Uncaught (in promise) TypeError: Cannot read property 'createElement' of undefined(…)

Question

I needed to refactor my stateless functional component to a class. When I did so though, I keep getting an error where it looks like React itself is undefined.

import React from 'react'; import { Cell } from 'fixed-data-table';  const DataCell = ({rowIndex, columnKey, data, onMessageClicked, ...props}) => {   return (     <Cell {...props} onClick={onMessageClicked(data[rowIndex].Id)}>       {data[rowIndex][columnKey]}     </Cell>   ); };  export default DataCell; 

to

import { React, Component } from 'react'; import { Cell } from 'fixed-data-table';  class DataCell extends Component {    onCellClicked() {     this.props.onMessageClicked(this.props.data[this.props.rowIndex].Id);   }    render() {     const {rowIndex, columnKey, data, ...props} = this.props;     return (       <Cell {...props} onClick={onCellClicked}>         {data[rowIndex][columnKey]}       </Cell>     );   } }  export default DataCell; 

bundle.js:43248 Uncaught (in promise) TypeError: Cannot read property 'createElement' of undefined(…)

and when I go to that line I see

return _react.React.createElement(

I don't get it. How do I debug/fix this?

My full code for this app is here in case the code I'm posting is not related somehow.

Thanks!

Answer 1

Oh...

import { React, Component } from 'react';

needs to be

import React, { Component } from 'react';

:)

Answer 2

The OP has answered the question it self but with no reason so here's the reason! {Directly quoting from https://github.com/facebook/react/issues/2607#issuecomment-225911048" }

import { React, Component } from 'react'; 

is incorrect, should be

import React, { Component } from 'react'; 

There is no named export named React. It is confusing because React is a CommonJS module, and since you’re using ES6 imports, Babel tries to map the semantics but they don’t match exactly. { Component } actually grabs Component from React itself so you might just:

import React from 'react' 

and use React.Component instead if it’s less confusing.