127

i am just starting with Reactjs and was writing a simple component to display
li tag and came across this error:

Unexpected token '<'

I have put the example at jsbin below http://jsbin.com/UWOquRA/1/edit?html,js,console,output

Please let me know what i am doing wrong.

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19 Answers 19

Reset to default
72

I solved it using type = "text/babel"

<script src="js/reactjs/main.js" type = "text/babel"></script>
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1 Comment

That's correct, use "text/babel" instead of "text/jsx". Reference the babel core url -> cdnjs.cloudflare.com/ajax/libs/babel-core/5.8.24/browser.min.js
31

UPDATE: In React 0.12+, the JSX pragma is no longer necessary.

Make sure include the JSX pragma at the top of your files:

/** @jsx React.DOM */

Without this line, the jsx binary and in-browser transformer will leave your files unchanged.

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3 Comments

But <script type="text/jsx"> is
using babel I had to throw in type="text/babel". Brave new world of javascript
this helped in my circumstances: stackoverflow.com/questions/33460420/…
31

The issue Unexpected token '<' is because of missing the babel preset.

Solution: You have to configure your webpack configuration as follows

{
  test   : /\.jsx?$/,
  exclude: /(node_modules|bower_components)/,
  loader : 'babel',
  query  : {
    presets:[ 'react', 'es2015' ]
  }
}

here .jsx checks both .js and .jsx formats.

you can simply install the babel dependency using node as follows

npm install babel-preset-react
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7 Comments

There's nothing in the question indicating that the original poster is using babel.
He said he is just starting with Reactjs , for React babel preset have to be use.May be the webpack configuration missed the babel preset
There's nothing in the question indicating the the original poster is using webpack either. Neither of those are required for working with React although they are both handy.
@Nuwa thank you. npm install babel-preset-react solved my problem.
if you have .babelrc file in the project just "presets": ["env", "react", "es2015"] and that's it!!
|
24

in my case, i had failed to include the type attribute on my script tag.

<script type="text/jsx">
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Comments

8

I have this error and could not solve this for two days.So the fix of error is very simple. In body ,where you connect your script, add type="text/jsx" and this`ll resolve the problem.

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2 Comments

can you also give an explanation for your answer?
I think when you give type="text/jsx" you worn compiler to know what type of document or file this is.
7

You need to either transpile/compile that JSX code to javascript or use the in-browser transformator

Look at http://facebook.github.io/react/docs/getting-started.html and take note of the <script> tags, you need those included for JSX to work in the browser.

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9 Comments

Yes i know, below is the updated jsbin link
That jsbin seems to have their own way of executing the JS, the error is from within their code.
But it is the same error and at same line number. Also, is there any other reason why such an error will happen if i am using the same code as provided in the link
jsfiddle.net/9st5Q here is your code in a jsfiddle, where React works fine.
make sure you set the type="text/jsx" in <script type="text/jsx"> tag, if you want please paste your whole code into a hastebin.org paste
|
3

Here is a working example from your jsbin:

HTML:

<!DOCTYPE html>
<html>
<head>
<script src="//fb.me/react-with-addons-0.9.0.js"></script>
<meta charset=utf-8 />
<title>JS Bin</title>
</head>
<body>
  <div id="main-content"></div>
</body>
</html>

jsx:

<script type="text/jsx">
/** @jsx React.DOM */
var LikeOrNot = React.createClass({
    render: function () {
      return (
        <p>Like</p>
      );
    }
});

React.renderComponent(<LikeOrNot />, document.getElementById('main-content'));
</script>

Run this code from a single file and your it should work.

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Comments

3

Check if .babelrc is inside your application root folder, not inside a subfolder. if that's the case move file to root.

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Comments

2

if we consider your real site configuration, than you need to run ReactJS in the head

<!-- Babel ECMAScript 6 injunction -->  
<script src="https://unpkg.com/babel-standalone@6/babel.min.js"></script>

and add attribute to your js file - type="text/babel" like

<script src="../js/r1HeadBabel.js" type="text/babel"></script>

then the below code example will work:

ReactDOM.render(
  <h1>Hello, world!</h1>,
  document.getElementById('root')
);
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Comments

2

If you're like me and prone to silly mistakes, also check your package.json if it contains your babel preset:

  "babel": {
    "presets": [
      "env",
      "react",
      "stage-2"
    ]
  },
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Comments

1

For correct tag parsing you'll need to use this babel version : https://cdnjs.cloudflare.com/ajax/libs/babel-core/5.8.24/browser.js and attribute "type='text/babel'" in the script. Besides, your custom script should be within "body" tags.

