ReactDOM not rendering anything - reactjs

index.html:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>React App</title>
</head>
<body>
<script src='./index.js' type='text/babel'></script>
<div id="root"></div>
</body>
</html>
index.js:
import React from 'react';
import ReactDOM from 'react-dom';
ReactDOM.render(
<h1>Hello world</h1>,
document.getElementById('root')
);
The webpage is completely empty, tried reinstalling react and react-dom several times. There's no compilation errors from babel or node. The webpage is just empty.

Here is the simple example to get started!
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<title>React App</title>
<script src="https://unpkg.com/react#latest/dist/react.js"></script>
<script src="https://unpkg.com/react-dom#latest/dist/react-dom.js"></script>
<script src="https://unpkg.com/babel-standalone#latest/babel.min.js"></script>
<script type="text/babel">
var ex = <h1>It worked!</h1>;
ReactDOM.render(
ex,
document.getElementById('root')
);
</script>
</head>
<body>
<div id="root"/>
</body>
</html>

First you need to add react, reactdom, babel files in your index.html file.
Option 1:
then you can able to see the output by moving the index.js script inside the index.html as below. where you can see the output by opening the index.html file.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>React App</title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.4.2/react.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.4.2/react-dom.js"></script>
<script src="https://unpkg.com/babel-standalone#6.15.0/babel.min.js"></script>
</head>
<body>
<div id="app"></div>
<script type="text/babel" >
ReactDOM.render(
<h1>Hi! My react App</h1>,
document.getElementById('app')
)
</script>
</body>
</html>
Option 2: Adding external js file:
If you are adding some external react js file,
index.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>React App</title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.4.2/react.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.4.2/react-dom.js"></script>
<script src="https://unpkg.com/babel-standalone#6.15.0/babel.min.js"></script>
</head>
<body>
<div id="root"></div>
<script type="text/babel" src="index.js" >
</script>
</body>
</html>
index.js:
ReactDOM.render(
<h1>Hi Now your react app works</h1>,
document.getElementById('root')
);
first you have to create an http server. Else you will see some file load error in console something like Cross origin requests are only supported for protocol schemes: http, data, chrome, chrome-extension, https.
Steps to create simple http-server using node:
1) Install node JS -> https://nodejs.org/en/download/
2) Run: npm install -g http-server
3) Run: http-server [folderpath] // folder path which contains index.html
once you started the http server, you will see the msg like below
Starting up http-server, serving [folder name]
Available on:
http://127.0.0.1:8080
http://192.168.1.6:8080
Now access the URL (http://127.0.0.1:8080) you could see the index.html output. Hope it helps!!!

Include the index.js after the dom element div creation:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>React App</title>
</head>
<body>
<div id="root"></div>
<script src='./index.js' type='text/babel'></script>
</body>
</html>
When index.js is executing, it requires the dom element to fill it with the react rendering

