What is the best way to connect a cognito user with a real database user?

Question

I have a react native app build with AWS Amplify. In this I have a custom authentication flow creating a cognito user and a post confirmation lambda trigger creating a real dynamoDB user. But the problem arise when I want to query this real user in my app home screen. At present I do it as follows, I first get the current authenticated user from cognito and then from the data receive I query real database user, but sometimes at first this fail to get the user but when I refresh the screen I get the user back. I want to know the best way to do this ?

My code,

import { Auth } from "aws-amplify";
import { DataStore} from '@aws-amplify/datastore';
import { User } from "../src/models";

const [user , setUser] = useState <User[]>([]);
const [ready, setReady] = useState(false);

const getUser = async () => {

try{
    const userData = await Auth.currentAuthenticatedUser();
    const currentUserPhone = userData.attributes.phone_number
    
    if(currentUserPhone){  
     await DataStore.query(User, d => d.Phonenumb("eq", currentUserPhone)).then(setUser);
     console.log("getting user in home");
     setReady(true);
    } else{
     setReady(false);
    }
  } catch(e){
    setReady(false);
    console.log(e)
  }

}

useEffect(() => {
    
  getUser();
     
}, []);

return(

<View>
 {ready === true &&(<Text>Hello {user?.name}</Text>)}
 {ready === false &&(<Text>No user</Text>)}
</View>

)

Answer 1

Ensure data is synced before querying. Call start and listen for ready event.

await DataStore.start();

Hub.listen('datastore', (data) => {
  const  { event } = data.payload;
  if (event === "ready") {
    // TODO
  }
})