react native how to get return from a promise

Question

my problem is i want to get a json from this function but all i get is a only a promise and why i choose this way because in app that i'm working on it works dynamicly but the only place that i see i can put this promise is render()

this is my code :

var userInfo = (async()=>{
    var value = await AsyncStorage.getItem("@user_info");
    value = JSON.parse(value);
    return value ;
  })();

and this is my result :

Promise {
 "_40": 0,
 "_55": null,
 "_65": 0,
 "_72": null,
}

but what i want to get is a json what sould i have to do ?

Answer 1

You have to call this function from componentDidMount and after the promise completes, call setState.

Here is a canonical example of how to do this:

class User extends React.Component {
  state = { user: null };

  render() {
     return this.state.user && <div>{this.state.user.name}</div>;
  }

  async componentDidMount() {
    const value = await AsyncStorage.getItem("@user_info");
    if (!this._unmounted) {
      const user = JSON.parse(value);
      this.setState({ user: user });
    }
  }

  componentWillUnmount() {
    this._unmounted = true;
  }
}