I want to show some records in a table using React but I got this error:
Invalid hook call. Hooks can only be called inside of the body of a function component. This could happen for one of the following reasons: You might have mismatching versions of React and the renderer (such as React DOM) You might be breaking the Rules of Hooks You might have more than one copy of React in the same app See for tips about how to debug and fix this problem.
import React, {
Component
} from 'react';
import {
makeStyles
} from '@material-ui/core/styles';
import Table from '@material-ui/core/Table';
import TableBody from '@material-ui/core/TableBody';
import TableCell from '@material-ui/core/TableCell';
import TableHead from '@material-ui/core/TableHead';
import TableRow from '@material-ui/core/TableRow';
import Paper from '@material-ui/core/Paper';
const useStyles = makeStyles(theme => ({
root: {
width: '100%',
marginTop: theme.spacing(3),
overflowX: 'auto',
},
table: {
minWidth: 650,
},
}));
class allowance extends Component {
constructor() {
super();
this.state = {
allowances: [],
};
}
componentWillMount() {
fetch('http://127.0.0.1:8000/allowances')
.then(data => {
return data.json();
}).then(data => {
this.setState({
allowances: data
});
console.log("allowance state", this.state.allowances);
})
}
render() {
const classes = useStyles();
return ( <
Paper className = {
classes.root
} >
<
Table className = {
classes.table
} >
<
TableHead >
<
TableRow >
<
TableCell > Allow ID < /TableCell> <
TableCell align = "right" > Description < /TableCell> <
TableCell align = "right" > Allow Amount < /TableCell> <
TableCell align = "right" > AllowType < /TableCell>
<
/TableRow> <
/TableHead> <
TableBody > {
this.state.allowances.map(row => ( <
TableRow key = {
row.id
} >
<
TableCell component = "th"
scope = "row" > {
row.AllowID
} <
/TableCell> <
TableCell align = "right" > {
row.AllowDesc
} < /TableCell> <
TableCell align = "right" > {
row.AllowAmt
} < /TableCell> <
TableCell align = "right" > {
row.AllowType
} < /TableCell> <
/TableRow>
))
} <
/TableBody> <
/Table> <
/Paper>
);
}
}
export default allowance;
I had this issue when I used npm link
to install my local library, which I've built using cra
. I found the answer here. Which literally says:
This problem can also come up when you use npm link or an equivalent. In that case, your bundler might “see” two Reacts — one in application folder and one in your library folder. Assuming 'myapp' and 'mylib' are sibling folders, one possible fix is to run 'npm link ../myapp/node_modules/react' from 'mylib'. This should make the library use the application’s React copy.
Thus, running the command: npm link <path_to_local_library>/node_modules/react
, eg. in my case npm link ../../libraries/core/decipher/node_modules/react
from the project directory has fixed the issue.
You can only call hooks from React functions. Read more here.
Just convert the Allowance
class component to a functional component.
const Allowance = () => {
const [allowances, setAllowances] = useState([]);
useEffect(() => {
fetch("http://127.0.0.1:8000/allowances")
.then(data => {
return data.json();
})
.then(data => {
setAllowances(data);
})
.catch(err => {
console.log(123123);
});
}, []);
const classes = useStyles();
return ( <
Paper className = {
classes.root
} >
<
Table className = {
classes.table
} >
<
TableHead >
<
TableRow >
<
TableCell > Allow ID < /TableCell> <
TableCell align = "right" > Description < /TableCell> <
TableCell align = "right" > Allow Amount < /TableCell> <
TableCell align = "right" > AllowType < /TableCell> <
/TableRow> <
/TableHead> <
TableBody > {
allowances.map(row => ( <
TableRow key = {
row.id
} >
<
TableCell component = "th"
scope = "row" > {
row.AllowID
} <
/TableCell> <
TableCell align = "right" > {
row.AllowDesc
} < /TableCell> <
TableCell align = "right" > {
row.AllowAmt
} < /TableCell> <
TableCell align = "right" > {
row.AllowType
} < /TableCell> <
/TableRow>
))
} <
/TableBody> <
/Table> <
/Paper>
);
};
export default Allowance;
setAllowances
working like this.setState({allowances: data})
setAllowances
is async like this.setState. so you log allowances
after setAllowances
it will log the old allowances
.
You can use "export default" by calling an Arrow Function that returns its React.Component by passing it through the MaterialUI class object props, which in turn will be used within the Component render ().
class AllowanceClass extends Component{
...
render() {
const classes = this.props.classes;
...
}
}
export default () => {
const classes = useStyles();
return (
<AllowanceClass classes={classes} />
)
}
React linter assumes every method starting with use
as hooks and hooks doesn't work inside classes. by renaming const useStyles
into anything else that doesn't starts with use
like const myStyles
you are good to go.