Related

Reactjs code is not rendering HTML component properly

I am new to React and would like to ask why the following code in vs code wont render the h1 component in my html page?
When I run the html page, it just shows empty page. Anyone know what is happening?
Code as follows:
My index.html code as follows:
<!DOCTYPE html>
<html lang="en">
<head>
<script crossorigin src="https://unpkg.com/react#17/umd/react.development.js"></script>
<script crossorigin src="https://unpkg.com/react-dom#17/umd/react-dom.development.js"></script>
<script src="https://unpkg.com/babel-standalone#6/babel.min.js"></script>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>React</title>
</head>
<body>
<div id="root"></div>
<script src="index.js" type="text/babel"></script>
</body>
</html>
My index.js code as follows:
ReactDOM.render(<p>Hello, everyone!</p>,document.getElementById("root"))
Whenever I run the html file, it just shows blank page rather than "Hello, everyone!". Does anyone know what is going on here?
index.js
import React from 'react';
import ReactDOM from 'react-dom';
import './index.css';
import App from './App';
ReactDOM.render(
<React.StrictMode>
<App />
</React.StrictMode>,
document.getElementById('root')
);
React uses JSX to render all the components. This means in simple terms, it collects all the components and converts them into an HTML page.
React renders each component as a tree. So it is not advisable to add all your code to a single component. As in your case, you tried to print Hello Everyone! on the render function without specifying the HTML tag.
App.js
import React from "react";
function App() {
return (
<div>
<h1>Hello Everyone</h1>
</div>
);
}
export default App;
If you're wondering how I'm importing App.js and CSS files, It is called path specifying for the files. If the files are present are on the same folder then use ./filename.extension(css/js)
What is React.StrictMode?
It renders all the child components in strict mode.
This prevents certain actions being taken and throws errors/warnings if there are any
Most importantly it does a lot of checking which will be really helpful to correct all the possible errors.
You should not open the HTML page to see changes instead use any package managers to run the react code. For Example:
npm start or yarn start
All the best! 😁
<html>
<head>
<script
src="https://unpkg.com/react#17/umd/react.development.js"
crossorigin
></script>
<script
src="https://unpkg.com/react-dom#17/umd/react-dom.development.js"
crossorigin
></script>
<script src="https://unpkg.com/#babel/standalone/babel.min.js"></script>
</head>
<body>
<div id="root"></div>
<script type="text/babel">
ReactDOM.render(<p>Hello world!</p>, document.getElementById("root"));
</script>
</body>
</html>
here you have to specify the data-preset="react"
<script src="index.js" type="text/babel" data-preset="react"></script>
index.html
<!DOCTYPE html>
<html lang="en">
<head>
<script crossorigin src="https://unpkg.com/react#17/umd/react.development.js"></script>
<script crossorigin src="https://unpkg.com/react-dom#17/umd/react-dom.development.js"></script>
<script src="https://unpkg.com/babel-standalone#6/babel.min.js"></script>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>React</title>
</head>
<body>
<div id="root"></div>
<script src="index.js" type="text/babel" data-preset="react"></script>
</body>
</html>

Can we access react component once bundle it?

Steps:
I have many custom components. Hence, I created standalone package.
I did it bundle using webpack.
Include that bundle file in HTML page using script tag.
Now, I just want to use it in HTML page like below example, but I cant access it.
<!DOCTYPE html />
<html>
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<script src="https://unpkg.com/babel-standalone#6/babel.min.js"></script>
<script src="https://unpkg.com/react#16/umd/react.development.js"></script>
<script src="https://unpkg.com/react-dom#16/umd/react-dom.development.js"> </script>
<script src="build.js"></script>
</head>
<body>
<div id="root"></div>
<script type="text/jsx">
ReactDOM.render(<CustomButton />, document.getElementById('root'));
</script>
</body>
</html>
Is it possible to access component once bundle ?

Can I use React and JSX in Javascript without installing the Node.js?

I'm working on a project, which has already a webserver. The webserver runs PHP and it is limited. Many software cannot be installed.
I understand that React does not require any installation but adding JSX to a project needs to run these commands:
Step 1: Run npm init -y
Step 2: Run npm install babel-cli#6 babel-preset-react-app#3
Unfortunately, I cannot add NodeJS to the webserver.
JSX coding syntax would be very useful for me using the JavaScript files.
Option for adding it to HTML
I understand that I could add JSX to an HTML file:
<script type="text/babel">
ReactDOM.render(
<h1>Hello, world!</h1>,
document.getElementById('root')
);
</script>
But I would like to use in .js files.
Examples
I have 2 examples:
Example is working but it has no JSX.
Example has JSX but it is not working.
The HTML file is the same.
1. Example project: Unexpected token error with JSX
const myelement1 = <h1>JSX should work</h1>;
ReactDOM.render(
myelement1,
document.getElementById('reactRoot')
);
<!DOCTYPE html>
<html lang="en" dir="ltr">
<head>
<meta charset="utf-8">
<title></title>
</head>
<body>
<h1>My React example page</h1>
<div id="reactRoot"></div>
<script src="https://unpkg.com/react#16/umd/react.development.js" crossorigin></script>
<script src="https://unpkg.com/react-dom#16/umd/react-dom.development.js" crossorigin></script>
<script src="https://unpkg.com/babel-standalone#6/babel.min.js"></script>
</body>
</html>
2. Example project: React is working without JSX
const myelement2=React.createElement('h1', {}, 'No JSX!');
ReactDOM.render( myelement2, document.getElementById('reactRoot'));
<!DOCTYPE html>
<html lang="en" dir="ltr">
<head>
<meta charset="utf-8">
<title></title>
</head>
<body>
<h1>My React example page</h1>
<div id="reactRoot"></div>
<script src="https://unpkg.com/react#16/umd/react.development.js" crossorigin></script>
<script src="https://unpkg.com/react-dom#16/umd/react-dom.development.js" crossorigin></script>
<script src="https://unpkg.com/babel-standalone#6/babel.min.js"></script>
</body>
</html>
My Question
How could I fix 1. Example project, if no program installation is possible?
you have to set type attribute as text/babel, this way the problems will be resolved, e.g:
<html>
<body>
<div id="reactRoot"></div>
<script type="text/babel">
const myelement1 = <h1>JSX should work</h1>;
ReactDOM.render(
myelement1,
document.getElementById('reactRoot')
);
</script>
<script src="https://unpkg.com/react#16/umd/react.development.js" crossorigin></script>
<script src="https://unpkg.com/react-dom#16/umd/react-dom.development.js" crossorigin></script>
<script src="https://unpkg.com/babel-standalone#6/babel.min.js"></script>
</body>
</html>

