I created my app according to the instructions here:
https://reactjs.org/tutorial/tutorial.html#setup-for-the-tutorial
https://github.com/facebook/create-react-app
This is the code in my index.js file:
import React from 'react';
import ReactDOM from 'react-dom/client';
import './index.css';
import Logo from './assets/blacklogo.png'
const Header = () => {
return (
<div className="header">
<div className='headerLogo'>
<img src={Logo} alt='Cool Image'></img>
<h1>'Hello world'</h1>
</div>
</div>
);
}
export default Header;
I have attempted reloading the page and ddouble checking to see if I have loops anywhere
I have discovered the issue, I was writing in index.js as opposed to App.js
Related
I'm starting a small react project (beginner) and when I cut my 'App' component into many small components, such as 'header', it doesn't work. The error started to happen as soon as I cut my header. And to say that the header css doesn't load either. You can see in the element inspector that the React component is present, but it doesn't want to load the css associated with it.
// In App.js
import React from 'react';
import header_type from './header';
class App extends React.Component {
render() {
return (
<div className="window">
<div className="window-body">
<header_type/>
<div className='window_inner'>
<div className="column_left">
</div>
<div className="column_right">
</div>
</div>
</div>
</div>
)
}
}
export default App;
// In header.js
class header_type extends React.Component {
render() {
return (
<div className="window-header" >
</div>
)
}
}
export default header_type;
// In index.js
import React from 'react';
import ReactDOM from 'react-dom';
import App from '../src/components/App';
import '../src/style/window.css';
ReactDOM.render(
<App />, document.getElementById('root')
);
// error :
Search for the keywords to learn more about each warning.
To ignore, add // eslint-disable-next-line to the line before.
WARNING in src\components\App.js
Line 2:10: 'header_type' is defined but never used no-unused-vars
webpack compiled with 1 warning
Thank you in advance for the answers. Have a nice day.
one issue that is present in the above is code is you are exporting a default component from header.js, and importing it as named export in App.js.
In your App.js while importing header component import it as
import header_type from './header';
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/export
I'm working on shopping Cart app, I want to use a Modal Form to display the cart's content and additional options before place the order, that's why I'm using Portals, so far, the source code of my Modal.js looks like this:
import { Fragment } from 'react';
import ReactDOM from 'react';
//import ReactDOM from 'react-dom/client';
import classes from './Modal.module.css';
const Backdrop = (props) => {
return <div className={classes.backdrop} onClick={props.onClose}/>;
};
const ModalOverlay = (props) => {
return (
<div className={classes.modal}>
<div className={classes.content}>{props.children}</div>
</div>
);
};
const portalElement = document.getElementById('overlays');
const Modal = (props) => {
return (
<Fragment>
{ReactDOM.createPortal(<Backdrop onClose={props.onClose} />, portalElement)}
{ReactDOM.createPortal(
<ModalOverlay>{props.children}</ModalOverlay>,
portalElement
)}
</Fragment>
);
};
export default Modal;
When I tried to load the modal form -clicking on an icon- I get this error:
This is the React's version I'm using:
This code used to work on previous version of React (17.x), the weird thing I tried to downgrade but still getting the same error.
My questions are:
In ver 18.x of React, Portals have been changed?
How can I downgrade React properly in order to test my code?
do you have any other suggestions how to overcome this issue using React's 18?
Thanks a lot
I had same error and I solved by importing
import ReactDOM from 'react-dom';
instead of
import ReactDOM from 'react-dom/client';
You completed the following configuration:
npm run eject run this command inside project root directory.
search cssRegex and add the following lines under use: getStyleLoaders({
modules:true,
localIdentName:'[name]__[local]__[hash:base64:5]
Now I just test the following code:
import React from 'react';
import logo from './logo.svg';
import classes from './App.css';
function App() {
return (
<div className={classes.App}>
<p>hello</p>
</div>
);
}
export default App;
As far i did, <div className={classes.App}> this should be converted as like this: <div class="APP_local_ANYTHING">. But no class is being generated. Whats wrong is going on?
if that's all the code you've got, app is not bootstrapped. In order to do so, you would have to add the folowing piece of code:
import * as ReactDOM from 'react-dom';
import App from 'app'; // file with you App component
ReactDOM.render(<App />, document.getElementById('root')) // or any other selector in HTML you want to have your app attached to.
Simple Codepen example
I am just starting a new React project but I am having trouble importing a particular file, which is located in a seperate folder named 'Components', into my app.js file.
Please have a look below at the code I am using to import.
import React, { Component } from 'react';
import { BrowserRouter as Router, Route, NavLink } from 'react-router-dom';
import Category from './Components/Category.js';
import './App.css';
And here is the barely developed Category component, if its of any use in providing a sulution?
const Category=()=>{
return (
<div>
<div class="categories">
<div class="category-choice">
<h1>CAREER</h1>
</div>
<div class="category-choice">
<h1>FINANCE</h1>
</div>
</div>
</div>
)
}
export default Category;
And here is the error message react is providing me with
you need to import React everywhere where you are using JSX. it is important because all JSX elements get transpiled to React.createElement. so React must always be in scope.
import React from 'react' // add this line
const Category=()=>{
return (
<div>
<div class="categories">
<div class="category-choice">
<h1>CAREER</h1>
</div>
<div class="category-choice">
<h1>FINANCE</h1>
</div>
</div>
</div>
)
}
export default Category;
I have setup a basic react app using create-react-app and created my first component. However, the project is not able to build or render due to this error in browser window:
CountDown(...): Nothing was returned from render. This usually means a return statement is missing. Or, to render nothing, return null.
./src/index.js
D:/ReactDev/CountDownReact/countdown/src/index.js:8
Here's my index.js file code:
import React from 'react';
import ReactDOM from 'react-dom';
import './index.css';
import Bulma from 'bulma/css/bulma.css'
import App from './components/App/App';
import registerServiceWorker from './registerServiceWorker';
ReactDOM.render(<App />, document.getElementById('root'));
registerServiceWorker();
and the App.js where I have imported the new component:
import React, {Component} from 'react';
import './App.css';
import CountDown from '../countdown/Countdown';
class App extends Component {
render() {
return(
<div className="App">
Hello React
<CountDown/>
</div>
);
}
}
export default App;
Finally, my Countdown component code:
import React from 'react';
const CountDown = (props) => {
<section class="section">
<div className="hero-body">
<div class="container">
<h1 class="title">Section</h1>
<h2 class="subtitle">
A simple container to divide your page into <strong>sections</strong>, like the one you're currently
reading
</h2>
</div>
</div>
</section>
};
export default CountDown;
Do I need to also import my new component here? How do I solve this issue. Thanks.
Your Countdown component doesn't return anything, you can replace the {} with () in order to have it return.
import React from 'react';
const CountDown = (props) => (
<section class="section">
<div className="hero-body">
<div class="container">
<h1 class="title">Section</h1>
<h2 class="subtitle">
A simple container to divide your page into <strong>sections</strong>, like the one you're currently
reading
</h2>
</div>
</div>
</section>
);
export default CountDown;
That should do it.
CountDown component doesn't return the JSX. You can add an explicit return statement for returning the JSX.
Had the same problem with this:
function Input(props) {
return
<input type={props.type} placeholder={props.placeholder} />
}
Instead it had to be:
function Input(props) {
return <input type={props.type} placeholder={props.placeholder} />
}