Update:
makeStyles
is hook api and you can't use that inside classes. you can use styled components API. see here
For me , the error was calling the function useState outside the function default exported
Yesterday, I shortened the code (just added <Provider store={store}>
) and still got this invalid hook call problem. This made me suddenly realized what mistake I did: I didn't install the react-redux software in that folder.
I had installed this software in the other project folder, so I didn't realize this one also needed it. After installing it, the error is gone.
This error can also occur when you make the mistake of declaring useDispatch from react-redux the wrong way: when you go:
const dispatch = useDispatch
instead of:
const dispatch = useDispatch();
(i.e remember to add the parenthesis)
redux
react-redux
packages not installed at project level(but present at top level in a monorepo).
complementing the following comment
For those who use redux:
class AllowanceClass extends Component{
...
render() {
const classes = this.props.classes;
...
}
}
const COMAllowanceClass = (props) =>
{
const classes = useStyles();
return (<AllowanceClass classes={classes} {...props} />);
};
const mapStateToProps = ({ InfoReducer }) => ({
token: InfoReducer.token,
user: InfoReducer.user,
error: InfoReducer.error
});
export default connect(mapStateToProps, { actions })(COMAllowanceClass);
Different versions of react between my shared libraries seemed to be the problem (16 and 17), changed both to 16.
add this to your package.json
"peerDependencies": {
"react": ">=16.8.0",
"react-dom": ">=16.8.0"
}
source:https://robkendal.co.uk/blog/2019-12-22-solving-react-hooks-invalid-hook-call-warning
You can convert class component to hooks,but Material v4 has a withStyles HOC. https://material-ui.com/styles/basics/#higher-order-component-api Using this HOC you can keep your code unchanged.
I have just started using hooks and I got the above warning when i was calling useEffect inside a function:
Then I have to move the useEffect outside of the function as belows:
const onChangeRetypePassword = async value => {
await setRePassword(value);
//previously useEffect was here
};
//useEffect outside of func
useEffect(() => {
if (password !== rePassword) {
setPasswdMismatch(true);
}
else{
setPasswdMismatch(false);
}
}, [rePassword]);
Hope it will be helpful to someone !
In my case, I was passing Component Name in FlatList
's renderItem
prop instead of function. It was working earlier as my component was a functional component but when I added hooks in it, it failed.
Before:
<FlatList
data={memberList}
renderItem={<MemberItem/>}
keyExtractor={member => member.name.split(' ').join('')}
ListEmptyComponent={
<Text style={{textAlign: 'center', padding: 30}}>
No Data: Click above button to fetch data
</Text>
}
/>
After:
<FlatList
data={memberList}
renderItem={({item, index}) => <MemberItem item={item} key={index} />}
keyExtractor={member => member.name.split(' ').join('')}
ListEmptyComponent={
<Text style={{textAlign: 'center', padding: 30}}>
No Data: Click above button to fetch data
</Text>
}
/>
In my case, it was just this single line of code here which was on my App.js that caused this and made me lose 10 hours in debugging. The React Native and Expo could not point me to this. I did everything that was on StackOverflow and github and even the react page that was supposed to solve this and the issue persisted. I had o start taking my code apart bit by bit to get to the culprit
**const window = useWindowDimensions();**
It was placed like this:
import * as React from 'react';
import { Text, View, StyleSheet, ImageBackground, StatusBar, Image, Alert, SafeAreaView, Button, TouchableOpacity, useWindowDimensions } from 'react-native';
import Constants from 'expo-constants';
import Whooksplashscreen11 from './Page1';
import Screen1 from './LoginPage';
import Loginscreen from './Login';
import RegisterScreen1 from './register1';
import RegisterScreen2 from './register2-verifnum';
import RegisterScreen3 from './register3';
import RegisterScreen4 from './register4';
import RegisterScreen5 from './register5';
import RegisterScreen6 from './register6';
import BouncyCheckbox from "react-native-bouncy-checkbox";
import LocationPermission from './LocationPermission.js'
import Selfieverif1 from './selfieverif1'
import Selfieverif2 from './selfieverif2'
import AddPhotos from './addphotos'
// You can import from local files
import { useFonts } from 'expo-font';
// or any pure javascript modules available in npm
import { NavigationContainer } from '@react-navigation/native';
import { createNativeStackNavigator } from '@react-navigation/native-stack';
//FontAwesome
import { library } from '@fortawesome/fontawesome-svg-core'
import { fab, } from '@fortawesome/free-brands-svg-icons'
import { faCheckSquare, faCoffee, faFilter, faSearch, } from '@fortawesome/free-solid-svg-icons'
import { FontAwesomeIcon } from '@fortawesome/react-native-fontawesome'
import Icon from "react-native-vector-icons/FontAwesome5";
import MyTabs from './swipepage'
library.add(fab, faCheckSquare, faCoffee, faFilter, faSearch,);
const window = useWindowDimensions();
const Stack = createNativeStackNavigator();
function App() {
return ( ....
