this.state is null inside render() ? about react-starter

[sokra]

constructor(props) {
  super(props);
  this.state = { foo: "bar" };
}

[AlastairTaft]

Instead of doing it in the constructor this seems to work for me

class MyComponent extends Component {
  state = {
    foo: "bar"
  }
...

[barrystaes]

Sorry, i forgot to set state in this example. (i updated my demo branch)

This works:

componentDidMount() {
  this.setState({foo: "works"});
}

My issue is that setting initial state "the normal way" no longer works:

getInitialState() {
  return {demo: "Hello #77"}
}

Did this change in React 0.13 perhaps? I could not find anything on that in API or specs docs.

(note: React.renderToString() does not call getInitialState() but i am not using prerender)

[EugeneZ]

@AlastairTaft That only works if you are using the proposed ECMAScript class fields syntax. For example by installing the relevant Babel plugin.

[sokra]

this.state isn't used. null is the default value. Why is this an issue?

[barrystaes]

😯 ah now i get this console warning.. (seems i missed this somehow)

Warning: getInitialState was defined on SomePage, a plain JavaScript class. This is only 
supported for classes created using React.createClass. Did you mean to define a stat 
property instead?

And indeed, i am not using React.createClass but

export default class SomePage extends React.Component {

And i was thinking this did the same thing, but apparently not.. insights welcome.

[barrystaes]

Am i supposed to do this?

constructor(props) {
  this.setState({foo: "bar"});
}

[barrystaes]

Thanks @sokra !
Seems there are more differences with regard to React.Component (React 0.13) than i realized.

If this is documented somewhere, i'd be happy to learn where. The only thing i found that mentioned such a thing was a coffeescript example.

[ibrahima]

@barrystaes thanks for that link, wish that was documented more prominently somewhere. I think it's a reasonable change but I wasn't expecting it from reading the tutorials that mention ES6 class syntax.

[thebadasscoder]

Make sure getInitialState is spelled correctly which was causing me to have that error. -__- Just take your time coding.

[sojelee]

@twilsonpierce awsome was getting same error, I mispelled getInitialState