I'm pretty new to React and I've been trying to set up a REACT app. However, I always get a blank page. Can anyone help?
HTML Code (index.html)
<html>
<head>
<meta charset="UTF-8" />
<title>Home</title>
</head>
<body>
<div id="root"></div>
<script src="index.js" type="text/babel"></script>
</body>
</html>
Javascript (index.js)
import React from "react"
import ReactDOM from "react-dom"
const page = (
<div>
<h1>My page</h1>
</div>
)
ReactDOM.render(page, document.getElementById("root"));
And yes, I am using a live server to run this code.
Browsers don't understand the text/babel MIME type.
It is there for Babel to search the DOM for scripts that it should process to convert from whatever they are (JS + JSX in this case) to JS.
You haven't included Babel in your page though.
You have a further problem in that inside your script you have import statements which depend on Node.js module resolution (and you're using a browser, not Node).
You should start at the beginning of the React guide.
You currently have an odd mix of about 20% of the quick guide to adding React to a website and 5% of using a Node.js based toolchain to transpile your code.
I recommend starting with create-react-app as it gives you a robust, performant foundation to get started with.
Related
I would like to add a React component in one of the divs from a static HTML page. I'm doing so instead of converting the entire page into React since I only need React for few parts of my web page. I followed the instructions on https://reactjs.org/docs/add-react-to-a-website.html. And my questions are:
Is it okay to do that, or is it rather recommended that I implement my website entirely in React?
I did what the aforementioned page told me, but the section I used React did not get implemented when I displayed it on my browser (my IDE is WebStorm). Is there a specific script (like yarn start when using React framework) that I have to run in order to compile?
Checkout this minimal example. You need to include 3 scripts
react.development.js (the react lib)
react-dom.development.js (react lib to interact with dom)
babel.min.js (converts react JSX into browser compatible JS)
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<title>Hello World</title>
<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>
<!-- Don't use this in production: -->
<script src="https://unpkg.com/#babel/standalone/babel.min.js"></script>
</head>
<body>
<div id="root"></div>
<script type="text/babel">
function HelloWorld(props){
return <h1>{`Hello, world! ${props.name}`}</h1>;
}
ReactDOM.render(
<HelloWorld name="James"/>,
document.getElementById('root')
);
</script>
</body>
</html>
Note: this is a great way to try React but it's not suitable for production.
It slowly compiles JSX with Babel in the browser and uses a large development build of React.
Read this section for a production-ready setup with JSX:
https://reactjs.org/docs/add-react-to-a-website.html#add-jsx-to-a-project
In a larger project, you can use an integrated toolchain that
includes JSX instead:
https://reactjs.org/docs/create-a-new-react-app.html
You can also use React without JSX, in which case you can remove
Babel: https://reactjs.org/docs/react-without-jsx.html
SOURCE : https://raw.githubusercontent.com/reactjs/reactjs.org/master/static/html/single-file-example.html
Yes, it's ok. No, your entire website doesn't need to use React.
It should work as described in the tutorial you linked, you don't need to compile anything. The scripts invoked by yarn or npm in frontend projects usually bundle javascript modules together and transpile (we don't call it compiling since there is no machine code as output) from a modern version of EcmaScript into an older, established version of EcmaScript that is understood by most browsers. But for your small example, none of this really matters. In order to identify why your code doesn't work, it would be helpful to see it.
I've been trying to run some of the basic React examples in Electron App, but nothing shows up, even though there is no errors.
Here's a file:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<div id="root"></div>
<script type="text/babel">
const React = require('react');
const ReactDOM = require('react-dom');
ReactDOM.render(
<h1>Hello World</h1>,
document.getElementById('root')
);
</script>
</body>
</html>
I have the following packages installed: react, react-dom and electron.
Am I doing something wrong? Thanks in advance!
type="text/babel" isn't recognized by browsers as a valid script type, so it'll just ignore it and skip over it completely, hence the lack of any error. You need to include the babel script to make it parse, like so:
<body>
<div id="root"></div>
<script src="https://unpkg.com/babel-standalone#6/babel.min.js"></script>
<script type="text/babel">
// your react code here
</script>
</body>
This is fine for exploration and prototyping, but it's not good if you want to release the app for others to use. Having babel parse the script on-the-fly can weigh on performance and memory usage.
Instead, look into a tutorial on how to pre-compile your scripts and run them that way. This boilerplate could serve as a good reference.
I'm creating a web app using node and react. Rather than seperate Node and React apps I want to integrate React into it. So rather than a react app, I tried importing react CDN into the index.html. My server serves the index.html perfectly, but I'm getting an error in the react component.
this is my index.html
<html>
<head>
<meta charset="utf-8">
<title>React Powered chat App</title>
</head>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.2.0/umd/react.development.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.2.0/umd/react-dom.development.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/socket.io/2.0.4/socket.io.js" charset="utf-8"></script>
<script src="/scripts/main.js" charset="utf-8"></script>
<body>
Hello !