Reactdom does not render a simple text

I tried to render a simple text, but it renders nothing. I already installed react, reactdom, webpack, and bable. Any idea on why is it not working?
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>React and Spring Boot</title>
</head>
<body>
<div id='root'></div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.6.0/react.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.6.0/react-dom.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/babel-core/5.8.23/browser.min.js"></script>
<script type="text/babel">
import React from 'react';
import ReactDOM from 'react-dom';
ReactDOM.render(
<h1>Test</h1>, document.getElementById('root')
);
</script>
</body>
</html>
Removing import statements works for me. Please check the working snippet.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>React and Spring Boot</title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.6.0/react.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.6.0/react-dom.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/babel-core/5.8.23/browser.min.js"></script>
</head>
<body>
<div id='root'></div>
<script type="text/babel">
ReactDOM.render(
<h1>Test</h1>, document.getElementById('root')
);
</script>
</body>
</html>
It works...its just that import is not understood by the browser
ReactDOM.render(
<h1>Test</h1>, document.getElementById('root')
);
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.6.0/react.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.6.0/react-dom.js"></script>
<div id="root"></div>

React starter kit Hello World program error

I am trying to make an "Hello World" program as suggest on react tutorial.
But I created helloworld.js under src and helloworld.html in root. When I try to run my helloworld.html nothing happens (at all). And when I try to run helloworld.js error described below comes.
Is it some issue with babel?
Your first question, why helloworld.html returns nothing at all:
You should not need to add src="src/helloworld.js" in the tag. Otherwise the will try to load your helloworld.js (which causes your second question). I have created a plunker - it works without the src="src/helloworld.js"
html file:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Hello React!</title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.3.0/react.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.3.0/react-dom.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/babel-core/5.8.34/browser.min.js"></script>
</head>
<body>
<div id="example"></div>
<script type="text/babel">
ReactDOM.render(
<div>test</div>,
document.getElementById('example')
);
</script>
</body>
</html>
Demo:
http://plnkr.co/edit/ONtPtVkCsnEqNYYtDFAv?p=preview
For your second question. I guess you try to separate the script to a new file out from the helloworld.html. You do not need import because you add the react.js and react-dom.js in the html's head tag already. ReactDOM.render is already known when you load the src/helloworld.js from the script tag.
html file:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Hello React!</title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.3.0/react.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.3.0/react-dom.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/babel-core/5.8.34/browser.min.js"></script>
</head>
<body>
<div id="example"></div>
<script type="text/babel" src="src/helloworld.js">
</script>
</body>
</html>
src/helloworld.js
ReactDOM.render(
<h1>Hello, world</h1>,
document.getElementById('example')
);
Demo:
http://plnkr.co/edit/9uNkyaz65A4FMTHwdCtr?p=preview
Edit:
Click on the browser, for example, I clicked Chrome and got Hello World!:

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