)}
In my case, I was trying to use mdbreact on windows. Though it installed, But i was getting the above error. I had to reinstall it and everything was ok. It happened to me once two with antd Library
This error can also occur if you're using mobx, and your functional component is wrapped in the mobx observer
function. If this is the case, make sure you are using mobx-react
version 6.0.0 or higher. Older versions will convert your functional component to a class under the covers and all hooks will fail with this error.
See answer here: React Hooks Mobx: invalid hook call. Hooks can only be called inside of the body of a function component
in my case I removed package-lock.json
and node_modules
from both projects and re-install again, and now works just fine.
// project structure
root project
- package-lock.json
- package.json // all dependencies are installed here
- node_modules
-- second project
-- package-lock.json
-- package.json
"dependencies": {
"react": "file:../node_modules/react",
"react-dom": "file:../node_modules/react-dom",
"react-scripts": "file:../node_modules/react-scripts"
},
-- node_modules
Not sure what caused the issue in the first place, as this happened to me before and did same steps as above, and issue was resolved.
I ran into a similar issue, however my situation was a bit of an edge case.
The accepted answer should work for most people, but for anyone else using react hooks in existing react code that uses Radium, note that hooks won't work without workarounds if you use radium.
In my case, i was exporting my component like so:
// This is pseudocode
const MyComponent = props => {
const [hookValue, setHookValue] = useState(0);
return (
// Use the hook here somehow
)
}
export default Radium(MyComponent)
Removing that Radium
wrapper from the export
fixed my issue. If you need to use Radium, resorting to class components and their lifecycle functions may be an easier solution.
Hopefully this helps out at least just one other person.
If your front-end work is in its own folder you might need to install @material-ui/core @material-ui/icons inside that folder, not in the backend folder.
npm i @material-ui/core @material-ui/icons
If all the above doesn't work, especially if having big size dependency (like my case), both building and loading were taking a minimum of 15 seconds, so it seems the delay gave a false message "Invalid hook call." So what you can do is give some time to ensure the build is completed before testing.
Caught this error: found solution.
For some reason, there were 2 onClick
attributes on my tag. Be careful with using your or somebodies' custom components, maybe some of them already have onClick
attribute.
happens also when you use a dependency without installing it. happen to me when i called MenuIcon from '@material-ui/icons/' when was missing in the project.
Here's what fixed it for me. I had the folder node_modules and the files package.json and package-lock.json in my components folder as well as on the root of my project where it belongs. I deleted them from where they don't belong. Don't ask me what I did to put them there, I must have done an npm something from the wrong location.
In my case, changes I've done in package-json cause to problem.
npm install react-redux
fix that
If you're using react-router-dom, make sure to call useHistory() inside the hook.
You may check your Routes. If you are using render instead of component in Route(
Be avare of import issues- For me the error was about failing imports / auto imports on components and child components. Had nothing to do with Functional classes vs Class components.
This is prone to happen as VS code auto importing can specify paths that are not working.
if import { MyComponent } is used and export default used in the component the import should say import MyComponent
If some Components use index.js inside their folder, as a shotcut for the path, and others not the imports might break. Here again the auto import can cause problems as it merges all components form same folder as this {TextComponent, ButtonComponent, ListComponent} from '../../common'
Try to comment out some components in the file that gives the error and you can test if this is the problem.
In my case, the issues was I had cd'd into the wrong directory to do my npm installs. I just re-installed the libraries in the correct directory and it worked fine!
I ran into this same issue while working on a custom node_module
and using npm link
for testing within a cra
(create react app).
I discovered that in my custom node package
, I had to add a peerDependencies
"peerDependencies": {
"@types/react": "^16.8.6 || ^17.0.0",
"react": "^17.0.0",
"react-dom": "^17.0.0"
},
After added that into my package.json
, I then re-built
my custom package. Then in the CRA
, I blew away node_modules
, re npm install
, Re-do the npm link <package>
, and then start the project.
Fixed everything!
My error was with the export at the end, I had the following:
https://i.stack.imgur.com/fh4TN.png
I should have removed the brackets:
https://i.stack.imgur.com/yTOfr.png
Success story sharing
cra
linked to a local library since long time, I'd never see this error message. Just runnpm i
on both project thennpm link
again and it's fine.