React doesn't update when CSS File is changed

React doesn't update when CSS File is changed - javascript

So I'm new to React.
I want to style a simple text and found out how to use styles, but when I want to change something in the CSS I have to restart my React App which always takes 3 Minutes.
I use npm start to start the React server that was created with create-react-app.
How can I let React update when the CSS file is changed?
I have an index.js that looks like this:
import React, { Component } from 'react';
import ReactDOM from 'react-dom';
import App from './Frontend/App.js';
import './Frontend/style/main.css';
ReactDOM.render(<App/>, document.getElementById('root'));
And an App.js that looks like this:
import React, { Component } from 'react';
import ReactDOM from 'react-dom';
import './style/main.css';
class App extends Component {
render() {
var pageHeading = (
<h1 className="pageHeading">bosleeir.it</h1>);
return pageHeading;
}
}
export default App;

Remember that you need to import your CSS in your component. I wouldn't recommend to do it on index.js
I'm assuming your folder structure is:
which could lead me that:
You're using an older version of React
You have modified the structure of your files
So double-check if the path are configured correctly.

Related

Browser page doesn't auto-refreshes in react project

import React from "react";
import "./App.css";
function SecretComponent() {
return <p>Secret2 information for authorised users only </p>;
}
function RegularComponent() {
return <p>Everyone1 can see this component</p>;
}
function App(props) {
if (props.authorized) {
return <SecretComponent />;
} else {
return <RegularComponent />;
}
}
import ReactDOM from "react-dom";
import "./index.css";
import App from "./App";
ReactDOM.render(<App authorized={false} />, document.getElementById("root"));
In my react project in Visual Studio Code when I make a change the browser page refreshes only if a change is made in the App.js file but doesn't refresh when a change is made in the index.js file. I have to refresh the page manually to show the change.

Try this:
npm install react-hot-loader
In app.js , add import { hot } from 'react-hot-loader/root' .
Wrap the App component while exporting export default hot(App) like this.

Getting 'React' must be in scope when using JSX

I am new to react and I tried the following code
person.js
const element = <h1>Hello world</h1>;
export default element;
App.js
import React, { Component } from 'react';
import ReactDOM from 'react-dom'
import Person from '../src/person/person';
function Hello() {
return Person.element;
}
class App extends Component {
render() {
return (
<div className="App">
<Hello></Hello>
</div>
);
}
}
export default App;
But getting the below errors
work/my-app/src/person/person.js
3:17 error 'React' must be in scope when using JSX react/react-in-jsx-scope
When I changed to a simple hello word as below, then it works fine.
person.js
const element = 'hello world';
export default element;
I tried with different ways by checking different forum
importing the ReactDom
in person.js changed to module.exports=element

The use of HTML within JS code is known as JSX. The <h1>...</h1> is JSX. You need to import React before you use JSX. Simply shift the import statements before any use of JSX.
person.js
import React, { Component } from 'react';
import ReactDOM from 'react-dom'
import Person from '../src/person/person';
const element = <h1>Hello world</h1>;
export default element;

You need to import React in every file that exports a component (App in this case).

The latest React 17 Version: No need to include React in the scope
If you are struggling with ESlint or run-time CRA warnings, follow these temporary steps to fix until CRA v4 is released: https://github.com/facebook/create-react-app/issues/9850

Module not found :Can't resolve './components/counter' in 'C:/...demo\counter-app\src'

I am totally new to React and i'm following tutorials (Programming with MOSH) in youtube but i'm stuck with this error, unable to resolve after finding similar questions.
index.js
import React from 'react';
import ReactDOM from 'react-dom';
import './index.css';
import App from './App';
import * as serviceWorker from './serviceWorker';
import "bootstrap/dist/css/bootstrap.css";
import Counter from './components/counter';
//import * as Counter from './components/counter'; //tried this method too
ReactDOM.render(
<Counter />,
document.getElementById('root')
);
// If you want your app to work offline and load faster, you can change
// unregister() to register() below. Note this comes with some pitfalls.
serviceWorker.unregister();
counter.jsx
import React, { Component } from 'react';
class Counter extends Component {
render() {
return <h1> Hello world</h1>;
}
}
export default Counter;
in command prompt i had done npm install and npm start after deleting package-lock.json but still the same error
folder structure
Thanks in advance.

Move your components folder inside the SRC this will fix it

Either move components folder inside src folder or change the reference in the import statement to '../component/counter'

How to use script tags in React

I am trying to use a html and CSS template on create-react-app. I can convert all of the HTML to JSX without any issues and render the CSS just fine. I cant get the Script tags that home with the template to work though

I think you would write script tags in Reactjs the same way you would in HTML. Like this:
<script src="fooLink.js"></script>
(fooLink.js being any link.)
If you want to go further with React, try looking at this article:
https://reactjs.org/tutorial/tutorial.html
Or post the code you are having trouble with so we can help you.

