I am trying to make ReactJS work with rails using this tutorial. I am getting this error:
Uncaught ReferenceError: React is not defined
But I can access the React object in browser console
I also added public/dist/turbo-react.min.js as described here and also added //= require components
line in application.js as described in this answer to no luck. Additionally,
var React = require('react')
gives the error:
Uncaught ReferenceError: require is not defined
Can anyone suggest me on how to resolve this?
[EDIT 1]
Source code for reference:
This is my comments.js.jsx
file:
var Comment = React.createClass({
render: function () {
return (
<div className="comment">
<h2 className="commentAuthor">
{this.props.author}
</h2>
{this.props.comment}
</div>
);
}
});
var ready = function () {
React.renderComponent(
<Comment author="Richard" comment="This is a comment "/>,
document.getElementById('comments')
);
};
$(document).ready(ready);
And this is my index.html.erb
:
<div id="comments"></div>
I was able to reproduce this error when I was using webpack to build my javascript with the following chunk in my webpack.config.json
:
externals: {
'react': 'React'
},
This above configuration tells webpack to not resolve require('react')
by loading an npm module, but instead to expect a global variable (i.e. on the window
object) called React
. The solution is to either remove this piece of configuration (so React will be bundled with your javascript) or load the React framework externally before this file is executed (so that window.React
exists).
I got this error because I was using
import ReactDOM from 'react-dom'
without importing react, once I changed it to below:
import React from 'react';
import ReactDOM from 'react-dom';
The error was solved :)
Possible reasons are 1. you didn't load React.JS into your page, 2. you loaded it after the above script into your page. Solution is load the JS file before the above shown script.
P.S
Possible solutions.
react
in externals section inside webpack configuration, then you must load react js files directly into your html before bundle.js
import React from 'react';
If you are using Webpack, you can have it load React when needed without having to explicitly require
it in your code.
Add to webpack.config.js:
plugins: [
new webpack.ProvidePlugin({
"React": "react",
}),
],
See http://webpack.github.io/docs/shimming-modules.html#plugin-provideplugin
Adding to Santosh :
You can load React by
import React from 'react'
import React, { Component, PropTypes } from 'react';
This may also work!
add
import React from 'react'
import { render } from 'react-dom'
window.React = React
before render function
this is because sometime error will pop up saying React is not defined
adding react to the window will deal with these problem
I got this error because in my code I misspelled a component definition with lowercase react.createClass
instead of uppercase React.createClass
.
if error is react is not define,please add ==>import React from 'react';
if error is reactDOM is not define,please add ==>import ReactDOM from 'react-dom';
I was facing the same issue.
I resolved it by importing React
and ReactDOM
like as follows:
import React from 'react';
import ReactDOM from 'react-dom';
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