display Component
We need to refactor the Display component the same way we did the Controls component.
- Remove all the
connect()
Higher Order Component related code. - Import
useSelector
anduseDispatch
.
import { useSelector, useDispatch } from "react-redux"
- Declare the user state using
useSelector
.
const user = useSelector(state => state.user)
- Declare the dispatch function using
useDispatch
.
const dispatch = useDispatch()
- Change all Redux action to be called inside the
dispatch
function.
dispatch(getUser(user.userId))
In the end the code for the Display component should look like this.
import React from "react"
import { useSelector, useDispatch } from "react-redux"
import { getUser } from "../redux/user/actions"
const Display = () => {
const user = useSelector(state => state.user)
const dispatch = useDispatch()
React.useEffect(() => {
dispatch(getUser(user.userId))
}, [user.userId])
return (
<div>
<table>
<tbody>
<tr>
<td>ID: </td>
<td>{user.user.id}</td>
</tr>
<tr>
<td>Name: </td>
<td>{user.user.name}</td>
</tr>
<tr>
<td>Username: </td>
<td>{user.user.username}</td>
</tr>
<tr>
<td>Email: </td>
<td>{user.user.email}</td>
</tr>
</tbody>
</table>
</div>
)
}
export default Display
Wrap Up
This is a sample of the setup we just did. If you think you missed something, feel free to check out the code.
If you want to learn more about the hooks in react-redux, please check out the official documentation here.
If you found this post helpful please make sure to share it! 😊
Top comments (1)
Nice post, helped me to figure out on how to structure and use redux with hooks.