I am not sure I understand but can't you add the script tags to your index.html file . The one where you have a div (usually) targeted by the render function of ReactDom (render( , document.getElementById('my target div'))

React works with classes (ES6) and functions which are called as
components. you can create one and import the created component in
your jsx (written inside the render() of the component)
//your first component(js)
import React, {Component} from 'react';
class ComponentOne extends React {
render() {
return <div>some text or {value}</div>
}
}
//your second component
import React, {Component} from 'react';
import ComponentOne from 'your path here';
class ComponentTwo extends React {
render() {
return <ComponentOne>;
}
You can learn more from https://reactjs.org/

npm install --save react-script-tag
then
import React, { Component } from 'react';
import ScriptTag from 'react-script-tag';
class Demo extends Component {
render() {
return (<ScriptTag isHydrating={true} type="text/javascript" src="some_script.js" />);
}
}

"Import in body of module; reorder to top import/first" Across Many Files

I have the same error as this answer, except instead of it just occurring in one file it is occurring in many; once I fix it for one file, another just pops up with the same error. I've seen this answer but whenever I run react-scripts start a node_modules folder is created in my src, so that solution isn't viable.
It would be too time consuming to have to fix every file that has this error every time I compile, so how can I get rid of this error? It seems to just be an eslint issue.

you will get this error if you declare variable in between your imports,
import React from 'react';
import axios from 'axios';
const URL = process.env.REACT_APP_API_BASE;
import demoXLXSFile from '../../assets/others/Demo.xlsx';
import './student.list.styles.scss';
declare variables after importing everything,
import React from 'react';
import axios from 'axios';
import demoXLXSFile from '../../assets/others/Demo.xlsx';
import './student.list.styles.scss';
const URL = process.env.REACT_APP_API_BASE;

I found this issue while I was using React.lazy in my existing project. I got this error Failed to compile. :- Import in body of module; reorder to top import/first (with create-react-app).
import React from 'react';
import SelectField from '../inputs/SelectField';
const Questions = React.lazy(() => import('./questions'))
import _ from 'lodash';
Solution:-
Only reorder the position i.e. put all import on top then react.lazy.
import React from 'react';
import SelectField from '../inputs/SelectField';
import _ from 'lodash';
const Questions = React.lazy(() => import('./questions'))

I got this same error when I added an extra semicolon ';' at the end of an import statement.
I suggest removing any extraneous semicolons. This should make the error go away.

Moving every import statement to the top of the file solves the issue.

Happened to me when I put require before import like this:
require('dotenv').config()
import React from 'react';
import ReactDOM from 'react-dom';
...
Solution: Put the require after the imports

If You are using Component Lazy loading then always put lazy load component import code below normal import code.
Correct Example
import First from './first'
const Second = React.lazy(()=>import("./Second))
Incorrect Example
const Second = React.lazy(()=>import("./Second))
import First from './first'

I came across this issue too. I found that you must import all ES6 modules at the top level of your JavaScript files."... the structure of ES6 modules is static, you can’t conditionally import or export things. That brings a variety of benefits.
This restriction is enforced syntactically by only allowing imports and exports at the top level of a module:"
From Dr. Axel Rauschmayer’s Exploring JS:

Wrong
1.
import React ,{useState ,useEffect} from 'react';
import './App.css';
import Post from './Post';
import db from "./firebase"
Right
2.
import React ,{useState ,useEffect} from 'react';
import './App.css';
import Post from './Post';
import db from "./firebase.js"
//this is code firebase.js
const db = firebaseApp.firestore();
const auth = firebase.auth();
const storage = firebase.storage();
export default {db,auth,storage};
When I change the firebase into firebase.js in Snippet 2.
My Error vanished

I had forgotten to add from.
Before:
import UpperBlock;
After:
import UpperBlock from "../components/dashboard/shared/UpperBlock";
Make sure you import well your component and then stop the server and restart it again. It worked for me.

I forgot to add {Component} after importing 'react' library to my project, this solved my issue.

Move all of your imports to the top of the file.
Even in case of a require (that is written in between import statements), this error will come.
e.g.
import 'some_module';
require('some_file');
import 'some_other_module');
This would result in an error.
You would want to do this instead:
import 'some_module';
import 'some_other_module');
require('some_file');

I was facing the same issue when I installed chat.js library in my reactJs project. I solved this issue by moving my chart.Js import to the index.js file
index.js file:
import React from "react";
import ReactDOM from "react-dom";
import { Chart as ChartJS, ArcElement, Tooltip, Legend } from "chart.js"; <--- imported
import "./index.css";
import App from "./App";
ChartJS.register(ArcElement, Tooltip, Legend); <---- imported

If you're experiencing this error in modern versions of react(current version 18.0.0) make sure you're making all your imports before the ReactDOM.createRoot declaration.
For example, I got the error with:
import App from "./App";
import reportWebVitals from "./reportWebVitals";
const root = ReactDOM.createRoot(document.getElementById("root"));
import { Provider } from "./context";
This will result in an error. Instead, import everything before the createRoot:
import App from "./App";
import reportWebVitals from "./reportWebVitals";
import { Provider } from "./context";
const root = ReactDOM.createRoot(document.getElementById("root"));
This will fix the error. Simple fix but it's easy to miss

If I put double Semicolon behind the importing statement than I got "error".you can see difference between two pictures in import './index.css'; is different
For Example :-
import React from 'react';
import ReactDOM from 'react-dom/client';
import './index.css';;
import 'tachyons';
import {robots} from "./Robots";
import reportWebVitals from './reportWebVitals';
import CardList from './CardList';

Develop Reference

JavaScript is the programming language of the Web.

React doesn't update when CSS File is changed - javascript

Related

Browser page doesn't auto-refreshes in react project

Getting 'React' must be in scope when using JSX

Module not found :Can't resolve './components/counter' in 'C:/...demo\counter-app\src'

How to use script tags in React

"Import in body of module; reorder to top import/first" Across Many Files

Categories

Resources