CODEWITHSUNDEEP
javascriptreactjswebpackbabeljs
Jas Nagra
Jas Nagra

Reputation: 11

Warning: React.createElement: type should not be null, undefined, boolean, or number

Warning: React.createElement: type should not be null, undefined, boolean, or number. It should be a string (for DOM elements) or a ReactClass (for composite components).

I am currently putting a react page together and have come across the error above when I try to use es2015 style code. When i use the following code I get the error

var React = require('react');
export default class StoreApp extends React.Component {
  getInitialState() {
    return null;
  }

  render() {
    return (
      <div>
        <p>This should display on the screen</p>
      </div>
    );
  }
}

This works fine...

var React = require('react');

var StoreApp = React.createClass({
  render: function() {
    return (
      <div>
        <p>This should display on the screen</p>
      </div>
    );
  }
});

module.exports = StoreApp;

Im using babel with the following presets ['react','es2015'] any ideas whats going on here?

Upvotes: 1

Views: 3094

Answers (1)

Geraint
Geraint

Reputation: 3392

In an es6 you can't use getInitialState(). Use constructor().

e.g.

constructor(props) {
  super(props);
  //Set your state here using this.state = {};
  //or leave blank if you don't want anything set in state
}

If you're not putting anything in state you can even leave the constructor out in an es6 class.

Upvotes: 1

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