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Comments

1

You can use code like this:

import React from 'react';
import ReactDOM from 'react-dom';

var LikeOrNot = React.createClass({
    displayName: 'Like',
    render: function () {
      return (
        React.createElement("li", null, "Like")
      );
    }
});
ReactDOM.render(<LikeOrNot />, document.getElementById('main-content'));

And don't forget add <div id='main-content'></div> into the body in your html

But in your package.json file you should use this dependencies:

  "dependencies": {
...
    "babel-core": "^6.18.2",
    "babel-preset-react": "^6.16.0",
...
}
"devDependencies": {
...   
    "babel": "^6.5.2",
    "babel-loader": "^6.2.7",
    "babel-preset-es2015": "^6.18.0",
    "jsx-loader": "^0.13.2",
...
}

It's work for me but i used webpack also, with this options (into webpack.config.js):

  module: {
    loaders: [
      { 
        test: /\.jsx?$/,         // Match both .js and .jsx files
        exclude: /node_modules/, 
        loader: "babel-loader", 
        query:
        {
          presets: ['es2015', 'react']
        }
      }
    ]
  }
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Comments

1

heres another way you can do it html 

<head>
    <title>Parcel Sandbox</title>
    <meta charset="UTF-8" />
</head>

<body>
     <div id="app"></div>

    <script src="src/index.js"></script>
</body>

</html>

index.js file with path src/index.js

import React from "react";
import { render } from "react-dom";

import "./styles.scss";

const App = () => (
  <div>
    <h1>Hello test</h1>
  </div>
);

render(<App />, document.getElementById("app"));

use this package.json will get u up and running quickly

{
  "name": "test-app",
  "version": "1.0.0",
  "description": "",
  "main": "index.html",
  "scripts": {
    "start": "parcel index.html --open",
    "build": "parcel build index.html"
  },
  "dependencies": {
    "react": "16.2.0",
    "react-dom": "16.2.0",
    "react-native": "0.57.5"
  },
  "devDependencies": {
    "@types/react-native": "0.57.13",
    "parcel-bundler": "^1.6.1"
  },
  "keywords": []
}
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Comments

1

Use the following code. I have added reference to React and React DOM. Use ES6/Babel to transform you JS code into vanilla JavaScript. Note that Render method comes from ReactDOM and make sure that render method has a target specified in the DOM. Sometimes you might face an issue that the render() method can't find the target element. This happens because the react code is executed before the DOM renders. To counter this use jQuery ready() to call the render() method of React. This way you will be sure about DOM being rendered first. You can also use defer attribute on your app script.

HTML code:

<!DOCTYPE html>
<html>
<head>
<meta charset=utf-8 />
<title>JS Bin</title>
</head>
<body>
  <div id='main-content'></div>
<script src="CDN link to/react-15.1.0.js"></script>
<script src="CDN link to/react-dom-15.1.0.js"></script>
  
</body>
</html>

JS code:

var LikeOrNot = React.createClass({
    render: function () {
      return (
        <li>Like</li>
      );
    }
});

ReactDOM.render(<LikeOrNot />,
                document.getElementById('main-content'));
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Comments

0

In my case, besides the babel presets, I also had to add this to my .eslintrc:

{
  "extends": "react-app",
  ...
}
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Comments

0

Although, I had all proper babel loaders in my .babelrc config file. This build script with parcel-bundler was producing the unexpected token error < and mime type errors in the browser console for me on manual page refresh.

"scripts": {
    "build": "parcel build ui/index.html --public-url ./",
    "dev": "parcel watch ui/index.html"
 }

Updating the build script fixed the issues for me.

"scripts": {
    "build": "parcel build ui/index.html",
    "ui": "parcel watch ui/index.html"
 }
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Comments

0

Maybe this can help,this worked for me in production. In your package.json file add homepage : address to your webpage just like the code below

"name": "client",
"version": "0.1.0",
"homepage": "abc.org", 
"private": true,
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Comments

0

For all those beginners who are trying to understand the concept but blown their mind in loading react without html script injection

here is my completed PR: https://github.com/tarunvella/react-learning/pull/3

hope this helps everyone that using webpack we can achieve bootstrapping react in root index.js with a index.html placed in public folder with your desired html node

everything is controlled by the bundler , so the bundler will inject the script tag from

<script defer="defer" src="/static/js/main.582af011.js"></script>

in head

below is how index.html body looks like in public folder during development

  <body>
<noscript>You need to enable JavaScript to run this app.</noscript>
<div id="react">React not rendered</div>

<!-- excluding html script injection -->

<!-- 
<script
crossorigin
src="https://unpkg.com/react@18/umd/react.development.js"
></script>
<script
crossorigin
src="https://unpkg.com/react-dom@18/umd/react-dom.development.js"
></script> -->
<!-- <script type="module" src="app.js"></script> -->
<!-- <script type="text/javascript" src="/Client/public/core.js"></script> -->
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Comments

-1

I just started learning React today and was facing the same problem. Below is the code I had written.

<script type="text/babel">
    class Hello extends React.Component {
        render(){
            return (
                <div>
                    <h1>Hello World</h1>
                </div>
            )
        }
    }
    ReactDOM.render(
        <Hello/>
        document.getElementById('react-container')
    )


</script>

And as you can see that I had missed a comma (,) after I use <Hello/>. And error itself is saying on which line we need to look.

enter image description here

So once I add a comma before the second parameter for the ReactDOM.render() function, all started working fine.

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