<div id ='App'></div>
</body>
</html>
and this is my main.js
class App extends React.Component {
render(){
return (
<div>
Hello !
</div>
);
}
}
ReactDOM.render(<App />, document.getElementById('App'));
The error I'm getting is
Uncaught SyntaxError: Unexpected token < main.js:4
What have I done wrong? Isn't it possible to use react with CDN ?
And first when I used react/cjs/react.development libraries I got more errors. Then after reading this stackoverflow question I use /react/umd/ libraries. So what's the difference between cjs and umd CDN libraries ?
The code doesn't work because react uses JSX (HTML inside javascript), which cannot be read by the browser and needs to be transpiled to ordinary javascript which can be read by browsers. One such transpiler is babel. Your code doesn't work due to the absence of transpiler.
You can use create-react-app, which comes bundled with the transpiler and everything that you'll need to get started with react. And as I understand, since you want to add your express backend, here is a tutorial that will help you get started with attaching create-react-app to your express backend. Hope this helps.
Since JSX (the HTML code sprinkled in the JavaScript) is not regular JavaScript or ES6 code, you cannot load it directly in your browser.
So the problem is not getting the React library from a CDN, that’s fine.
The problem is that you have to transpile your main.js file to regular JavaScript code, for example using Babel.
The most commonly used tool to do this transpilation with Babel automatically is webpack.
If you don’t want to learn how to set up webpack and Babel in detail, I recommend to use create-react-app, this takes the burden of setting up all of the boilerplate from your shoulders and creates a JavaScript bundle that you can use directly in your browser.
Note: if you do end up using create-react-app, you don’t need to get the React lib from a CDN, it will already be included in the bundle.
You also need to add babel cdn in the Html file which would convert JSX to JS
<script src="https://unpkg.com/babel-standalone#6/babel.min.js"></script>
I've wanted to create simple desktop app which uses React JS for data presentation.
However, I'm overwhelmed with so many modules and technologies. There is an electron react boilerplate which very complicated for starters like me.
I have simple project with these libs:
electron as dev
react
react-dom
I have main.js in my root path of my project which launches electron and it is taken from this quickstart example
I have index.html file where my JSX should be loaded:
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Hello World!</title>
</head>
<body>
<div id="react-view"></div>
</body>
<script type="text/jsx">
// You can also require other files to run in this process
require('./scripts/application');
</script>
</html>
There are scripts/application.js file where my JSX will be populated to my <div id="react-view"></div>.
My App.jsx is very simple:
import React, {Component} from 'react'
class App extends Component{
render() {
return <h1>Hello From React</h1>;
}
}
export default App;
My application.js file looks like this:
import React from 'react';
import ReactDom from 'react-dom/server';
import App from 'components/App';
ReactDom.render(<App/>, document.getElementById("react-view"));
When I launch my electron application it opens me a window with empty content, which means that my JSX is not loaded. And it does not throw any error messages
What did I miss?
Here is the problem - no one understands JSX except a transpiler.
Two ways, you can get JSX work -
use a browser based/client side transpiler (use only for development
purpose)
include this file as a script tag
<script src="https://cdnjs.cloudflare.com/ajax/libs/babel-core/5.8.34/browser.js"></script>
use type="text/babel" on your script tag which loads your JSX
<script type="text/babel" src="index.js"></script>
checkout the sample here - https://github.com/rabibiswal/reactdemo/tree/master/hello-world-jsx
user a server based transpiler - e.g. Babel
You can use different tools like webpack etc.
checkout the sample here -
https://github.com/rabibiswal/reactdemo/tree/master/hello-world-react-es5
You need to install node and use npm install and npm run build to get this code working
I'm building a NW.js app, currently with babel-standalone and React. I can use ES6 import, but ES6 export on the other hand does not work, console spits out unexpected token export. What's going on?
index.html:
<html>
<head>
<meta charset="utf-8">
<script src="assets/react.min.js" charset="utf-8"></script>
<script src="assets/react-dom.min.js" charset="utf-8"></script>
<script src="assets/babel.min.js" charset="utf-8"></script>
</head>
<body>
<script type="text/babel" src="script/App.js"></script>
</body>
</html>
(yes, Babel indeed works, since React stuff inside runs OK)
In app.js:
import Lib from "./script/lib.js";
(and it's indeed exporting lib.js correctly, since that is the file responsible for the error)
In script/lib.js:
export default class {...};
I'm aware I can use Node modules instead, or even HTML script loading, but that's beside the point. I want to know why export doesn't work even if Babel doesn't seem to be broken, and even import works fine.
The problem is that Babel doesn't see files that were loaded via require, and they are loaded as they are, without transpilation.
There can be several ways to work this around, but the easiest one will be using Babel at build step.
Process your source code and then load processed code nw.js environment. The example how to do that you can find at this boilerplate project